# Czech Mazda RX-8 DC conversion thread



## mira9_cz (Feb 27, 2013)

I decided to start my own thread to not ruin others discussions with my own troubles  

My name is Miroslav and I'm addicted to electro-mobility  First I must say that I'm car enthusiast in general, E.V. is not the only world for me. US cars is my passion but since the interesting ones are too heavy for reasonable E.V. conversion, I have decided to go Japanese sport sedan way. 

Since RX-8 came to market I loved Lincoln Continental-style suicide doors. I like that engine is placed behind front axle giving the car great driving performance. Unfortunately high-RPM Wankel engine always ruined RX-8 for me. No need to say my experience with electric cars was none, because I even thought about corvette V8 engine conversion.

Some stuff in life happened from back then like school finish, job changes, Microvett Pinguin 6 E.V. purchase and today I work for GWL-Power company as a technician. GWL is very well known LiFePo4 supplier, for those living in Europe at least I guess. 








For about four years already I'm collecting experience with electric cars and everything related. Some time ago I crossed The Bolt - Slovenian RX8 conversion. Suddenly Mazda was back in the game for me!

Now I think it is good time to thank DIYelectriccar forum members Mike (Skooler), Spyder e.v., kakheath and tcole6 for inspiration and courage to convert such a wonderful car as Mazda RX-8 is.

Thank you very much for everyone’s input. I hope my built will bring some new experience not just to me, but to everybody involved including you. If I’m incorrect, feel free to share your advice anytime. Also please feel free to Select, Copy and Paste my writings into your replies. Finally please forgive me for ruining English language.


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## mira9_cz (Feb 27, 2013)

I must say I envy you guys in Great Britain your used cars prices. In Czech Republic even 2003 models are unreasonably expensive. After about one month spent at used cars sales servers, I paid 4000 EUR for 2004 RX-8 with faulty engine in configuration I wanted: 6-speed manual gearbox, not that red leather interior, heated seats for fake feeling of warm and GPS display in dashboard for later use as a Amps, Voltage display. Later I found out that it is very easy to convert not-GPS equipped Mazda to display in dash version.

First good advice I can give to anyone who would like to do the same, it appeared to be very difficult to register car with faulty engine imported from different country. I found my Mazda in Vienna, Austria. Import and registration from EU is not difficult, however with car which is not running it is something different. It is also not possible to convert car to E.V. first and then register it in your country for a first time, E.U. car registration legislation is not ready for such a procedure. Of course if you don’t want to proceed full scale homologation, which is obviously terribly expensive and not needed for single car conversion. 

Luckily the guy whom I sold the Wankel engine to borrowed me some parts to make my Mazda ran at fossil fuel one last time.

As you can see, even 4 thousand EUR priced cars are not very beautiful. Technical condition was more important to me then appearance.



















As far as today I managed to get rid of unimportant parts. Some of them are quite easy to sell, like engine itself or exhaust. The rest I will have to store for some more time, at least it appears so. 




























I think it is no point to post many pictures of car without engine and other parts. However I pictured everything before, during and after, have it labeled and sorted. So if anyone wants something specific, please send me a message.


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## mira9_cz (Feb 27, 2013)

Now what is out of discussion: I'm here for DC conversion. I'm well aware of AC motor benefits. There are two main reasons for my decision. First is the fact that I was unable to find components for high-performance application for price enough so I could afford it. Second reason is simplicity of DC conversion if you have hi-performance application still on your mind. This is it, but please take in advance that my next RX-8 sure will be AC powered! 










And here it is, Kostov K11 Alpha when it arrived. Warp motor import to Europe is quite expensive because of import duty and shipping cost for heavy item. I also did not managed to find any old forklift truck or industrial DC motor that would fit my needs. Dual motor was also an option, but after some consulting with Mr. Plamen from Kostov I decided to try the Alpha. 

Hereby I confirm that RX-7 adaptor from canev.com fits RX-8 six speed gearbox and also to Kostov DC motors. Some of you might think that by purchasing components which you just bolt together is not very innovative or even interesting but I don’t care. 

In my previous job I worked for a company which specialized except others also in fitting EURO pollution standard friendly engines into Russian cars and trucks, which does not dispose of such an engine in original. I assisted in development of reduction flanges between engine and gearbox many times and my advice is if you can buy it, do it. You don't notice it immediately, but in long time use any misalignment, vibration, imbalance or other hard to find issue can cause disaster and damage many other parts and cause abnormal wear of component which you would not even expected. It needs to be done very well and development is expensive if you value your time. 

This is how far I managed to proceed until now. I also asked guy with carousel (I hope it is the right name for that machine) to modify original RX-8 flywheel for me. Originally it is purposely imbalanced, because they balance it together with Wankel engine crankshaft. Lot of material was taken off, it went from 7.6 to 5 kg!

This weekend I hope to fit motor with gearbox to the car so I could design the motor holders. Kostov K11 Alpha is shorter and should not collide with font axle as far as I measured. It also offers screws in motor body, which means designing the holders should be easy since there is no need to mount the motor only for front or back lid plus belly belt. I will post some pictures as soon as it will be in position.


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## mira9_cz (Feb 27, 2013)

Here are some topics for discussions, aka troubles which I will face in near future:

1 - Motor cables and their influence to electromagnetic compatibility. The shorter the better, right? How do you shield them? Do you lead plus and minus wire close next to each other?

2 – Heating. Does somebody have experience with this device? http://www.evworks.com.au/index.php?product=AIR-AC-RCVALVE
As far as I understand it can make car air conditioner to work as a heater in same principle as for example office / hotel air conditioners. It seems to be brilliant idea if I want to keep A/C in the car. 

3 – There goes my next question connected with previous one. How powerful electric motor do I need for A/C compressor? Also what RPM should A/C compressor work at? Is there some general experience? From what I experienced I think that Air conditioning in ICE powered car works very well also when standing at place with motor at idle. Therefore I should be able to count RPM for A/C compressor from Wankel motor pulleys diameters and Wankel engine standard idle. Am I thinking about this right? Isn’t there easier way how to find out?

4 – DC-DC converter. Generator at Wankel engine is 100Amps. Does it mean I really need at least 100 Amps DC-DC converter?

It appears to be big problem to find reliable DC-DC. At GWL we have tested some chines converters 72V DC to 13,5V DC and also 144V to 13,5V, but they seems to die pretty fast, even if I connected them through inductor. Right now we are using Meanwell SP350 unit in our test van. SP-350 is AC power source which can work with DC as well without violating warranty of the product. However it seems that at our nominal voltage 144V it cannot power board equipment correctly. It behaves strangely – it is pulsing 13,5V on output in non-regular pulses. This makes me think 144V input is just not enough to power at least headlights, taillights and motor fan. 

Since K11 Alpha is designed to work with 250V, this will be my pack voltage. I think this would fix Meanwell DC-DC issues, however I don't quite trust it anymore. So I checked Chennic offer and from what I have read generally there is good experience with them. However their 125A 250V top of the range product is quite expensive. 

Any other recommendations?

5 – Controller. I think I will proceed with Soliton 1 since K11 Alpha should handle 1000Amps peak and Soliton 1 is capable of performing that. Anyway I have Soliton Jr. right now at my disposal. So I think I will use it and proceed with smaller version, I will need money for batteries, right :-/ 

Am I correct that connections and also setup options of Soliton Jr and Soliton 1 are basically identical? So it should not be problem to just switch the controllers when I would decide to go for Soliton 1 later?

6 – Controller shielding. Do you shield your controllers? My experience with Soliton Jr. is that simple grounding is far not enough. Not to just listen FM radio in the car. I can hear increasing and decreasing humming sounds from speakers when pushing accelerator pedal even before motor starts to rotate, so I guess this is controller electromagnetic wave interfering with car stereo. How to prevent this? 

Since E.U. legislative is very unclear about registration of E.V. conversions, or at least here in Czech Republic, I want to make sure that I will do everything possible to pass possible EMC test later. I need to think about it during the built already so I was thinking of some cage around controller. Did you solved such issue?


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## mira9_cz (Feb 27, 2013)

Today I did not proceeded as far as I wanted to. I managed to wash transmission little bit and replace reverse gear sensor which caused leakage. 

I found two weights at the car which I suppose serve against vibrations. One is mounted at the end of gearbox, second - the long one is inside the "spine" which connects gearbox with differential. 
I installed them back after taking the picture but I was thinking about not to do so. They are quite heavy and while the vibrations source (ICE) is out, it should not cause any harm.


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## Duncan (Dec 8, 2008)

Those "weights" are Lancaster Dampers
I think you did right to leave them on - because they are located on the diff spine and gearbox there are probably there to eliminate specific vibrations from the diff/gearbox

Would be an interesting experiment to try the finished car with and without them


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## mira9_cz (Feb 27, 2013)

Duncan said:


> Would be an interesting experiment to try the finished car with and without them


Will try but for beginning I think it is better to not bring any unnecessary external influences which might later confuse me.


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## Tesseract (Sep 27, 2008)

mira9_cz said:


> ...
> 1 - Motor cables and their influence to electromagnetic compatibility. The shorter the better, right? How do you shield them? Do you lead plus and minus wire close next to each other?


I briefly discuss this in the Soliton manual, and have posted about this numerous times on here, but to summarize, the battery cables carry pulsating current so they will radiate magnetic fields. The most effective way to reduce this radiation is to minimize the "loop area" of the circuit. That means placing the battery cables side by side over their entire run (including inside the battery boxes - a detail that is often overlooked). The motor cables carry pulsating voltage so they will mainly radiate electric fields (same as a radio transmitter). To reduce this radiation you want to make the motor cables as short as possible and, optionally, enclose them in a metal conduit that is grounded to the vehicle chassis on both ends (NOT to the traction battery). 

Broadband RF noise is also produced by the brushes sparking. This can be reduced/eliminated by placing a small value film capacitor across the *armature* terminals of the motor (NOT across the motor as a whole!). For RFI suppression 0.1uF (100nF) is generally most effective, but anything from 47nF to 1uF will work. Note that a 100nF capacitor might have to carry 1A or more of current at 8kHz depending on the battery pack voltage, so use a physically large capacitor with wide/flat terminals. IGBT "snubber" capacitors are a good choice for this application.



mira9_cz said:


> ...
> 3 – There goes my next question connected with previous one. How powerful electric motor do I need for A/C compressor? Also what RPM should A/C compressor work at?


From our tests here, A/C compressors require 1-3kW, depending mainly on the size of the car and the surface area of exposed glass. You'll have to experiment with the idle RPM to see how low you can set it and still get cooling, but 800RPM would be a good starting point.

As for installing a reversing valve to turn the A/C into a heat-pump, I am not an A/C tech, but my understanding is that you have to replace the orifice tube with a bidirectional expansion valve otherwise the efficiency in heating mode will be terrible.



mira9_cz said:


> 4 – DC-DC converter. Generator at Wankel engine is 100Amps. Does it mean I really need at least 100 Amps DC-DC converter?


Modern cars have a lot of electronics, but you shouldn't need 100A unless the power steering is electric. That alone will draw 40-60A.

As crude/ridiculous as this might sound, if you are going to idle the motor to run the A/C compressor, it might make sense to build a bracket to drive the alternator and any other belt-driven accessories as well. While an alternator is less efficient than a DC/DC converter, it is definitely a lot more reliable. The sad truth is that *none* of the DC/DC converters typically used by DIYers in EVs are worth a crap - they are the least reliable component in most conversions by far, actually.



mira9_cz said:


> 5 – ...
> Am I correct that connections and also setup options of Soliton Jr and Soliton 1 are basically identical? So it should not be problem to just switch the controllers when I would decide to go for Soliton 1 later?


Most of the settings are the same; the exceptions are the obvious ones like motor current, motor power, battery current, etc. The low voltage connections are the same, but different stud sizes are used for the high voltage terminals - 3/8" (10mm) on the Soliton Jr; 1/2" (13mm) on the Soliton 1. 




mira9_cz said:


> 6 – Controller shielding. Do you shield your controllers? My experience with Soliton Jr. is that simple grounding is far not enough. Not to just listen FM radio in the car. I can hear increasing and decreasing humming sounds from speakers when pushing accelerator pedal even before motor starts to rotate, so I guess this is controller electromagnetic wave interfering with car stereo. How to prevent this?


It is rare for our controllers to radiate enough noise to interfere with even an AM radio, much less an FM radio. This type of problem is best solved by installing a noise filter on the power leads to the radio, first. Only if that doesn't work should you attempt more extreme measures (which I already outlined above).


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## mira9_cz (Feb 27, 2013)

Thank you for valuable information provided. As for electromagnetic interference I use old long and medium wave radio to hear more, but for test van even FM frequency is disturbed a lot. I will think of some smarter way how to lead motor and pack cables and check what more can I do for improvement. I will also browse the forum more for your other posts related with this issue.



Tesseract said:


> ...Modern cars have a lot of electronics, but you shouldn't need 100A unless the power steering is electric. That alone will draw 40-60A.


This is the case for Mazda RX-8. It explains need for a big generator. 



Tesseract said:


> it might make sense to build a bracket to drive the alternator and any other belt-driven accessories as well. While an alternator is less efficient than a DC/DC converter, it is definitely a lot more reliable.


This is disadvantage of Kostov K11 Alpha application. There is no option how to fit any bracket with pulley to drive accessories. It relies only at active fan cooling and I can think of no way how to fit a pulley on it. 
Some gearboxes has a lid for optional output for driven accessories such as winch, slow plow, etc. This could be used as well but this is not the case of Mazda RX8 6 speed gearbox. I'm afraid I will have to rely on DC-DC.


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## mira9_cz (Feb 27, 2013)

For successful connecting motor with gearbox using an adapter from canev.com, you will also need new clutch pilot bearing with gasket. 










Mazda part number for bearing is N326 11 D03, for gasket it is 181 11 404A.


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## mira9_cz (Feb 27, 2013)

There was not much time to continue at Mazda, but my last progress is quite significant step. First we have fitted Kostov motor with canev adaptor, clutch and eventually gearbox. Bolts that came with canev adaptor are too short. I guess RX-7 gearbox flange (for which the adaptor is designed) is little but thinner. Unfortunately original Mazda bolts that holds gearbox together with wankel engine are too short to be used with canev adaptor as well. It is necessary to buy new longer bolts. 



















Then we have fitted motor already connected with the gearbox to the car. It was hard work, the fitting itself took about two hours. Kostov K11 Alpha weight is 75 kg, so using some kind of crane or lifter is necessary. You can get the idea how we have proceeded from the picture below. 



















There is not much space left from the steering rack, but at least it was not necessary to change the angle of the gearbox position in the car.










I'm not sure how much I need airflow blowing from the grill in front bumper for cooling the engine. There is very nice place for battery pack in front of steering rack. I hope there will be sufficient air flow going through steering rack from the bottom of the car.


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## Studebaker (Jan 22, 2012)

Great job mate. Don’t worry guys ain’t responding in large number. Probably still trying to figure out, where the hell, a Czech could get this kind of money from. They’ll come around. Eventually. 

What’s that cute black thing in front of the axle beam doing ? Giving hand? Or just checking if her(his) master didn’t go mad?

Don’t let up mate.

Cheers 
Chris


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## Rastusmalinus (Sep 26, 2011)

Great pictures! I'm considering the RX-8 as my next project. I am glad you said that the RX-7 adapter from can-ev will fit. Aside from the battery racks, I think the adapter/ coupler job was the worst part of doing my conversion.


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## kortas (Apr 18, 2012)

Studebaker said:


> Great job mate. Don’t worry guys ain’t responding in large number. Probably still trying to figure out, where the hell, a Czech could get this kind of money from. They’ll come around. Eventually.


In the Czech Republic we call it "high tech & low life", or LiFe is good


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## Studebaker (Jan 22, 2012)

Watching Breaking Bad, I learn new things about Czech Republic. Looks like life there is really good these days.


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## samwichse (Jan 28, 2012)

Hey, if you're looking for a cheap DC-DC converter, see if you can lay hands on one of these babies:
http://www.ebay.com/itm/2000-HONDA-INSIGHT-DC-POWER-CONVERTER-INVERTER-PCU-OEM/390627473221?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D17397%26meid%3D1333436633197238969%26pid%3D100011%26prg%3D8093%26rk%3D1%26rkt%3D5%26sd%3D321179119171%26

They can usually be had around $120-140 US, and in 11 years of the insightcentral.net forum, there's not been a posting about one that failed. Takes ~70V - 220V (cuts out above or below that). Rated for up to 70A I believe.

Here's a link to the necessities to make it work:
http://www.insightcentral.net/forum...-inverter-needed-experiment-2.html#post209599

And to the whole thread:
http://www.insightcentral.net/forum...s/21025-dc-dc-inverter-needed-experiment.html


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## mira9_cz (Feb 27, 2013)

Studebaker said:


> Great job mate. Don’t worry guys ain’t responding in large number. Probably still trying to figure out, where the hell, a Czech could get this kind of money from. They’ll come around. Eventually.
> 
> What’s that cute black thing in front of the axle beam doing ? Giving hand? Or just checking if her(his) master didn’t go mad?
> 
> ...


Thank you Chris, I appreciate it. As my friend Kortas said, it is pretty much hi-tech, low-life style although I would like it to be otherwise. It is basically about how much are you able to give up to reach your dreams ;-) As you can clearly see from the pictures, our conditions and equipment are far from professional workshop. 

I can see you have noticed my fathers nameless cat  Yes, she is a little helper and rich resource of paw print on my cars.


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## mira9_cz (Feb 27, 2013)

Rastusmalinus said:


> Great pictures! I'm considering the RX-8 as my next project. I am glad you said that the RX-7 adapter from can-ev will fit. Aside from the battery racks, I think the adapter/ coupler job was the worst part of doing my conversion.


This is why I started the thread. I think RX-8 was designed to become E.V. one day! Even creators were probably not aware of it back then  
I will be happy if my posts will help anyone to succeed in similar task. I document everything so if anybody needs something specific, just ask! 

Yes, RX-7 adapter from CAN-EV will fit 6-speed RX-8 manual gearbox. Bolts included are short however.


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## mira9_cz (Feb 27, 2013)

samwichse said:


> Hey, if you're looking for a cheap DC-DC converter, see if you can lay hands on one of these babies:...


Thank you very much Sir! This is good information. I will examine it further and I must first be sure about my current requirements since the power steering is electric. I'm also not sure how much power those xenon headlights needs. 



To be honest I postponed DC-DC issue a little bit, trying to use all free time to reach some real progress at the car itself instead. As soon as motor holders will be finished, battery boxes are the next challenge. I'm also not really sure yet where to place the soliton controller. I doubt I will be able to fit it instead of fuel tank as I wish to. I would also like to use the space under the hood for the cells, because with 250V pack voltage I'm affraid I will need a lot of space.. So the spot behind the front grill seems to be good idea for now.
First things first, so I think you will hear of me as soon as I will have some pictures of motor holders.


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## Wheelnutter (Apr 7, 2009)

Thanks for all the information. Hoping in the near future to start a conversion on an RX8.
Your pictures and designs are very helpful.


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## skooler (Mar 26, 2011)

Good to see it coming on well 

As for batteries, I have managed to fit 38 * 100AH cells in the space behind the front bumper. That's a single tier as low down as they can go. I have space for a further 24 above (see my build thread) but haven't bothered as 74 cells (75 mile solid range) is enough for me. 

I also cut out the boot (trunk) floor and have 36 cells in there, again, see my thread.

Just a heads up, the 4KW TC Charger fits perfectly in the area the fuel tank lived in, you can actually get two in there.


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## mira9_cz (Feb 27, 2013)

skooler said:


> Good to see it coming on well  As for batteries, I have managed to fit 38 * 100AH cells in the space behind the front bumper. That's a single tier as low down as they can go. I have space for a further 24 above (see my build thread) but haven't bothered as 74 cells (75 mile solid range) is enough for me. I also cut out the boot (trunk) floor and have 36 cells in there, again, see my thread.


Impressive job with battery boxes! I checked your thread and as far as now I can't see better way to perform this thing. Today I have actually stripped the boot from carpeting and started thinking what to do next. 



skooler said:


> Just a heads up, the 4KW TC Charger fits perfectly in the area the fuel tank lived in, you can actually get two in there.


Thank you very much for this information, today I measured a bit and I think I can fit Soliton Jr. there as well. 
Please tell me - you mean TC Charger in this case (of this size)? : http://www.ev-power.eu/Chargers-TC-3-kW/


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## mira9_cz (Feb 27, 2013)

Today we have managed to finish motor holders. I think it came out nicely. They are not symmetrical. Left one uses left mounting spot at the body of Kostov motor. Right holder utilizes both right and bottom mounting spots. The upper mounting spot is unused to save space above motor. Both holders are relatively long to be enough lever to handle motor torque. We have managed to use original silent blocs, in their original positions of course.



















Except striping the trunk from carpeting, other thing successfully done today is the vacuum pump holder. I have dared to position it very close to interior space, but as far as I can tell, these hella pumps are very quiet. With vacuum switch properly set it works very well even without vacuum reservoir at our GWL-Power test electric van.
Why somebody uses vacuum reservoir anyway? Does it significantly shorten the time of vacuum pump working? Or what is the primary reason?


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## mora (Nov 11, 2009)

mira9_cz said:


> Why somebody uses vacuum reservoir anyway? Does it significantly shorten the time of vacuum pump working? Or what is the primary reason?


It is the opposite. If you have bigger space to evacuate (vacuum reservoir) your pump will run longer. Your EV will stay quiet for longer period of time if vacuum pump is not running on every pedal press. I believe these pump motors are not meant to be working at every pedal press and should have enough time for cooling. Work remains the same but cooling (and working) period increases. I have no idea how long and how often those run on original installations though.


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## mira9_cz (Feb 27, 2013)

mora said:


> It is the opposite. If you have bigger space to evacuate (vacuum reservoir) your pump will run longer. Your EV will stay quiet for longer period of time if vacuum pump is not running on every pedal press. I believe these pump motors are not meant to be working at every pedal press and should have enough time for cooling. Work remains the same but cooling (and working) period increases. I have no idea how long and how often those run on original installations though.


Thank you for reply, this is what I had on mind basically, but wrote it wrong. Simply it should save vacuum pump. I wondered how significantly vacuum reservoir extends the period of vacuum pump being inactive. I will test it on my own, I have the C4 Corvette vacuum canister at home, so I will try to connect it to the system and see what it does.


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## mira9_cz (Feb 27, 2013)

Yesterday we have cut hole into the boot case floor and measured and measured. I think I have spammed Skoolers thread with this kind of information enough, so just in short: 

If you want to make rear battery box as large as possible, you will face the complications with rear stabilizer - it is simply too much "in space", which could be used for making the box a bit longer. The same, perhaps even worse situation is at the spot, where rear axle is mounted to the body sub-frame. Skooler solved this by repositioning the stabilizer and mounting it to the battery box support frame. The spot where the rear axle meets the subframe Skooler solved very nicely by hiding these spots into "pockets" of his box, which of course reduced a space for cells a little bit. 
As far as I can tell now my solution will be less advanced - I will make shorter battery box that will not collide with rear stabilizer, nor the axle mounting spots. Therefore my rear box will sure be smaller, but as far as I have measured, I would not position any more big cells (Winston 200 Ah WIDE or two Wina 100 Ah in parallel) even with "pockets" as Skooler did. I hope I will not regret it in future.




























I plan to post simple drawings of battery boxes with dimensions later as soon as the job will be done.


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## ScottyDont (Sep 29, 2013)

Looks good, do you have any photos of the fuel tank space and how much can fit in there?

I think the K11 Alpha will suit the RX-8 well, great to see it fits the canev adapter. Did you upgrade the clutch for the extra torque or will you limit the motor to around the same as the stock engine?

Look forward to seeing your ev completed


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## kennybobby (Aug 10, 2012)

*rear stabilizer*

Just a thought for the rear battery box--It looks like the rear stabilizer bar has a bend in the center. If that bend interferes with the usable volume for the battery box, then just cut it out and weld in a straight steel rod/sleeve to route it out of the way. It only functions as a torsion bar to try to hold down the inside wheel and reduce body-roll during hard cornering, and the shape and location can be modified to fit in your conversion.


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## skooler (Mar 26, 2011)

Any progress to report?


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## mira9_cz (Feb 27, 2013)

skooler said:


> Any progress to report?


Unfortunately there is nothing new to report. My dad decided to fit Jeep Cherokee solid front axle instead of original independent suspension to his Ford Ranger. So there is big pickup truck hanging at the car lift for over Month already and there is still some work to do. He is thinking about new position for dumpers currently. With some luck he will finish the job next week, or at least Ford should be able to stand at his own front wheels again (so it can be pushed out in favor of Mazda further progress)


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## mira9_cz (Feb 27, 2013)

ScottyDont said:


> Looks good, do you have any photos of the fuel tank space and how much can fit in there?
> 
> I think the K11 Alpha will suit the RX-8 well, great to see it fits the canev adapter. Did you upgrade the clutch for the extra torque or will you limit the motor to around the same as the stock engine?
> 
> Look forward to seeing your ev completed


Thank you and sorry for long time without reply. I also hope K11 Alpha will suit the car well. I'm also afraid that stock clutch will not be enough, although I still believe that I can expect the best from Japanese sports car. I do not think it will start slipping immediately, because obviously I will be careful for more then first few miles, so I plan to stick with existing clutch and pressure plate until I will experience slipping. As soon as this will happen I will order some performance clutch parts, I'm sure Americans have something for dragster racing purposes 

I searched for some pictures of fuel tank space but there is nothing usable. As the shape of the space is strange, it is not obvious how deep it is from any pictures I have found. As soon as I will manage to get Mazda at the lift again, I will make some better photos.


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## mira9_cz (Feb 27, 2013)

*Re: rear stabilizer*



kennybobby said:


> Just a thought for the rear battery box--It looks like the rear stabilizer bar has a bend in the center. If that bend interferes with the usable volume for the battery box, then just cut it out and weld in a straight steel rod/sleeve to route it out of the way. It only functions as a torsion bar to try to hold down the inside wheel and reduce body-roll during hard cornering, and the shape and location can be modified to fit in your conversion.


Hello and thank you for suggestion. Also sorry for long time without reply. 
Honestly I'm afraid to change anything at the car that could have some impact to driving behavior or safety. Simply said I still have the worst case scenario in my mind - that I will have to pass some Dekra or TUV inspection. Any modification of complete assemblies like suspension might be a problem. 

Also even with stabilizer off, I could get maximum about 8 inches more space which still will not allow me to add second layer of cells to the rear battery box anyway.


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## mira9_cz (Feb 27, 2013)

So the car lift is finally free of my dad's pickup truck and I had some chance to continue. Progress is not very big, but it is important. We have re-measured possible dimensions of rear battery box. I had some ideas how to make it bigger and here is the result:


















The biggest progress at all I think is the fact, that I already know what cells I will use for my traction pack. I received very good offer of used WINA 100Ah cells. They were installed about a year in the prototype E.V. which I took care of, so I know exactly the history and how they were treated. They will be available in half of December I hope. It is 144V, 200Ah pack so there I have 96 cells. It is unfortunately not enough for Mazda - to reach 250V traction voltage I need 166 cells if I want 200Ah pack. However 84 of them is enough to build 100Ah pack for testing and driving around a town!

I'm little bit afraid of troubles later when I will purchase remaining 70 cells. I know that balancing old cells with brand new ones is always an issue, but I strongly believe in quality of Wina cells over time. 
The reason I will go for that offer is that Wina cells are truly the best what you can buy from widely available LiFePo4 cells, especially in discharge power capability. Also power density is better - they are just smaller then Thundersky-type cells. Also I must say I'm not sure if I would handle to build pack from A123, or let's say I do not want to learn it at so expensive battery pack.


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## mira9_cz (Feb 27, 2013)

Hi guys. I'm standing before decision which I'm not quite sure about. With 144V 200Ah battery pack made of 96 Wina 100 Ah cells I actually received also Kostov K9 144V D.C. motor, Soliton Jr. Controller and some other stuff.
So it came to my mind to put this very configuration into Mazda, having not so powerful motor, but twice as battery capacity. Then I realized that perhaps I'm thinking it wrong. Is capacity what really matters, or is it 

Here is what I'm a bit puzzled about now: Having 200Ah pack at 144V(48 cells) traction voltage is the same as having 100Ah battery pack at 288V (96 cells), right? In theory power to discharge is the same, but how that works in reality. Is there some point where some components are not so efficient and therefore it is more advantageous to use higher voltage, or vice versa?
Yes, in both cases different Kostov motor would be used. K11 Alpha should be more efficient then K9 because of passive cooling absence, but I don't think this is what I should be concerned of. I'm sure there will be thread about this exactly somewhere, please feel free to send me there. Thank you very much for any advice.


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## mira9_cz (Feb 27, 2013)

Here it is:


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## tylerwatts (Feb 9, 2012)

Mira. It won't matter at the motor as the Soliton will meter how much current and voltage goes to the motor, regardless what it is taking from the pack. It essentially transforms the power to what the motor needs. 

Now for. Licensing and safety the lower voltage is better as it lowers likelihood of arcing and makes insulation easier. In future if you expanded your pack you could reconfigure it to higher voltage for more power. Say you got a bigger motor. 

So I hope that helps. If this pack meets your range needs and you get enough performance from 144v configure it for lower voltage. The soliton will manage what actual voltage and current is fed to the motor.

PS: that is a smart adaptor. I hope those pillar spacers handle the torque well is all. 
Regards 
Tyler


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## mira9_cz (Feb 27, 2013)

Thank you Tyler for your advice. I sure appreciate it. From beginning I counted with higher voltages. I think even if I would "switch back" to 144V now, I would certainly designed everything as much as possible to be able to sustain later possible upgrade to 250V. I do not really know how postponing high voltage issues could help.


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## mira9_cz (Feb 27, 2013)

I think I should present my issue less theoretically and more directly.

I really do not want to design new holders for Kostov K9, knowing that these will be temporary anyway. I also know that donor E.V. from which I have all the components from operated with 144V, 200Ah. It actually have met my range requirement - 130 km plus minus. The donor was a van carrying some weights to simulate load and it also was not very aerodynamic. I have no reason to doubt that in the very same configuration Mazda will be able to do the same range at least.










Now I need to find out that if I will reconfigure the battery pack to higher voltage (and lower capacity), will I still be able to reach the same driving range as I would reached with lower voltage configuration (and higher capacity)? Theory says yes, as Tyler wrote, it depends on what goes through Soliton. 
I expect that with higher voltage bigger motor I will reach the same level of performance under less current, then I would have to draw from the pack with lower voltage smaller motor. Right? Soliton will convert the power with same efficiency in both cases I suppose, what about efficiency of smaller vs. bigger motor?


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## tylerwatts (Feb 9, 2012)

Mira
The capacity is the same, V x A equals P! You will just use current rather than voltage to make the same power. The benefit of voltage is less transmission losses, as high current loses power as heat through resistance in wiring and joints etc. 
Search the forum but I'm sure guys run the Kostov to higher voltages, I'd hesitate to say up to 200V. Just be careful not to run too much current, as current is the limiting factor, as I said, heat will damage the motor. The conversion losses of the Soliton will be insignificant between the different voltages. Could you not consider a 220v k9 motor rather? Just ask Kostov to swap them with the price difference? Then you start on the best foot. I doubt you would need a k11 but you never know what you might wanti suggest the k9 with good cooling is plenty in the RX8 and work to keep weight down. 

Why do you say the 'holders' are temporary? Are these the mounts for the motor you mean? This pack should be good for close to the 130km range you mention but remember you will enjoy driving the car more enthusiastically!


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## tylerwatts (Feb 9, 2012)

Assuming you have a little more charged voltage in your pack than 144v and you don't exceed 80% discharge you should easily meet 130km range with 200w/km consumption. Knowing the RX8 is fairly aerodynamic and Mazda design their sports cars with minimal rotation inertia this should be conservative. And you'll have good performance with a k9 motor through the standard transmission. I believe some people have run these motors up to 8000rpm but wouldn't recommend above 7000 and not too often. Fortunately the Kostov motors like rpm and perform well so are suited well to the high gearing of the RX8. 

Your build should be a very exhilarating drive when complete! Will you have much difficulty licensing it?


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## kortas (Apr 18, 2012)

I suggest to keep K11 and start saving money for Shiva and doubling the cells 

I guess that fully charged Wina 100Ah will be able to provide 700 - 1000A assuming voltage slightly over 2V per cell... so this configuration could make about 150 - 200kW of peak input power (96 cells), which can be fun. Most probably a bit more fun than feeding my Fiat 126 with 55kW even considering it has half the weight compared to your Mazda


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## tylerwatts (Feb 9, 2012)

kortas, Mira has a K9 144v motor currently. So it will cost money going to the k11. 

Mira, the 100ah cells should prefer to stay around 5c discharge which is 500A so at 280V will feed the controller 140kw. With the torque of an EV that will feel about standard performance for the RX8 so pretty good. I would recommend getting it built as is and not worrying about drag race performance yet.


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## mira9_cz (Feb 27, 2013)

Thank you again Tyler for valuable input. First please let me correct you - I have both K9 and also K11 Alpha motors. This discussion I have started about 250V or 144V is not just some theory, I actually have both motors AND also enough cells to build various battery packs. 

Now I can see why you probably advice me what you do. Please take in advance that first I have bought Kostov K11 Alpha aiming for 250V, 200Ah battery pack and Soliton 1 in Mazda. I'm aware it is little bit racing car what I'm building, but this is what I want. K11 Alpha is installed already on that pillars that I you doubt about. Now I'm working on battery boxes. 

As usually, some unplanned stuff happened and I received an offer of 144V, 200Ah battery pack, but the condition was to buy also a test vehicle together with the battery. So that silver test van is now equipped with Soliton Jr and Kostov K9. You can imagine that investment delays Soliton 1 purchasing, as well as rest of the cells for battery pack I originally aimed for. But it gives me the chance to finish Mazda now and finally stop using gas stations! As you already noted, I might not use capability of K11 in Mazda at all and I will stick with Soliton Jr. and current pack, who knows. Now I must use what I have to get Mazda on the road.


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## mira9_cz (Feb 27, 2013)

There is still something I would like to refer in your posts, Tyler

>>> This pack should be good for close to the 130km range you mention but remember you will enjoy driving the car more enthusiastically! Assuming you have a little more charged voltage in your pack than 144v and you don't exceed 80% discharge you should easily meet 130km range with 200w/km consumption. Knowing the RX8 is fairly aerodynamic and Mazda design their sports cars with minimal rotation inertia this should be conservative. And you'll have good performance with a k9 motor through the standard transmission. 
// Thank you for assuring, it is nice to see it written  I hope there will be enough reserve to be able to afford to keep DOD at positive levels.

>>> I believe some people have run these motors up to 8000rpm but wouldn't recommend above 7000 and not too often. Fortunately the Kostov motors like rpm and perform well so are suited well to the high gearing of the RX8. 
// I have no reason to overload K9, because I have K11 installed already. I want to avoid any contact K9, keeping it in silver van, waiting for resurrection as soon as somebody will want electric van.. 

>>> Your build should be a very exhilarating drive when complete! Will you have much difficulty licensing it? 
//Thank you Tyler, I truly hope in the same thing. Regarding licensing, homologation of M1/N1 cars had brought me bread to the table for five years and I tried to get as many knowledge as I could. No I'm in different business, but I think I can say I know what I'm facing to and also what can I do to not get screwed by authorities. Fact is that E.U. law provides quite good options, you just can't get discouraged by officers who have no idea about it. 

>>> Just ask Kostov to swap them with the price difference? Then you start on the best foot. I doubt you would need a k11 but you never know what you might wanti suggest the k9 with good cooling is plenty in the RX8 and work to keep weight down. 
// That way I would have to install K9 into the car which I want to avoid, but this you already understand by now. But sure, K9 would be also possibly nice fit for Mazda RX8, especially 220V version.


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## tylerwatts (Feb 9, 2012)

Oh Mira, I apologize. I misunderstood that you only have the k9 in the car, and one of the pics was showing that motor. The k11 alpha is a wonderful motor. I suggest giving it all the voltage you have then. Do not worry immediately about a larger pack, but be sure to plan for space and connection to increase the size in the future. 
Do you have a Soliton 1 already then? This is good also as the programming can be set to allow higher current at low motor speed and to lower the current as volts are required for rpm hence not exceeding the discharge margin of your batteries but having maximum torque at low speed. 
This leads to a separate issue however. The RX8 is designed for a low torque rotary engine and therefore the transmission is not designed to handle large quantities of torque in sudden bursts. Either set the ramp rate slow on the controller so the torque builds smoothly rather than suddenly or ensure you do not use the lower gears, as your clutch will suffer and the differential and transmission support structure will suffer and possibly fail also. You don't need the torque with the high gearing of the RX8 anyway and running lower current will extend the battery life and reduce the need for extensive cooling of the motor and controller. You might not need motor cooling at all if it is always spinning fast, say above 2000rpm, as the gearing for the ice would normally dictate. 

Have a word with Scooler also about what gearing he uses etc as he has quite a good amount of mileage in his RX8 already with the standard transmission ratios.


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## mira9_cz (Feb 27, 2013)

As far as I spoke with guys who race with Mazda, gearboxes are very reliable. They are used both in RX-7 and 8. Clutch is another issue, I'm ready to buy some performance clutch parts later as they will be needed. I plan to proceed slowly since I need to have the car reliable first, and then start trying what it is capable of. 
Regarding the gear ratio, I think it will not be so bad. There must be 1:1 gear, so that one, and the gear under it will be proper for most of the time. There is one alternative factory differential which I might use to change things in worst case. Perhaps there are some alloy tuning component since RX-8 is considered for japanese import tuner car in US, but honestly there are things that scares me more, like DC-DC.


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## mira9_cz (Feb 27, 2013)

To summarize my battery pack voltage issue, I will use all 96 cells that I have to build 288V 100 Ah battery pack, hoping to provide me the range I need. 

So I can start choosing charger. I hate the fact that I might change the battery pack voltage in future again (to 250V doubling 100AH cells for 200Ah pack capacity). Charger which would allow output voltage change would save me! 

I must study more about open source charger. They say one thing I like: "Manual control method - charger can be programmed for any input / output current / voltage at any time in field - no need to do any factory setting!" 

Tyler: No, I do not have Soliton 1 yet, but I have Soliton Jr.


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## Duncan (Dec 8, 2008)

mira9_cz said:


> There must be 1:1 gear, so that one, and the gear under it will be proper for most of the time. .



If you are thinking of using a 1:1 most of the time why not just drive the propshaft from the motor direct?

On my machine using direct drive meant that the motor lived where the gearbox would have gone 
Which freed up all of the space where the motor would have had to go

Not to mention eliminating all possible problems with gearboxes and clutches and saving a useful amount of weight


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## tylerwatts (Feb 9, 2012)

Mira
Duncan has a good point. But as you say you wish to keep a second gear for lower speed. I was going to suggest maybe running direct to the differential with the k11 and good cooling as the RX8 has a high ratio diff gear and probably a number of after market options also. And the Soliton can deliver full current for torque and then at higher ratios it can reduce the current and increase voltage for higher motor speed. The Kostov motors handle rpm well as we've said which is good. 
What speed and acceleration do you want from the car? We can calculate the traction available and torque possible to work out how much power you can actually use to determine whether the gears are needed. Remember Crodriver's BMW was direct drive as it wouldn't maintain traction anyway so gears weren't needed. 
Also, check out the black rx7 build on here, possibly Duncan's vehicle actually but I can't remember, as I think it runs direct drive also. 
When we know what performance you want we'll see if you need anything bigger than the Soliton jr also.


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## mira9_cz (Feb 27, 2013)

Duncan said:


> If you are thinking of using a 1:1 most of the time why not just drive the propshaft from the motor direct?
> 
> On my machine using direct drive meant that the motor lived where the gearbox would have gone
> Which freed up all of the space where the motor would have had to go
> ...


Hello Duncan, thank you for your input. I agree with everything you mentioned, but I'm simply afraid that K11 might not be enough for drive offs. Or better said I think high currents are unnecessary for drive offs and I can easily shift something to save the motor from unnecessarily high currents. I have experience with Kostov K9, there is no chance for direct drive. K13 is made directly for this application, so I expect K11 to be something in between and I simply did not want to risk it without gearbox at first. 

If I will later see that gearbox is not needed at all, I will go for direct drive immediately, saving gearbox and Canev adaptor for smaller motor.

Thank you Tyler for mentioning proper example cars to study. I will check it. Crodrivers BMW is a masterpiece, good example. I had not see Duncans RX7 yet, I will check it as well. 

>>> What speed and acceleration do you want from the car? We can calculate the traction available and torque possible to work out how much power you can actually use to determine whether the gears are needed.
//It is very hard to say specific numbers, I never thought about it this way. I want it to be able to reach 130 km/h highway speed and be efficient in this regime. This is the only serious requirement, which I think is easy to meet with current configuration. Everything above this requirement I will consider as a bonus, but truth is I expect quite lot of "bonus" there.


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## tylerwatts (Feb 9, 2012)

Ok so that is easy to work to, what power is required to maintain that speed? So what is the optimum rpm for the motor at the given 288V rating of the motor? Maybe this voltage will differ by the parameters of the Soliton, but this can be factored. Does the rpm of the direct drive ratio to the diff match the motor rpm for optimum efficiency? Is the geared rpm better? Remember the transmission still has fixed gears, just a few to choose from. So now is direct or transmission ratio better for efficiency at 130km/h? Yes/no?

But also, what other conditions might you experience where the single diff ratio could be a compromise? Say climbing a 5% hill at 130km/h. Can the motor handle the increased power requirements for maybe a 10min climb (worst case example)? What about acceleration? Is 400nm torque enough? If the standard ice gave half this only briefly in the upper region of the power band and 3rd gear is nearest to twice the diff ratio then expect this level of acceleration with the fixed ratio. This is likely plenty anyway, and the traction calculations will tell you if it is too much. Also remember if you fit low resistance tyres you have alot less grip also so more power is no help or benefit anyway. Finally, what sort of cooling will your motor need to maintain these high current loads for longer periods? Remember with gears you need less power for the same acceleration as you have a mechanical advantage. And you may suffer higher overall average energy consumption with a single ratio but you save quite alot of weight which can either improve your efficiency or be offset by more batteries for increased range without the weight or space penalty. I think the benefit of having all batteries in the engine bay and a single motor in the transmission tunnel with no weight change or distribution is the optimum condition as few other vehicle modifications are needed then. 

Forgive me Mira, I do not have the formulas to hand to work out traction and performance figures but they are on the forum and I'm sure others will know them well and be able to fill in for me. I'll try work them out if I get chance though. I'm excited about your build and wish you the best with it!


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## Duncan (Dec 8, 2008)

mira9_cz said:


> I had not see Duncans RX7 yet, I will check it as well.
> 
> >>> What speed and acceleration do you want from the car? We can calculate the traction available and torque possible to work out how much power you can actually use to determine whether the gears are needed.
> //It is very hard to say specific numbers, I never thought about it this way. I want it to be able to reach 130 km/h highway speed and be efficient in this regime. This is the only serious requirement, which I think is easy to meet with current configuration. Everything above this requirement I will consider as a bonus, but truth is I expect quite lot of "bonus" there.


Hi
No RX7 - just my "Device"

RX7's have a diff ratio of about 4:1 - very similar to my Subaru setup,

But you will be a fair amount heavier 
(The Device is 710Kg)

So you will need about 50% more torque,

At present with an OpenRevolt and 500amps performance is brisk - but not shattering
About 8 seconds to 100Kph - 130Kph maximum
I think that with ~ 700amps I would be able to spin the back tires,
If your motor has similar characteristics to my 11 inch, 100Kg fork lit motor them 1000amps should be getting you into tire spinning territory

Losing the gearbox does make everything so much simpler,
no clutch, no clutch pedal, no gear linkages

http://www.diyelectriccar.com/forum...-dubious-device-44370p8.html?highlight=duncan


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## mira9_cz (Feb 27, 2013)

tylerwatts said:


> Ok so that is easy to work to, what power is required to maintain that speed? So what is the optimum rpm for the motor at the given 288V rating of the motor? Maybe this voltage will differ by the parameters of the Soliton, but this can be factored. Does the rpm of the direct drive ratio to the diff match the motor rpm for optimum efficiency? Is the geared rpm better? Remember the transmission still has fixed gears, just a few to choose from. So now is direct or transmission ratio better for efficiency at 130km/h? Yes/no?
> 
> But also, what other conditions might you experience where the single diff ratio could be a compromise? Say climbing a 5% hill at 130km/h. Can the motor handle the increased power requirements for maybe a 10min climb (worst case example)? What about acceleration? Is 400nm torque enough? If the standard ice gave half this only briefly in the upper region of the power band and 3rd gear is nearest to twice the diff ratio then expect this level of acceleration with the fixed ratio. This is likely plenty anyway, and the traction calculations will tell you if it is too much. Also remember if you fit low resistance tyres you have alot less grip also so more power is no help or benefit anyway. Finally, what sort of cooling will your motor need to maintain these high current loads for longer periods? Remember with gears you need less power for the same acceleration as you have a mechanical advantage. And you may suffer higher overall average energy consumption with a single ratio but you save quite alot of weight which can either improve your efficiency or be offset by more batteries for increased range without the weight or space penalty. I think the benefit of having all batteries in the engine bay and a single motor in the transmission tunnel with no weight change or distribution is the optimum condition as few other vehicle modifications are needed then.


Thank you Tyler for plenty of information about that gear ratio issues. You summarized it very nicely to me, it makes quite complete list how to proceed when there are gear ratio issues. I have some experience with this kind of things and it always worked for me to try how bad it is at first (if possible), and then solve issues if there are some. I used to do homologation business at company which sold Russian cars at EU. Here we have swapped ancient petrol engines for turbodiesels, which often asked for gearing change. Sometimes it does, sometimes not at all. 
Please take in advance that I already have K11 linked with gearbox through quite expensive canev adaptor and it took considerable effort to make motor mounts. When I started this project, I was thinking using some reduction gearbox from 4x4 jeep-type vehicle to get 1:1 gear for normal driving (or slightly faster like 1:0,98) and 50% reduction gear for city driving and burnouts. I gave up these thoughts obviously and went for "gearbox style". Reading you guys I'm starting to think it was a mistake, but I'm convinced to continue the way that always worked - first I will try it how it already is and then I will figure out if there is a reason for changing the design. As soon as I would have to upgrade clutch, repair gearbox or actually ended with no usable gear ratio, then I will strongly consider direct drive.


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## mira9_cz (Feb 27, 2013)

Tyler said:


> So what is the optimum rpm for the motor at the given 288V rating of the motor?


I was planing to use K11 at 250V motor voltage, but to use battery pack voltage 288V. Not because of possible battery sag, but more because of Kostov recommended 250V and I simply have more cells then 250V. Soliton allows to set maximum motor voltage and unless I would desperately needed more RPM, I did not planned to mess with higher motor voltages. Is that a wrong approach? 



Duncan said:


> Hi
> No RX7 - just my "Device"
> 
> RX7's have a diff ratio of about 4:1 - very similar to my Subaru setup,
> ...


Thank you Duncan for concrete numbers you have provided, I have also checked your thread, very nice work! I always loved tube-framed racing cars. It makes sense to not even think about gearbox with 710 kg of weight.

I had not chance to weight Mazda without ICE, exhaust and other components, but I think (and hope) Skooler has these numbers, or at least I remember he weighted components that he removed and it is somewhere in his thread.

I found some gearing information about RX-8:

my mazda: 

gear 1:3,76:1
gear 2:2,27:1
gear 3:1,65:1
gear 4:1,19:1
gear 5:1,00:1
gear 6:0,84:1
REV gear:3,56:1
Differential:4,44:1
RPM at 120 km/h (theory):3.600 rpm

alternative less powerful model:

gear 1:3,48:1
gear 2:2,02:1
gear 3:1,48:1
gear 4:1,00:1
gear 5:0,76:1
REV gear :3,29:1
Differential:4,44:1
RPM at 120 km/h (theory):3.250 rpm

Do not know where "RPM at 120 km/h" came from and at which gear it is, but it is simple to find out when I will get wheel diameter inc. tire. 

I'm little bit puzzled from Kostov performance graphs availabe here: http://kostov-motors.com/tractionmo...)/seriesdcmotorsforelectricvehicles/k11alpha/


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## mira9_cz (Feb 27, 2013)

Here is the picture of the battery pack in current configuration -144V, 200Ah. This way it is installed in the silver van. There was actually one more 144V battery pack made from 90Ah Winston cells in the boxes beneath the vehicle, this is why the cells are in the plastic trays in cargo area


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## Duncan (Dec 8, 2008)

_I was planing to use K11 at 250V motor voltage, but to use battery pack voltage 288V. Not because of possible battery sag, but more because of Kostov recommended 250V and I simply have more cells then 250V. Soliton allows to set maximum motor voltage and unless I would desperately needed more RPM, I did not planned to mess with higher motor voltages. Is that a wrong approach?

_As I understand it_,
_The motor has a "resistance" - this is quite low maybe 15milliOhms
And the motor develops "Back EMF" dependent on speed and load

So when the motor is stationary 15v will drive 1000amps through it
At 2000rpm the back EMF will be ~ 50v so you will need 50 + 15 = 65v for 1000 amps
At 4000rpm the back EMF will be ~ 100v so you will need 100 + 15 = 115v for 1000 amps
At 6000rpm the back EMF will be ~ 150v so you will need 150 + 15 = 165v for 1000 amps

What this means is that the required voltage is entirely determined by the Rpm's and the commanded current

When you press on the pedal you alter a resistor or hall effect sensor to tell the controller how much current you want

Its microprocessor then sets up a mark space ratio to achieve the desired current

So you physically can't apply an excessive voltage unless you are overspeeding the motor

The advantage of a high voltage pack is that

pack voltage x battery current = motor voltage x motor current
So for any given Rpm/current the battery current is lower with a higher voltage pack

If you have a low voltage pack then you may have difficulty at higher revs,
My 144v pack would not enable me to reach 6000rpm, which is probably a good thing as I suspect the motor would blow up at 5000rpm


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## tylerwatts (Feb 9, 2012)

That is correct Duncan. 

Mira. You are fine running 250 motor volts with your 288V pack. As we said the Soliton will manage the difference and convert the excess voltage to useable current. So make it easier on the batteries or give more torque. 
You will learn alot keeping your transmission and probably find how much you use each gear and which is best suited to your performance needs. I'll point out the lower power 5 speed transmission ratios suit the EV better as the top gear is lower so less rpm or higher top speed. But your 6 speed is probably a stronger transmission so keep it. 
You have the recipe for a brilliant build so keep going with what you have.


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## tylerwatts (Feb 9, 2012)

Mira it is dougringham who's rx7 I was meaning. Check it out. 
Regards


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## mira9_cz (Feb 27, 2013)

Duncan said:


> [/I]As I understand it_,
> _The motor has a "resistance" - this is quite low maybe 15milliOhms
> And the motor develops "Back EMF" dependent on speed and load
> 
> ...





Tylerwatts said:


> Mira. You are fine running 250 motor volts with your 288V pack. As we said the Soliton will manage the difference and convert the excess voltage to useable current. So make it easier on the batteries or give more torque.


Thank you for your explanation guys. I think I understand the theory better now. Here is "Some preliminary info in the attached pic." from Mr. Plamen Nakev from "Kostov K11 Alpha?" thread, I think I can trust these data for now. 










Regarding this table K11 will reach it's RPM limit at 230V, 260A. 

Also Soliton allows to set up "Motor voltage" at block C: 










I think correct procedure will be to set up recommended 250V motor voltage limit and also set up RPM limiter to 6000 RPM, or slightly less from the beginning to be sure. I will see the results, then I can experiment with higher voltage.




Duncan said:


> So you physically can't apply an excessive voltage unless you are overspeeding the motor


I understand that as far as I will not go over 6000 RPM limit, the excess of voltage is not dangerous.


I actually sent an email to Mr. Plamen and I got the reply that matches with my careful approach: 
"Best option that will result in highest range is to use the Alpha. Limit motor voltage to 250V and rpm to 6000. (our partner www.rebbl.nl sells a converter that will make the sensor bearing compatible with Soliton). When you drive, aim for 3500-5500 motor rpm most of the time. This means to drive in second/third gear and shift up around 5000-5500rpm. Make sure you use thermal protection – this is the most popular fault cause. Indeed motor can withstand 1000A for 20sec but not if you do it 5 times in a limited time span."

However Mr. Plamen notified me about possible problem with Soliton Jr. Evnetics declares 340V maximum battery pack voltage. If I plan to do upper balancing to 3.6V, I should not switch on the system for a while and wait until voltage drops to 3.2V nominal. Then I should charge maximum to 3.54V (3.54 x 96 = 340V). Is this thinking correct? The best would be to contact Evnetics directly, but before I do, perhaps you guys have the experience as well. 
I planned to charge to 3.5V anyway, so it really does not matter. It is just that I always counted with the cell as 3V, not 3.2V or even charged state 3.5V and more.


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## mira9_cz (Feb 27, 2013)

tylerwatts said:


> Mira it is dougringham who's rx7 I was meaning. Check it out.
> Regards


Thank you for the tip! The only similar car I found what this one, but without any thread: http://www.evalbum.com/4476


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## Tesseract (Sep 27, 2008)

mira9_cz said:


> ...
> However Mr. Plamen notified me about possible problem with Soliton Jr. Evnetics declares 340V maximum battery pack voltage. If I plan to do upper balancing to 3.6V, I should not switch on the system for a while and wait until voltage drops to 3.2V nominal. Then I should charge maximum to 3.54V (3.54 x 96 = 340V). Is this thinking correct? The best would be to contact Evnetics directly, but before I do, perhaps you guys have the experience as well. ...


Evnetics here. 96 LFP cells is the absolute maximum you can run with a top-balancing scheme, and even then the Soliton controller will occasionally refuse to start up because of a "pack voltage too high" error. Don't expect a motor controller to measure pack voltage as accurately as a digital multimeter - typical error will be +/-2% (same with current and temperature).

Personally, I'd run 90 cells, mainly because it is not unusual for 2-3% of the cells to fail within the first year of use.


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## tylerwatts (Feb 9, 2012)

There you go Mira. The boss has spoken... run 90 cells, build a 12v pack from 4 cells and keep 2 spare. 
Your plans otherwise sound spot on. Good luck!


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## TrueSoft (Jul 23, 2013)

Great thread, just starting my conversion, keep posting.
good work


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## mira9_cz (Feb 27, 2013)

Hello guys, long time no update, but finally there is something to write about. Rear aluminum battery box is almost finished:



















As you can see, I had to make rear battery box made from two parts, because it would be impossible to put it into the car in one piece - not possible from bottom, nor from the top. Dimensions were measured good, there is almost no need for modifications. I will only order welding some protective bars to the bottom of the box, and also belly belt which I will mount to existing exhaust silencer holders.


















It is perhaps to deep, but it does not go under the bumper, so it should not be visible for people standing around the car. I'm able to fit 34 Wina 100Ah cells into it and in theory I can put some on the side above those 34 cells, but I do not plan to do this since I have lot of space under the hood (bonnet). 60x39x25 cm space under the hood is still unused if I will use 90 cells.


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## mira9_cz (Feb 27, 2013)

Tesseract said:


> Evnetics here. 96 LFP cells is the absolute maximum you can run with a top-balancing scheme, and even then the Soliton controller will occasionally refuse to start up because of a "pack voltage too high" error. Don't expect a motor controller to measure pack voltage as accurately as a digital multimeter - typical error will be +/-2% (same with current and temperature). Personally, I'd run 90 cells, mainly because it is not unusual for 2-3% of the cells to fail within the first year of use.


Hello Tessaract and thank you for your advice. I own 98 of Wina cells and I think it is understandable if I will try to put all of them into Mazda. As you said, some cells will probably die, but I think it is no problem to remove it as soon as I will "suspect" them from being not very healthy already. My plan is to charge to 3.4 - 3.45V / cell and therefore I hope Soliton should tolerate more cells. If it will show high voltage error, I will remove as many cells as needed. I hope I can not damage controller this way.


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## mira9_cz (Feb 27, 2013)

ScottyDont said:


> Looks good, do you have any photos of the fuel tank space and how much can fit in there?



Sorry, I know it took very long, but here is the picture. Problem is that it is hard to take pictures without flash when you are under the car at the workshop, because there is not very much sunlight. If you will take picture with the flash, it will ruin any depth that could be visible from the picture. So here it is, but me myself I can not imagine how deep this space really is :-/










My current plan is to put Soliton Jr. into this position, and as a cover I want to use original RX8 petrol tank. I will simply cut it to half and from both halves I will make boxes, into which Soliton and later possibly EMW charger will go. But this is just a thought, it depends if there will be acceptable access from the hole under rear seats.


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## tylerwatts (Feb 9, 2012)

You will need to get cooling into the tank also so remember this. Will you cool the controller?


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## mira9_cz (Feb 27, 2013)

tylerwatts said:


> You will need to get cooling into the tank also so remember this. Will you cool the controller?


Currently the controller is still installed in the van. There we experimented with Zalman computer cooler. The idea was to use CPU block with integrated pump, and the radiator supplied with the set. Advantage is that it runs on 12V, but later we realized that it is hard to tell what fluid to use to keep micro pump in CPU block lubricated. So we never finished this, but there was no reason to water-cool Soliton Jr. anyway, temperatures were always very reasonable all the time.










My plan is to use this small radiator from Zalman set together with 12V bosch pump from some car water heater that I already have. Idea is to keep only the bottom of the tank, because it is shaped to cover whole space where tank used to be. This I think should shield Soliton from dirt and salt from the road, but also should not completely block access to some cool air.
The radiator I will place somewhere where I will be sure of enough air-flow, but to keep it from dirt as much as possible.


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## tylerwatts (Feb 9, 2012)

Ok that sounds good. Just remember, if air can reach the controller then dirt will definitely get there also! I would personally try to seal it with rubber seals, like car door seals. And then cooling will keep the controller temperature safe. My personal preferance though. I look forward to your progress and execution of this idea. I also want to mount a controller in place of my fuel tank but am very concerned about dirt and damage.


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## Roderick (Dec 8, 2013)

Just caught up with your build thread! 
I was thinking of making similar setup K11 alpha+sol1 with rx8 until I found only little more expensive donor car  
How's your build going?


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## mira9_cz (Feb 27, 2013)

Roderick said:


> Just caught up with your build thread!
> I was thinking of making similar setup K11 alpha+sol1 with rx8 until I found only little more expensive donor car
> How's your build going?


Hello Roderick. What donor car have you eventually found? 


I actually have some news. I have decided to not mount Soliton Jr. at the place where petrol tank used to be, mainly because of length of the motor cables. I'm really going out of space at Mazda, but I managed to find the spot at the firewall, check the picture below. It is necessary to move brake line a little bit.










I remember Soliton Jr. manual saying that four M6 screws to the firewall sure is not the good idea. I have actually used one original M6 screw that was already at the firewall. Second screw I had to drill into the Mazda body, but two lower Soliton mounting spots are firmly screwed to the aluminum holders mounted to Mazda integrated chassis. This should be enough. There was not enough space to take pictures, I will try to picture the bottom holders when I will have controller removed again.

With new position of controller I had to remeasure possible maximum sizes of front battery boxes. There will be 4 boxes under the hood:










26 cells here, this box will be mounted behind front bumper, I will not have access to cells located here because another battery box will be at the top of this one 










13 cells, this one is right next to the controller










13 cells, this one goes into the middle of the space under the hood










Front battery box will be right above the first pictured box. 12 cells left will go there and very little space left for contactor or something.

I hope battery boxes will be ready soon, in next "round" I will try to put them into Mazda and design some holder for them. 

Unfortunately I do not have any reasonable space left for 12V board battery and with DC/DC issue not yet solved this wakes me up in the night. Truth is that I still count with 98 cells, which will probably mess with Soliton Jr. max voltage. If I will end up with 90 cells as Tessaract supposes, I will have enough space for board battery in front battery box. 
If not, alternative locations for board battery are the space where tank used to be, or I will use four LifePo4 (well they say LiFeMnPO4) GBS200Ah cells that I already have (http://www.electricautosports.com/node/330) and mount them somehow into rear battery box above 34 traction cells that will be accommodated here.

As you can see I have lot to think of. If you have some good advice where to put the 12V board battery, feel free to express it


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## Roderick (Dec 8, 2013)

mira9_cz said:


> Hello Roderick. What donor car have you eventually found?


I've managed to find Jaguar xk8(96') for 7kUSD with free Vehicle inspection (last 2 years). and newly painted body!
the only things im concerned with it is that I cant inspect it till I buy them (its a long way away from where I am...(they said they'll send it to me for free!))

Edit: The car has done 130,000km!


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## palmer_md (Jul 22, 2011)

nice project. Cant wait to see the finished product.


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## mira9_cz (Feb 27, 2013)

Roderick said:


> I've managed to find Jaguar xk8(96') for 7kUSD with free Vehicle inspection (last 2 years). and newly painted body!
> the only things im concerned with it is that I cant inspect it till I buy them (its a long way away from where I am...(they said they'll send it to me for free!))
> 
> Edit: The car has done 130,000km!


XK8 is beautiful car, I think Rebbl has some conversion kit done for this car, including homologation I guess.


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## mira9_cz (Feb 27, 2013)

So I received rear battery box with holders and reinforcement welded. When guys heard that there will be 100 kg of batteries in it, they did little bit overkill reinforcement in my opinion, but I like it. The stronger the better, right?



















Also front battery box number 1 prototype is ready and I also managed to measure what holders to weld at it and where exactly. I hope it will be ready soon.


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## mira9_cz (Feb 27, 2013)

There is one more news. I have decided to buy BMS, not very proud of it, but here it is. 

As you may have noticed from my photos posted before, I have one half of battery pack from different series of Wina 100Ah cells then the other half. Unfortunately between old and new series they have changed terminals to new version:










More details here: Wina cells terminal modification

I plan to go with top level balancing scheme, but if I would later found out that I will need some balancing because of different terminals, it will save me lot of work with installation.

So basically I would like to have BMS only for SOC monitoring purposes and charger control. I hope I will be able to reach positive DOD at the route I need to travel, allowing me to charge the cells only to 3.4 - 3.45 V WITHOUT lowering the current at the final stage - simply stop charging when first cell will reach 3.45 V. This way I hope I will not use balancing function of BMS at all, even with the issue with different terminals at the half of the cells.

My friend uses successfully Winston 160Ah, Sinopoly 200Ah and Calb 180Ah cells mixed together in his Fiat 126 electric, without BMS, charging the way I described above without any troubles and without cells going out of balance. So I guess I should be fine with my different terminals at Winas 

I think I will go for BMS123 - BMS123 at ev-power.eu and BMS123 at GWL-Blog
I like this BMS, it is very simple to connect and to control, reasonable priced and it just does what it should do. The only function I'm missing the possibility to see voltages of individual cells, only MIN and MAX is available. On the other hand Elcon charger control is present, which could come handy and this I consider to be the biggest advantage and the strongest reason for me to buy BMS123.


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## mira9_cz (Feb 27, 2013)

Perhaps I could explain why I consider possibility to control Elcon charger so important, that I'm willing to spend over thousand EUR for BMS123 and one hundred of balancing modules for the cells.

It sounds stupid to me too actually, but I take this homologation and registration stuff seriously. Part of EHK100 E.V.-general legislative is that you have to have on-board charger and you must pass EMC test with it. I would really like to go with EMW open source charger, but since it is not insulated it can not pass possible EHK100 inspection. On the top of it I know that the charger EMC emissions are usually worse then E.V. EMC noise and you can no do much with it.
If the bureau will tell me to pass EMC test with DEKRA (which I expect they will) the Elcon is the cheapest way how to pass the tests - as much as I heard they can do well, and rebbl (I think, but there sure was somebody) has it EMC-certified already for the worst case if DEKRA measurement tests would go badly. 

Stupid bureaucracy. We Czech nation are very resourceful. Our people read the law in their own way, seeking for any chance to go though it with advantage. This is why we have one of the best thieves in history  Anyway this also is the reason why all officers are scared to allow anything unusual (like E.V.). But I'm sure all traffic bureau officers all over the world are bastards, this just comes with the job, right? ;-)


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## mira9_cz (Feb 27, 2013)

Small update: Two of four front battery boxes are ready. Not much to see, but here is photo from the progress.










Except this I'm successfully controlling RX-8 gauges with CANbus. I managed to operate RPM meter, speedometer, temperature meter, but the rest I have troubles with. Lubrication gauge seems to operate in only two positions - no oil pressure and some oil pressure. This seems weird to me, is is probably my mistake. Second trouble I have is that all MILs are not working, except Merry-Go-Round icon and SRS airbag. SRS is not controlled by CAN and Merry-Go-Round I can control with CAN messages.

Here some guy did a splendid job which helped me a lot at the beginnings:

http://www.cantanko.com/rx-8/reverse-engineering-the-rx-8s-instrument-cluster-part-one/comment-page-1/#comment-42186

I want to develop simple board, which will convert Kostov K11 temperature signal and RPM speed to CAN and send the data to instrument panel. Unfortunately ECU will keep sending it's own messages and these might interfere.


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## mira9_cz (Feb 27, 2013)

Here is the video. There I'm just "replaying" some data that I have recorded at my friends Mazda with Wankel still inside. 

http://youtu.be/16MwsHVcl1g

And here is the video with gauges start. This I have sended to the cantanko guy - it feels strange to me why all MILs don't go ON when the panel goes ON, as the cantanko guy describes in his article: https://www.youtube.com/watch?v=L2xahfruq-I


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## mira9_cz (Feb 27, 2013)

Lot of work done lately, so here is an update.

- I have delayed playing with CAN Bus since the instrument panel I have borrowed from RX8 guy is defective. He promised me another panel that does not actually come from car that burned as this one, but there was no time to meet him. 

- I have all battery boxes done and paid. 5 battery boxes welded from alloy plate cost me 900 EUR in material and welders work. Could be done for much less in metal, but oh my god these boxes are so much lighter then you expect when you are lifting them!  Top covers I will do later.

- Clutch hydraulic line was shortened, with no ICE in the way it was possible to lead the line better to save space. You can notice this at the first picture below.

- 64 100Ah cells in the front is quite a lot of weight, so it felt appropriate to enforce the original bar which was before supporting radiator, starting battery and some other components. It will not be visible because 3 battery boxes will be sitting at it and one will be partially hanging from it.










- With front battery boxes holders finished it was time to continue working at the rear of the car. Before it will be possible to install rear battery box (carrying 34 Wina 100Ah cells), rear stabilizer had to be modified. 










I considered mounting the stabilizer to the battery box, but since stabilizer is moving part (not much but still it is) and the rear battery box will be firmly fixed with the body, I have decided not to risk anything. Eventually we had just moved the original mounting points down using quite tough aluminum profile, and rotated the stabilizer upside down. The middle part is still higher from the ground then the bottom of the spine that goes from transmission to differential case.

- There was no time to mount the rear battery box yet, but here is about how it will look like:











What will follow:

- rear battery box installing
- routing and shielding power cables, installing front battery boxes
- vacuum pump connecting, vacuum switch installation


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## mira9_cz (Feb 27, 2013)

I also have one question for you guys, if there is still someone patient enough to watch my slow and random progress.. 

Is there some reason why not to use this cable for connecting the batteries? It is some "Zealum 50 mm2 Peak Current Power Cable" for car audio application, that was used to power some kind of subwoofer in the trunk of my Mazda before I had bought it. 










I would like to connect rear battery box with front battery boxes and Soliton controller utilizing this audio cable. There was 10 meters of it inside the Mazda! It might be good motor cable too. Is it bad idea? I think it should be more then thick enough, but isn't the fact that it was originally determined for audio application some problem?


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## wav (Nov 21, 2010)

Hi Mira,
just read through this thread. Great to see a Kostov in a build.

Re audio cable, this would typically be made of what we call E-Cu. This is high purity copper that offers a higher conductivity. So as far as the conductor is concerned, you have the best choice. The insulation is another matter. You should have some spec printed on the sleeve. But if the cross section is right, I would not hesitate to use it

At the start, you mentioned that you would be looking at an AC set-up and had chosen DC because of cost. Is there a big difference when using a Kostov 11?


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## dougingraham (Jul 26, 2011)

mira9_cz said:


> Is there some reason why not to use this cable for connecting the batteries? It is some "Zealum 50 mm2 Peak Current Power Cable" for car audio application, that was used to power some kind of subwoofer in the trunk of my Mazda before I had bought it.
> 
> 
> 
> ...


50 sqmm is about the same as 1/0 awg cable. I would not hesitate to use 50 sqmm cable between the battery boxes and the motor controller. However this cable may not be insulated well enough to handle the traction pack voltage. A car audio amp that could do 2500 watts into a 4 ohm speaker would need to be rated for 100 volts. See if there is an insulation rating that would let you get to your traction pack value. With high voltage cables it is a good idea to make them orange so the emergency services people don't kill themselves trying to extract you from the vehicle when they cut through the cables.

So color and insulation rating are the only real issues with using this cable.


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## mira9_cz (Feb 27, 2013)

Thank you guys for good advice. I will make them orange of course, or to put them into something painted orange. 

Regarding insulation I will check if there is some rating, but I did not see any last time. Perhaps I might put them into shrink tape to make things better? 

Because of my concern for EMC noise I would put these cables both twisted inside stainless steel flexible canal. Or maybe I will use shielded hose, so the cables will be protected enough. I was even thinking putting the twisted pair of power cables from the rear battery box inside separate shielding (like the one used at shielded hose), but I don't know if this is meaningless if these cables will be inside of grounded shielded hose/flexible canal anyway.


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## mira9_cz (Feb 27, 2013)

wav said:


> At the start, you mentioned that you would be looking at an AC set-up and had chosen DC because of cost. Is there a big difference when using a Kostov 11?


Thank you. About your question, I was always aiming for powerful conversion and RX8 is quite heavy. This situation usually leads to DC setup, because there is not many high power AC components at the market, so you must double the motors, double the controllers and this gets expensive. Well at least this I had taken from threads I had read over the time. Also truth is that I knew that there will be opportunity to buy slightly used LiFePo4 cells and Soliton Jr. for very good price in few months. So I risked it and ordered K11 Alpha, hoping that the deal will happen.


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## wav (Nov 21, 2010)

Hi Mira, yes I can see the advantage if you had to double up. It is true that in Europe, high power ac or bldc drives are not so available or too costly. But like you, I have not managed to find a used DC motor locally. I am from Malta, so the choice is less. I want to convert a C4, and we have steep hills on this island. So I need a torquey motor.

Anyway, thanks for replying back. Keep posting.


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## mira9_cz (Feb 27, 2013)

wav said:


> I want to convert a C4, and we have steep hills on this island. So I need a torquey motor.


You mean Corvette C4 or Citroen C4? I have Kostov K9 144V which I don't need, so I guess it might be for sale. But then your reply would have to be Citroen, not the Corvette ;-)


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## wav (Nov 21, 2010)

Hi Mira, 
it's a Citroen C4, hmmm very tempting. K9 might work with gearbox. I did consider this motor, but I considered it to be on the minimal side for my application. Is it a sepex or series?


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## mira9_cz (Feb 27, 2013)

wav said:


> Hi Mira,
> it's a Citroen C4, hmmm very tempting. K9 might work with gearbox. I did consider this motor, but I considered it to be on the minimal side for my application. Is it a sepex or series?


It is series excited motor with possibility of parallel field switching. 
What a pity, Corvette C4 was my first choice for conversion and I would love to see somebody do it. Problem is that Vette suspension is too hard to use her daily, so I continue driving her E85 Ethanol and for electric project I bought the RX-8. 
Why the hell Citroen C4? As Skooler once written in hid thread, if you must spend thousands of EUR for electric components, it is good to put them into something worth it. Citroen C4 will get old and worthless very soon.


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## mira9_cz (Feb 27, 2013)

Today we managed to prepare cable loom leading from rear battery box to the space under the bonnet. Below you can see all cables that I decided to put into the shielding. The shielding will eventually be painted bright orange to meet regulations. 











There are main power cables, which I had decided to put into shrink tube to feel better about the insulation. I did not twisted them though, I believe shielding will serve good enough against EMC emissions. Thick red and blue cables are 12V+ and 12V- from the board battery located in the boot. Black ones are leads for contactor coil. I'm still not sure if DC/DC converter and charger can be permanently connected to traction voltage, so I guess pair or 4 mm2 cables will not cause any harm being there. Second red thick cable is extension of one of the charger leads by the reason that with soliton off traction circuit keeps opened. With charger in the back of the car and controller under the hood I see no other option. Eventually I decided to put also pair of 2,5 mm2 cables just as spare ones, for example or for coil of second contactor. These are not at the picture.











Here you can see the test of length of the main cable loom inside the shielding already. It will eventually lead different way, but it will look similar to this.


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## steelneck (Apr 19, 2013)

Why do most route their cables underneath the car? I see some reliability issues with that, like sharp stones being thrown from the tires or driving over some object causing damage to them. Why not route them close to the tunnel inside the car, there they are way more protected betwwen sound dampening material and the floor carpet.

If there is some regulation issue that it must be easy to spot where the cables are, i think some mark up on the floor carpet is even better than they just being orange. Underneath the car they will get dirty or even embeded in snow and ice winter time.


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## skooler (Mar 26, 2011)

steelneck said:


> Why do most route their cables underneath the car?


Because most would rather something went wrong outside the passenger cabin.

FWIW. I use double insulated cable and then thick conduit underneath the car following the original exhaust route.

As long as the cabling is in the tunnel then there is no risk of it being caught by speed bumps, bottoming out etc.

HV+ and HV- are never in the same conduit.

If routing inside the car the chances are you would follow the sill line (under the doors). Firstly, this is potentially a safety issue if the 'jaws of life' are required (see sticky on emergency responder warnings).

Secondly, have you ever tried to add cabling inside the cockpit. I have done it with several 4 guage (16mmsq) audio installations and thats normally a pain in the ass, no space, carpets dont fit again etc. Cant imagine trying to do it with two 50mmsq+ double insulated cables!! 

Not to mention that traction cables should be as close to eachother as possible (ideally twisted togethor) to reduce EMI. Inside tbe cabin that's a lot of required space. In the tunnel there's already plenty of space.

Finally, would you want the traction cables running in parallel with the 12v loom? I dread to think what interference would be caused!


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## steelneck (Apr 19, 2013)

skooler said:


> If routing inside the car the chances are you would follow the sill line (under the doors). Firstly, this is potentially a safety issue if the 'jaws of life' are required (see sticky on emergency responder warnings).
> 
> Secondly, have you ever tried to add cabling inside the cockpit. I have done it with several 4 guage (16mmsq) audio installations and thats normally a pain in the ass, no space, carpets dont fit again etc. Cant imagine trying to do it with two 50mmsq+ double insulated cables!!
> 
> ...


All good points skooler, though I have just routed my 70mmsq on the inside, following the right side of the tunnel, some cm up on it actually. All my 12V from front to rear follow the left side sill line. My first thought was to do it like everyone else, but when i was under the car i simply could not find room for my cables in the tunnel behind the gearbox, it is very narrow along the drive shaft and do not open up until the diff. So if i had put them underneath, then i would have been forced to run them under the doors. Inside i have plenty of room and they will hardly be noticed. But i am thinking about making some cover over them before i put the interior back.


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## skooler (Mar 26, 2011)

steelneck said:


> All good points skooler, though I have just routed my 70mmsq on the inside, following the right side of the tunnel, some cm up on it actually. All my 12V from front to rear follow the left side sill line. My first thought was to do it like everyone else, but when i was under the car i simply could not find room for my cables in the tunnel behind the gearbox, it is very narrow along the drive shaft and do not open up until the diff. So if i had put them underneath, then i would have been forced to run them under the doors. Inside i have plenty of room and they will hardly be noticed. But i am thinking about making some cover over them before i put the interior back.


Happy it worked well for you. The car is probably the biggest influencer in making this decision.


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## mira9_cz (Feb 27, 2013)

steelneck said:


> Why do most route their cables underneath the car?


I remember Sigmadrive controller manual advising that traction cables should be led as low as possible to prevent EMC emissions. The higher the cables are, they act more like an antenna. So I put them under the car. They will go parallel with the spine which goes from gearbox to rear diff, I'm not really afraid of damage.


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## mira9_cz (Feb 27, 2013)

skooler said:


> Finally, would you want the traction cables running in parallel with the 12v loom? I dread to think what interference would be caused!


This is what I'm on the other hand afraid a lot, but I'm missing experience there, so I decided to risk a little and try what will happen. If the EMC noise will be significant, I can always lead another two cables from the battery.


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## dougingraham (Jul 26, 2011)

I twisted my 2/0 cables from the rear battery box to the front of the car and ran them forward using the original exhaust hanger mount points. They are the orange welding cable and at each hanger point I reinforced the cable with 3 inches of heat shrink to spread out the load and used the 120 lb weather resistant zip ties intended for this kind of thing. Been driving it almost 4000 miles now like this and I have inspected them a couple of times and there doesn't appear to be any issues with running them this way.


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## steelneck (Apr 19, 2013)

I hope the OP do not mind this, i am not trying to hijack the thread. skooler, you got me thinking. If something happens to the HV cables, it is better that it happens outside of the cabin, but on the other hand, the odds for it to actually happen, is greater on the outside. So how to square this circle? This made me come up with an idea, that feels better the more i think of it, it's very simple too. Put back part of the exhaust pipes, replace any muffler with a pipe and route the cables through those, they get just as protected and they are out of the cabin. For me this would still be quite simple to do since i have not put my interior back and my cables are not permanently in place. I think i will do this. You are very welcome with any opinions on this over at my build thread (to not hijack this one further). Just made a post about this.


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## mira9_cz (Feb 27, 2013)

Steelneck do not worry, I don't mind about hijacking the thread. I think you are too much worried about damaging the cables under the car. There is very low chance that this might happen and if it would happen then it would be during some kind of accident where you can expect troubles to happen anyway.
By the way there are fuel lines under the car just in metal tube without any protection around. The same with fuel tank - it is under the car and made from plastic. 

My idea was to use aluminum tube as a tunnel for cable and put it instead of exhaust as you proposed, but then I decided to use the flexible shielding. Level of protection will be about the same, but the weight difference is significant.


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## mira9_cz (Feb 27, 2013)

This week my new DC-DC converter arrived. It is 1500W Meanwell unit with 15V DC output, adjustable from 13.8V. 12V output version of this power source is adjustable to maximum 13.5V, which is not enough to charge 4 cell LiFePo4 board battery. I had found a guy who was selling four slightly used RSP-1500-15 units. He sold me one for 160 EUR shipped from Germany to Czech Republic. If you want, I can give you contact to this guy, the price is very good, perhaps he still have some.

http://www.meanwell.com/search/RSP-1500/RSP-1500-spec.pdf


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## z_power (Dec 17, 2011)

Hi Mira,
I use 12V version of the same "brick"; you're right about upper limit of voltage as long as trimpot is used for setting. There's also possibility to set Vout with reference voltage applied to one of pins, very simple circuit containg voltage source and resistor divider does the trick - allows up to 20% "overvolting" 
I suggest you to use relay on output side to prevent aux battery drain when device is off; an inductor on supply side was already mentioned here in the forums.
To reduce dust and humidity I mounted mine inside the cabin, needed to change cooling fan to less noisy one. No worries about HV in passengers compartment, already have battery boxes in place of rear seat 
Michal


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## mira9_cz (Feb 27, 2013)

Thank you Michal for input. 

>>>an inductor on supply side was already mentioned here in the forums.

This I must check. I do not know what specification such an inductor should meet for currents of my DC-DC. I will try to search some info here at forums as you suggested.


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## mira9_cz (Feb 27, 2013)

I found two days to continue working at traction cables. As people there suggested, I kept only traction voltage cables in shielded loom. So only four wires remained, two wires for connection between front and rear battery box and second pair is for charger and DC-DC. 

This is how rear battery box came out. It is ready for cells installation now.










I decided to put shielded loom with traction voltage cables to passengers side of the car. This is final position. I will eventually spray the loom bright orange. I had considered plastidip, it might be good to prevent the shielding from corrosion (I'm quite not sure what metal my shielding is made of). 










This is how nicely I managed to secure shielding to battery boxes - input and output picture. I think this came out well and both ends of the shielding will be grounded securely.


















I'm not quite satisfied with this way of leading the shielded loom under the motor, but it appeared to be the only option to keep the rest of the connections between front battery boxes short and parallel as much as possible. 










Another succeeded step is the front-bottom battery box. It is finished and in position. Traction cables with well crimpled connectors are leading out of the shielding inside of it, so it is ready for cells installation as well. 










The last success of past two weeks is that we managed to run the motor for the first time. It was running about and hour continually. Below is the picture of how it should be connected in Mazda with respect to its position at the picture - output shaft is at the left side.










I must say that I think my K11 Alpha is not very well balanced. Flywheel is machined and balanced precisely, so the motor is the only one the suspect with no gear shifted at the gearbox. My only other experience with similar DC motor is with Kostov K9 and I must say K11 I find noisier. You can hear that the sound of motor changes a little bit at the same time of each rotation. Also if you touch the car practically anywhere, you can feel vibrations in the same frequency as the motor sound. I remind that I kept original silent-blocs for Kostov motor holders. 
I will continue with motor run-in at 12V, we will see how much it will improve. I think both noise and vibrations will disappear at higher RPMs, but still.. I tried to film the video, but I did not managed to capture the noise. I will try again later as soon as I will get the chance.


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## mira9_cz (Feb 27, 2013)

Also I'm not sure what is the exact purpose of those two pairs of thin wires at the motor - you can see them at the picture just above in previous post. At K9 I had only one pair and these were the thermistor wires. 

From the only support PDF I managed to find for K11 Aplha (available here: 
http://kostov-motors.com/tractionmo...)/seriesdcmotorsforelectricvehicles/k11alpha/ ) As far as I understand is that the white pair is from internal thermistor, and the yellow pair is "thermal sensor (normal open)". Well I'm not sure what is the difference here, but my guess is that the yellow wire is thermal switch for possible relay connection (opened when temp-ok, short when hot and fans should come on), and the white pair is to take resistance value in ohms to know the temperature.

I also hope there is the same thermistor inside K11 as is inside of K9 (KTY84/150). When I asked Mr. Plamen, he just sent me the link to this drawing pdf, but I can not see this information anywhere in this document


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## steelneck (Apr 19, 2013)

mira9_cz said:


> I had considered plastidip, it might be good to prevent the shielding from corrosion (I'm quite not sure what metal my shielding is made of).


If you are talking about the braided hose/strap it is usually made of tinned copper.
Probably the same as i used to make battery interconnects of:


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## skooler (Mar 26, 2011)

mira9_cz said:


> Also I'm not sure what is the exact purpose of those two pairs of thin wires at the motor - you can see them at the picture just above in previous post. At K9 I had only one pair and these were the thermistor wires.
> 
> From the only support PDF I managed to find for K11 Aplha (available here:
> http://kostov-motors.com/tractionmo...)/seriesdcmotorsforelectricvehicles/k11alpha/ ) As far as I understand is that the white pair is from internal thermistor, and the yellow pair is "thermal sensor (normal open)". Well I'm not sure what is the difference here, but my guess is that the yellow wire is thermal switch for possible relay connection (opened when temp-ok, short when hot and fans should come on), and the white pair is to take resistance value in ohms to know the temperature.
> ...



One is a thermistor and one is a thermal switch. Simply wire the switch to a relay (coil side) and then use the switched output on the relay to turn the fan on and off.

For what it is worth I swapped the standard relay to a 30s delay relay so that the fan stays on to cool the motor for a little after the switch opens. This stops the motor cooling getting into a state of hysterisis.

I use a very similar settup for ny vacuum brake setup.


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## mira9_cz (Feb 27, 2013)

steelneck said:


> If you are talking about the braided hose/strap it is usually made of tinned copper.
> Probably the same as i used to make battery interconnects of,


Hello, yes, I think it will be this one. I checked before and I could not see orange color when I cut strap, but when I checked closer, it sure is orange. So copper it is. I was affraid that I bought some iron shielding. Anyway I think plastidip is still worth considering, instead of just orange paint in spray.. 



Skooler said:


> One is a thermistor and one is a thermal switch. Simply wire the switch to a relay (coil side) and then use the switched output on the relay to turn the fan on and off. For what it is worth I swapped the standard relay to a 30s delay relay so that the fan stays on to cool the motor for a little after the switch opens. This stops the motor cooling getting into a state of hysterisis. I use a very similar settup for ny vacuum brake setup.


Hello Mike, thank you for input. If I remember correctly, you cool the motor together with Soliton controller, right? Well I also considered this option, but in my experience with Soliton Jr. plus K9 in small van the motor needs more cooling, then the controller. Relay with 30s delay is good idea! 

GWL Power developed this prototype board, which collects temperature from thermal sensor of Kostov motor and switches the output 12V when temperature reaches 60 C degrees, and another output at 120C degrees.
This board I'm using at Mazda, but because the output is only 20mA capable (the coil of classic automotive relay would burn this output), I must have very expensive semiconductor relay, switching original relay (I think COOLING FAN1 RELAY). So thank you very much for telling me that thermistor does basically the same thing as my GWL prototype board plus semiconductor relay, but better! Anyway I already installed everything, so I will check at which temperature thermistor inside Alpha switches and if it will be sooner or about 60C degrees, I will reconnect it. Thank you once more, sometimes I hate myself


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## mira9_cz (Feb 27, 2013)

OK, so I spent 4 more working days at Mazda and I managed to finish following:

- Soliton controller is connected (+15 behind COOLING FAN 2 relay, brake signal from ABS and throttle signal from the cable loom near front left wheel)
- Vacuum pump (+15 behind COOLING FAN 1 relay through vacuum switch)
- BMS (just prepared wires for it - +30 behind fuel pump fuse, +15 behind main relay, cables for "fuel" gauge taken from the original fuel tank wires)
- motor cooling (+30 from main relay through fuel pump relay 1 supply through semiconductor relay and temperature reactive board)
- controller cooling (just prepared wires for it - fuel pump relay 2 switched by soliton controller)
- DC-DC contactor (behind EGI COMP1 fuse, which is switched by main relay, so +15)
- Rebbl motor RPM signal divider (powered from SGND and S12V from soliton)

As soon as I will find some free time, I plan to draw new schematics directly into original Mazda electric manual. But I guess it will take some time.

Today we managed to rotate the rear wheels at 24V with the controller. Everything seems to be o.k., so next time I hope first cells are going in!


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## mira9_cz (Feb 27, 2013)

And here are some pictures, although I think these are not very fun to watch..


There is a picture of all the 12V cables related with controller, BMS, vacuum pump, cooling and other components leading from original fuse box, prepared to be be connected to appliances.










Eventually it will of course look like this, but I will do the finishing after I will put the battery boxes in. 










Here is the final connection of the motor. 










Also the mistake at Rebbl's stole 2 hours of searching for what is wrong with RPM signal. It is my fault, I might notice when I soldered the resistor to the board. Below you can see that GND is labeled as +12V input and vice versa. The back of the board is GND everywhere where is are not routes from the chips.


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## mira9_cz (Feb 27, 2013)

As far as now I can say I have everything what I need for test drive, except battery pack in the car. Soliton is working very well, all electrics is connected or prepared for future connection, so I started with the batteries. 

As you can see I started with rear battery pack, this one is the less difficult to build. As an heat insulation I had used foam material which was originally packed with the cells in wooden box when they came from China. So it should not burn like hell in case of accident I guess  










Here you can see how 34 cell WINA 100Ah battery pack looks like in the trunk of Mazda RX8. I can safely tell that it is not possible to fit more cells here, at least not if they stand vertically as they should. I think you can notice that there is missing connection before two rows. There I will add cable with connector as a "safety switch", which I will easily reach and disconnect when I will need to perform some job at traction circuit.
The balancing modules at the top of the cells are BMS123.










I managed to put the cells inside of the front-bottom box already as well, here is the picture of how it looked like in the process. This battery box is designed to carry 26 cells. However there will be only 24 of them, the experienced ones know why (or smart ones who draws pictures first and then order welding job..) 










The BMS main controller unit I decided to place at the top of the box where original ECU seats in. It might look little bit "rude" for such a component to be located, but as soon as battery boxes will be in I hope it will look o.k. 


The last job of the day was the vacuum pump hoses connection. I used vacuum reservoir from Ford Aerostar van. Eventually I will switch it for GM spherical vacuum reservoir, but I could not find it and this Ford one was the only one in reach. 










That is all for now. Tomorrow I can afford to spend whole day with Mazda. I plan to connect BMS balancing modules with BMS Main controller unit in each battery box separately. That way I will be sure everything is all right and working well even before I will put other cells in (and make access to many possibly malfunctioning balancing modules impossible).


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## mira9_cz (Feb 27, 2013)

Front-bottom battery box is completed. 24 cells inside, BMS working, I even used the CAN-bus special cable for BMS and grounded the shielding at the ends of the cables inside the box. 




















The lid (top of the box) is in place. I wanted to make it from aluminum as the rest of the boxes, but eventually I tried something new. The material I'm testing is cuprextite. The side with copper should do the same shielding job as the aluminum, but the bottom of the lid is still non-conductive. What do you think?











With bottom battery box finished and in final position i little bit relocated power steering cables and continued in putting cells into battery boxes. One of three remaining I managed to finish as well.


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## mira9_cz (Feb 27, 2013)

And little summary what is yet to finish. 

stage 1:

- put the rest of the cells in and mount balancing modules on them, make BMS work
- trace fuel gauge cables from under rear seats to BMS
- set-up the controller
- put 12V battery in place, work-out holders for it
- mount the water cooling pump for controller, make holders, connect hoses, possible expansion tank need
- put some lids to other battery boxes, even temporary ones just against the mess from the road
- put 12V board battery charger and traction battery charger into the trunk
- check the gearbox oil


stage 2: 

- some CANbus stuff to make power steering work and instrument panel show what it should to pass possible EHK100 inspection.
- think of some place for DC-DC and put it there.
- add. switching contactor between charger and DC (they use the same cables with traction voltage) 
- place the charger instead of original fuel tank.

stage 3:

- I really like ZEVA fuel gauge as Skooler has. I think I will mess with the cells to get them balanced a lot, which will ruin my BMS123 SOC gauge every time. ZEVA seems to be perfect solution for to be independent on BMS. 
- tablet instead of gps LCD to run BMS and soliton readings

I will start driving and testing somewhere between first and second stage. Between Stage 2 and Stage 3 I hope I will be ready to apply for homologation.


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## mira9_cz (Feb 27, 2013)

Next complete day of working at Mazda brought following results:

Rear battery box is finished. Traction cables connected, BMS working, protective plastic caps fit at battery screws...










... and the support for 12V battery in place:


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## mira9_cz (Feb 27, 2013)

Also 12V board battery is in place, it is the green flat thing. These are four GBS 200Ah LiFePo4 cells which I already owned before my Mazda project and now I can finally utilize them.

GWL Power tested the GBS cells and decided not to sell them at ev-power.eu, because of poor quality. 

At the link below you can see comparison test of GBS 100Ah LifePo4 cells with Wina 100AH LiFePo4 cells, those which I use as traction battery. As you can see, GBS cells results are miserable. 

http://gwl-power.tumblr.com/post/42917589464/is-there-a-difference-between-100ah-and-100ah

On the other hand Wina cells results are the top of the class! 

I must say I'm very well aware that 200Ah 12V board battery is overkill and really really unnecessary. The weight is considerably high, but on the other hand the space where it seats would be unused anyway. Any other 12V board battery would take space from me somewhere else, where I need it.











Perhaps I will be able to go without DC-DC at all, because of the capacity of my board battery. Electric power steering sure consumes a lot of power though, so this is something I will have to test.


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## mira9_cz (Feb 27, 2013)

For those not familiar with the shape of GBS cells chassis here are some picture from build, and also some details of them sitting in the car. 

You can notice that I connected Plus poles of all cells and Minus pole by 2.5mm cables for effective top level balancing from time to time, so I would not have to remove the battery from the car. Also good connection point for CellLog to see the voltage of the cells.


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## mira9_cz (Feb 27, 2013)

Today I also experienced very weird observation. I must say I'm not sure what it is, I suspect defective cell, but how? PLEASE HELP. 

It started like this: I received weak electric shock when I tried to connect rear battery box. I said what the hell and then I measured 80V between vehicle chassis and the wire I tried to connect!!! I was holding traction voltage cable, connected to + pole of front battery boxes. For now I have only two of them connected in series. So I supposed I let their output traction cable touching the Mazda somewhere. But nothing, there was no output cable, connected to the last cell! Everything safe. 

80V is the voltage of just the bottom battery box, so eventually I was able to measure through the traction battery pack to the cell at which I could measure only about 3.2 between it's plus pole and vehicle chassis. This was the + pole of the last cell in bottom battery box, so also a minus pole of the first cell of top-front battery box. So I said myself all right, the shielding of the cable connecting both battery boxes must be touching the cells poles somewhere. BUT IT WAS NOT. 

After long search for mistake I desperately disconnected both cells in suspicion from the rest of the traction cells. And the parasitic voltage 1.5V was still present there between plus pole of one of them and the vehicle chassis!! How?! You can imagine myself looking like idiot at the multimeter readings, watching the cell with both plus and minus terminals free of connection to anything, but still reading stable 1.5V between free plus pole and the vehicle chassis!!!! Me myself I was touching the cell with nothing else then multimeter wire tip, and also not touching the vehicle itself, wearing the shoes, so I suppose nothing could go through me.

I carefully checked every square millimeter of the cell which appeared to be supernatural and there was no damage anywhere. So, desperate and unable of any sane solution I duct-taped bottom of the cell and suddenly multimeter showed the 0V! What the hell? How is this possible? 

Yes, the Wina cells are in aluminum chassis, not the plastic one as Winston, Calb, Sinopoly and this kind of cells. But the chassis should not be connected to neither minus pole of the cell, or even plus pole! Right? And even if it would by some kind of manufacturing fault, there are several layers of plastic film sticked and heat-shrinked over the aluminum body of the cell. I checked it so much in detail and it really seems to be without damage. It would have to be microscopic! Is this some kind of electromagnetic induction or what is it?  Please help.

PS: I still can measure parasitic voltage from 0.3V to 1V at different spots around the car between the traction battery cell poles and vehicle chassis. I suppose some other cell(s) is behaving the same weird way. I want to assure that this is really a mistake before disassembling everything.


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## eldis (Sep 3, 2013)

mira9_cz said:


> Today I also experienced very weird observation. I must say I'm not sure what it is, I suspect defective cell, but how? PLEASE HELP.


Hi Mira, how are things going in CZ?
To your problem - important is to realize what you are actually measuring. You will probably find quite high voltage between two cars, just by touching chassis of each one of them with one probe. If you disconnect your house from power, you will still find quite high voltage in your 230V socket. That's why electricians don't use voltmeter with several MOhms of internal resistance - you can be perfectly measuring some charged capacity between two metal object and seeing stable voltage, while no current would actually be present. To be sure you could take a big resistor (tens of kOhms, rather few Watts rated to be safe), put it between those two points you were measuring with your voltmeter and then measure voltage on this resistor. You should see that there is no voltage anymore and no current flowing through your resistor. If it is, you indeed have an isolation problem.


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## mira9_cz (Feb 27, 2013)

Hello, things are going well, thanks. Also thank you for input. I think I understand what you are describing. I will do this test with resistor at the cell which was showing the biggest parasitic voltage and we will see.


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## mira9_cz (Feb 27, 2013)

I little bit calmed down about this parasitic voltage issue. I received more explanations in my native language and I understand the issue better. Through resistor I can measure 0V, so I suppose everything is o.k. 

Anyway I managed to put rest of the traction cells to Mazda together with BMS modules and tested everything. I still must connect details like fuel gauge, but this can wait as soon as I will have Mazda home, not in workshop 80 kilometers away. Also I prepared Anderson big blue connector to the trunk of the car for charger test. 

It all resulted is first test drive. Well if I can call it a test drive - it was about 30 meters out from workshop, around a yard and back. Everything worked perfect, what a feeling! I don't want to drive her much before I will finish everything and will apply anti-rust protection to save poor Japanese bodywork from more rust. 

Here she is. I think the car is sitting little bit lower then before. I will weight it to see how bad it is.


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## steelneck (Apr 19, 2013)

A beautiful car, it looks to do 100 standing still..  Hope you will will match performance with the look.

About the isolation problem. Did you get the Rebbl EMC-modified Soliton? I did, and have had some quite severe (in my opinion) isolation fault within the modified controller. If you go to the back of your car, disconnect between those two cells furthest away from the controller and measure midpack from either of the two cells to chassis (half your pack between measure point and controller), how much voltage do you get? Now put a 1K resistor across you probes, how much voltage?


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## mira9_cz (Feb 27, 2013)

steelneck said:


> A beautiful car, it looks to do 100 standing still..  Hope you will will match performance with the look.


Thank you, I hope too  Let me say that I like your Granada project a lot. My father had 37 Mk1 and Mk2 Granadas through his life, so you can imagine I'm very excited how it will drive when finished!



steelneck said:


> About the isolation problem. Did you get the Rebbl EMC-modified Soliton? I did, and have had some quite severe (in my opinion) isolation fault within the modified controller. If you go to the back of your car, disconnect between those two cells furthest away from the controller and measure midpack from either of the two cells to chassis (half your pack between measure point and controller), how much voltage do you get? Now put a 1K resistor across you probes, how much voltage?


No, I purchased my Soliton inside unfinished EV and as far as I know, the controller was originally purchased at ev-power.eu. Sorry but it will take some time for me to measure what you are proposing. Two cells you are mentioning are unfortunately in different battery boxes. One is in the rear, and the second in front-bottom box. Both are not easily accessible, so I will be able to measure this as soon as some modification will require disassembling something. 
Anyway I expect I will measure not the same voltage value and also that I will measure 0V at both cells through 1K resistor. I noticed that voltage of the cells which are touching the aluminum battery boxes can be measured against the ground, but those cells which are sitting at mirelon insulation foam does not seems to cause any mess.


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## mira9_cz (Feb 27, 2013)

This is today's progress:

It will not be any more orange then this, I hope that is enough.



















The biggest success is that anti-corrosion preparation is done, so I could start fitting wheel arches and other plastics to the car. 
Also Soliton controller cooling pump and radiator is in position. You can notice the small radiator at the picture below. I must buy some hoses and accessories to finish this job, hopefully next week.










And there I will fit mennekes one day


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## mira9_cz (Feb 27, 2013)

Today's progress:

Modified front torsion bar is in place. As you can see, it has been cut to three pieces. The middle one was replaced with aluminum plate and screwed to modified ends with reinforced stainless-steel screws. This plate is clutched tightly between two battery boxes. 



















You can also notice that controller cooling is finished and filled with 50/50 antifreeze. The warm water from controller is first going to radiator core inside the cabin, and from there it goes to small radiator located under front bumper. There is small expansion tank which used to be brake fluid tank of Romanian ARO 4x4. I will eventually replace it with something nicer, but it will take long long time I'm afraid, this one works very good.
As a pump I used wiper motor from Ford Granada, I hope it will hold for some time. I planned to use some Bosch pump from Webasto independent heater which my friend gave me, but it is too powerful and connection to hoses would need lot of reduction pieces, which would make installation ugly. So I call it plan B in case that Granada wiper motors will be dying quickly. 

The reason why I "gave up" on radiator core and used it just for controller cooling is that my plan is to use Webasto-type hot-air heater as a vehicle heating system. Diesel-burning one is worst case scenario, but I heard that they do something which runs on E-85. I don't want to ruin my range with electric heater, I saw what it does with Leafs, C-Zeros and Berlingos and this is something I'm not ready for yet 

I was seriously considering to use car's original air-conditioning system for heating, as discussed earlier at this thread. Eventually I spoke with air-conditioning specialist who I trust and he told me that it will be very inefficient with original Denso AC-compressor, so I gave up this idea completely. One day I will perhaps experiment with some caravan AC/heaters, but now I don't need to get warm, I need to start testing how she drives!


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## mira9_cz (Feb 27, 2013)

I had chance to continue today. Making the covers for front battery boxes took almost whole day. Again I chosen cuprextite. I like it, it is light, easy to work with and should do the same shielding job. 




























Front bumper and bottom plastics are in place as well, the car is now ready for test drive. Unfortunately it was too late and raining, so next time 










Don't you guys know if there was plastic cover under the original engine? It appears like there should be some, but I can't find it and I don't know if I should continue looking for it, or if it simply do not exist.


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## mira9_cz (Feb 27, 2013)

mira9_cz said:


> And little summary what is yet to finish.
> 
> stage 1:
> 
> ...



So first phase of my Mazda project seems to be finished. I can say that the conversion is far more difficult then I expected, if you want to have the job done nicely. I counted something about 240 hours of labor. I'm working with my dad, so 240 hours each. For money spent on components and material I did not do total yet. I'm not sure if I want to know ;-)

I hope I will be able to do some real driving with Mazda next week. Right now I can say that with Soliton limited to 250A motor current it drives nice those 10 meters to workshop and back. 

Vacuum pump switch is not yet set correctly, the pump is working more then I would want even with vacuum reservoir. I must do the test drive so I would know how much I must set the vacuum switch. 

The same goes for motor cooling and controller cooling. I must heat the sensors first to know if it will switch on and off correctly. 

What is good news that there is no EMC noise to be heard in car stereo when driving at low speeds. This is good sign that I might do the good work with shielding. On the other hand, BMS looses signal from balancing modules when driving, but works O.K. when car stands. So not so well shielding job done there. I'm still quite puzzled about this. For BMS connection I used twisted pair shielded CANBus cable, there is nothing better. I even grounded shielding at the ends of the cables. Well, I missed the shielding grounding directly behind BMS Main Controller unit, so this is probably the cause. I planned to reorganize BMS cables to look better anyway, so I will ground the cables properly this time. I hope this will solve this issue.

Next very good news is, that I tested my 8kW TC-Charger unit and it works great with BMS123! I could limit the output current as much as I wanted and it also limited itself automatically regarding pack voltage and stopped at pre-set MAX voltage per cell in BMS. When I had set BMS to start balancing at 3.5V per cell, it did! Great, I can start finally driving Mazda because I know I can charge it and drive it again!! 
As you might notice, I use 312V nominal output voltage TC-Charger. It makes 104 cells. The issue here is, that I have only 98 cells. I can not just buy more cells, because it would mess with Soliton Jr. MAX input voltage a lot. Solution there appears to be BMS123. It can control output of the charger, even if the charger is rated to little bit higher output voltage then is voltage of the battery! Yet I tested it successfully with 36V charger to 24V pack and 48V charger to 36V pack, but never with 312V charger to 294V pack! It works very good.
Well and if BMS would fail and charger would have to stop automatically without any control at it's final voltage 379.6V, the cells would be little bit overcharged to 3.8V per cell. Hey, some guys charge their LiFePo4s to 3.8V on daily basis, so I see no problem in my solution.


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## dedlast (Aug 17, 2013)

mira9_cz said:


> Don't you guys know if there was plastic cover under the original engine? It appears like there should be some, but I can't find it and I don't know if I should continue looking for it, or if it simply do not exist.


Congratulations! Those covers look really nice.

My guess is there was never a cover down there since that is most likely where the oil pan hung down. It does look like there should be something there now, though. You might want to look into a sheet of thin plastic (3 or 4 mm thick) to cover that opening and protect the motor.

Bill


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## steelneck (Apr 19, 2013)

mira9_cz said:


> stage 3:
> 
> - ZEVA fuel gauge?


You may have seen my last posts in my build thread about that.. My advice would be to look for something else to give a rough indication of SoC.


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## steelneck (Apr 19, 2013)

mira9_cz said:


> When I had set BMS to start balancing at 3.5V per cell, it did! Great, I can start finally driving Mazda because I know I can charge it and drive it again!!


 Since you seem to plan on a top balanced pack, how do you plan to stop at the other unbalanced end, to not have strong cells hurting the weak ones while acceleratiing at low SoC?


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## mira9_cz (Feb 27, 2013)

dedlast said:


> Congratulations! Those covers look really nice.
> 
> My guess is there was never a cover down there since that is most likely where the oil pan hung down. It does look like there should be something there now, though. You might want to look into a sheet of thin plastic (3 or 4 mm thick) to cover that opening and protect the motor.
> 
> Bill



Thanks, I think the covers will get darker in time as the copper will oxidate. Then I will paint them with some color, cover them with sticker or something.

Anyway the bottom cover under the motor is already done, cuprextite it is again. I also covered the holes in front wheel arches with covers cut from plate of plastic.


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## mira9_cz (Feb 27, 2013)

steelneck said:


> Since you seem to plan on a top balanced pack, how do you plan to stop at the other unbalanced end, to not have strong cells hurting the weak ones while acceleratiing at low SoC?


Yes, this is quite an issue, right?  Well what to say, I designed the project in the way that this will happen only very rarely. I bought the best LiFePo4 cells that I could, apart of A123 which is not easy to get. Winas are very hard, they don't go under 3V even at 10 seconds 5C peaks. I simply hope that for my daily 100 km highway commuting 30 kW battery will be enough to not watch myself too much about efficiency. 

Also BMS123 have internal relay, which provides switching contact in case that battery voltage gets less then predefined value. This can run MIL, or even set the "turtle" mode at Soliton. This should help me to learn about how much range I can afford to use without risking any cells to get hurt, and how much more I can use if I will be easy on throttle. Then I will set SOC gauge empty level regarding the observations, and turtle mode somewhere where the cells would already go under 2.5V.

I know that these estimations are often a dream compared to reality. So nothing is final. This is why I do what I do - to learn how to do it properly.

About that ZEVA issue, thank you for the tip. This will be really one of my last worries. I'm used to drive LPG cars, where you also have no idea how much kilometers you have left. And if you drive American V8 in Europe then you can imagine that you are VERY careful to not be forced to drive on gasoline (it is scarier then turtle mode in EV!!)


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## mira9_cz (Feb 27, 2013)

OK, so first real driving happened today. I used vacation day for it, I think this is for what vacation days are, right? 

I driven 44 kilometers over the town. This is where my Mazda starts the new electric life.










Mazda driven very smoothly. Mr. Plamen was right, the Alpha is much quieter then Kostov K9 which I can compare with. I can say that the car feels very very nice. It is not recognizable that it is not factory-built vehicle, but hand built prototype. I can compare with Golf Citystromer, RAW4 electric (old one), C-Zero, Leaf and few conversions, and I must say my Mazda seems to feel smoother, quieter, more solid. But also heavier. I'm really pleasantly surprised! Even with no power steering the drive was really very enjoyable. 

I driven only temporary unshielded cables from BMS and Soliton to interior, but the interference under the throttle were to much and readings from both Soliton logger and BMS were failing. So I gave up collecting the data and just limited battery and motor current to 350A and driven around the town. I must say I have available those special license plates, which are determined for testing of vehicles that are not approved for use on public communications, so I have done nothing illegal. 

Behind the Mazda there is the reason why!


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## mira9_cz (Feb 27, 2013)

After the driving I tested some charging as well. Everything ran very well, but I had no time to finish full charing cycle. The grid capacity in old building did not allowed me to charge more then 10A, so I charged to 3.4V (3.38 weakest, 3.4 strongest) in about an hour and left home.










Capacity gauge does not yet know what to show, current meter is showing random nonsense and temperature is not really important, so I can say I use BMS only as a voltmeter right now.










Here it is.










When I was trying to fit Czech license plates to the car, I had to remove original different sized Austrian license plates holders (those plastic things between the plate and car's body). I noticed that the car is much nicer when license plate is under the grill, then if it is in the grill. So I fitted the Czech license plate holder this way. I also remembered some RX-8 which I had seen in my friend's workshop, which had big Mazda emblem inside the grill, like those new Mazdas have. So I removed emblem from plastic cover of original ICE engine and put it into the grill. It does not look bad, although it seems to be quite small, right? I think in time I will buy emblem from 2013 Mazda 6, this one seems to be huge, and will put it to my car  










Controller cooling worked, but granada wiper motor was leaking little bit, so I changed it for wiper motor from some other old Ford. Motor cooling worked like charm, switched on and off and continued to work even if I switch off the ignition, before the temperature drops enough. 
I hope that tomorrow I will be able to drive her again. I'm going to find some shielded UTP and USB cables now, so I can bring some readouts like amount of voltage sag, current when driving flat road and other crucial data.


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## mira9_cz (Feb 27, 2013)

I also took not very interesting video of careful driving Mazda out from the workshop. This is the only road from there, it was good test of riding height. It went without a scratch.

https://www.youtube.com/watch?v=Hzm9Fwz-xUA&feature=youtu.be


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## eldis (Sep 3, 2013)

Congratulations, Mira! Keep up the good work


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## favguy (May 2, 2008)

Great work, can't beat the first drive in your own handbuilt EV


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## dladd (Jun 1, 2011)

Looks great! Congratulations on the successful first drive.


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## Archiv3r (Aug 11, 2014)

oh wow, it looks great. im totaly hooked up since i found one of these near me with a blown engine and with a good price.

congrats on your conversion, i learned a lot about it. 
however i am thinking of putting kostov 9" or kostov 10" into my ev.

i saw you said that kostov 9" is pretty noisy, is it the same with 10" ?
also, where did you order it from and how much did it end up costing? along with coupler and adaptor plate.

Cheers


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## mira9_cz (Feb 27, 2013)

Thank you guys for positive feedback.

Today I managed to drive 25 kilometers, this time with logging from soliton. What makes me puzzled is the graph below. This is simple graph of motor current, battery current and pack voltage under heavy acceleration from 0 to about 110 km/h, starting at 2nd gear and ending at 5th. 

I have the current limited to 400A now. My 100Ah battery pack voltage with no load is about 330V and the lowest value under 4C was 298V. I'm satisfied with this, this means 3.0V per cell. This makes me think 5C will be still ok for the cells and 6C peaks possible (600A - max for Soliton Jr.). 

What I find strange is that motor current and battery current is almost the same. Sometimes battery current is more then motor current. Motor voltage is 250V and the pack voltage is 330V. What happens with those watts "in between" ? (330V - 250V = 80V; 80V x any current = lot of watts which seemingly goes nowhere). In soliton setup menu I limited motor current to 400A and battery current to 350A, but both currents still keeps the same more or less all the time.


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## mira9_cz (Feb 27, 2013)

Archiv3r said:


> oh wow, it looks great. im totaly hooked up since i found one of these near me with a blown engine and with a good price.
> 
> congrats on your conversion, i learned a lot about it.
> however i am thinking of putting kostov 9" or kostov 10" into my ev.
> ...


I never said 9' is very noisy, I just said Alpha is very quiet. I would not like you to understand from my words that K9 is noisy motor. It is not noisier then Warp 9 or any other 9' motor. 

Well I bought adaptor plate from Canev.com and the motor I bought directly from Kostov motors. It costed the same as they mention at their web site, 825 USD for adaptor and 2700 USD the motor. I don't remember the shipping costs to Czech Republic. If you want to know, send me a PM, I will look into old papers for you, but keep in mind I bought it almost a year ago, so checking the up-to-date price with manufacturer is worth it if you mean it seriously.


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## mira9_cz (Feb 27, 2013)

Here is graph of 7 kilometers driving 80 - 90 km/h with other traffic. Road was not flat, there were some small hills. As you can see, the battery current and motor current curves are identical.


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## mira9_cz (Feb 27, 2013)

And here is the same graph, with added RPM curve, if somebody would want to see it. For now I limited RPM to 5400, for sure and better motor running-in.


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## dladd (Jun 1, 2011)

mira9_cz said:


> Thank you guys for positive feedback.
> 
> Today I managed to drive 25 kilometers, this time with logging from soliton. What makes me puzzled is the graph below. This is simple graph of motor current, battery current and pack voltage under heavy acceleration from 0 to about 110 km/h, starting at 2nd gear and ending at 5th.
> 
> ...


Since no one else more knowledgeable has said anything, I guess I will... This cannot be correct. Motor current is not equal to battery current, something is wrong in your logging or graphing here.


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## skooler (Mar 26, 2011)

dladd said:


> Since no one else more knowledgeable has said anything, I guess I will... This cannot be correct. Motor current is not equal to battery current, something is wrong in your logging or graphing here.


Just seen this.

Agreed.

Have you go the soliton logfile output (notepad doc)?


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## mira9_cz (Feb 27, 2013)

Thank you guys for reply, I appreciate it. I guess Tessaract is enjoying vacation, he is usually first one to reply Soliton issues 

Everybody who I discussed this issue with told me the same - mistake in logging. The graphs are correct, there is not much to mess up with Excel. Of course I double checked in log TXT, and yes, the motor current is little bit lower, but only insignificantly. Please download attachment of this post, I packed the TXT log from Soliton logger into ZIP file.

It was recommended to me to verify the soliton readings manually, but I wold need some device capable of measuring current and also having PC connection/logger, so I could reach the spot of measuring and drive the car simultaneously. And I need two of these, because I think it is impossible to repeat the same current driving twice, one drive for battery current and second for motor current. Two high voltage modified Cycle Analysts would do the job, but there must be some better solution, preferably without any measuring if there is not something wrong with soliton! There is no reason to suspect something that worked well for quite some time (even it was at 144V both pack and motor voltage).

There is "Maximum motor power" to set in kW in soliton. I have this set to "safely too much" 150kW. This is the only setting which I think might have some influence, but I doubt this a lot.


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## Tesseract (Sep 27, 2008)

mira9_cz said:


> Thank you guys for reply, I appreciate it. I guess Tessaract is enjoying vacation, he is usually first one to reply Soliton issues


I haven't had a vacation since 2004 and sending me PMs asking for tech support is one of the reasons why... ahem.



mira9_cz said:


> Everybody who I discussed this issue with told me the same - mistake in logging. The graphs are correct, there is not much to mess up with Excel. Of course I double checked in log TXT, and yes, the motor current is little bit lower, but only insignificantly. Please download attachment of this post, I packed the TXT log from Soliton logger into ZIP file.


Battery current is not reported by the Soliton - you have to calculate it from duty cycle and motor current. What you are calling battery current on your graph is actually the current that throttle is requesting (ie - Thrtl).

See, for example, this line pulled at random from your log file:



> Time CPU Thrtl MotorC PWM PackV Temp RPM In1 In2 In3 12V Mode
> 1011200 50.55 400 399 71.10 298 57.20 4736 0.02 0.00 0.00 13.46 5 Running


Motor Current (MotorC) is 399A and duty cycle (PWM) is 71.1 so battery current if 284A.


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## mira9_cz (Feb 27, 2013)

Tesseract said:


> I haven't had a vacation since 2004 and sending me PMs asking for tech support is one of the reasons why... ahem.
> 
> Battery current is not reported by the Soliton - you have to calculate it from duty cycle and motor current. What you are calling battery current on your graph is actually the current that throttle is requesting (ie - Thrtl).
> 
> ...


Hello and thank you very much for explanation. Now it makes sense. Sorry for noticing you about my request here through PM, I understand how busy you are, I will never do it again.


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## mira9_cz (Feb 27, 2013)

So here is the graph corrected.


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## Tesseract (Sep 27, 2008)

mira9_cz said:


> Hello and thank you very much for explanation. Now it makes sense. Sorry for noticing you about my request here through PM, I understand how busy you are, I will never do it again.


No, no... it's okay to ask me via PM to look at a thread, just don't ask for tech support, specifically, via PM; send an email to our support address instead. The reasons are both so that we will have a record of your incident and because several people are copied on the support address which relieves me of some of the work involved..


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## mira9_cz (Feb 27, 2013)

I spent last three weeks testing the Mazda how it performs. I driven little bit over 2000 km.










- Range is o.k. The longest route I managed to drive per one charge is 170 km. The cells were not very charged and balanced. MAX cell was 3.45 and MIN cell 3.32V. So I think it can be better. I did not planned to test the range, so first 100 km were like if I drive ICE car. My guess is that 200 km is possible. I just remind I have 98 of 100Ah LiFePo4 cells. And I do not have capacity meter yet.

- I can safely keep 130 km/h at the highway for those 100 km I need to drive almost daily with motor current 165 Amps at flat road. When I arrive, 3.26V lowest cell, 3.31 highest cell. Feels like there would be few more miles left there, good.

- The car is very fast. What is more surprising for me is that highway regime is about the same current requiring as driving slow at smaller roads. I'm still monitoring this carefully, but as far now as I can say highway at 110 to 120 km/h is the best for car to go efficiently. On the other hand keeping 80 km/h at flat road "costs" the same 160 Amps of motor current.

- After my 100 km of highway commuting I charge now only from 16A socket. I charge the pack from "empty" 321V to "full" 330V by 9.4 to 9.8 Amps for 6 to 6.5 hours including balancing. Roughly calculating that would be something under 20 kWh/100 km. I think it is not bad and sure will be better as far as I will measure it for real.

- I still have motor current limited to 400A. I feel better to not load the motor with full current capacity of the controller for first few thousand miles. I also found out that I really do not need more to keep up with most of the cars at the highway or out of it. 

- 1st gear I use very rarely, only in rush-hour.
- 2nd gear I use for drive-offs, then I usually skip to 4th and use it up to 100 km/h. 
- 3rd gear is very good for speeds from 50 to 60 km/h, so perfect for city driving
- 4th gear feels very short. It is too heavy for city driving and too noisy for stable keeping of 90 km/h. Mazda gearbox is noisy. It is interesting how much noises car does when you do not hear ICE noise. 
- 5th gear - noise stops there, this is 1:1 gear. I use it at highway, 130 km/h is very suitable speed - motor goes about 4500 RPM
- 6th gear - good for speeds over 140 km/h
- I must say that gears could be placed little bit better, but I have motor limited to 5400 RPM. I think manufacturers limit is 5800 RPM, but again, for first few thousand miles I do not want to push it. Anyway I expect improvement when I will rise RPM limit, I think with more RPM I will be able to reach even higher speeds at all gears, which will make them all normally usable without any accidental hitting of RPM limiter. I must not forget that Mazda might driven by some other people from time to time, so I must be sure to make car user friendly (user indestructible).

- RPM signal is interfered and skips plus minus 200RPM, which makes controller to limit my RPM sometimes at 5000RPM, sometimes at 5200RPM. I must do something with this as a first thing! I totally forgot about this advice of Tesseract some time ago with those condensers at motor poles or what it was (not sure, must find it and study), so I think there is space for improvement as well. 

- BMS current sensor is interfered too, making capacity meter unusable. It proved to be difficult to find 4-wire shielded twisted pair cable without necessity to buy 100 meters of it. Do you think shielded UTP networking cable might be all-right? 

- With controller input voltage limit 340V and with 98 cells I can not afford to charge over 3.47V per cell. Well I can, but then I must wait until the voltage of LiFePo4 drops automatically near 3.3V nominal voltage. Some cells will drop more, some less, you know the drill. This is nothing I would like to live with. Truth is that such a low charging final voltage is prolonging my LiFePO4s lifetime, but on the other hand it feels like I would be loosing considerable amount of range. I live with feeling that LiFePo4 cell can be considered as charged from 3.5V above, 3.6V optimal. Below 3.5V the charge curve is very flat so I think it is definitely less safe to say that all cells are at the same SOC at 3.45V then if they would be at 3.5V. What you guys think? Is 3.45V problem?

- Honestly I never expected I will be able to top-balance all 98 cells with just 1A balancing current of BMS. But I made it and all the cells reaches 3.4V per cell at same time, then I'm balancing them up to 3.45V per cell. This takes about 10 minutes maximum now for last 4 cycles!! If I remember how long takes until Leaf or C-Zero are balanced, I feel good about Mazda. But again I'm afraid this is just matter of shape of LiFePo4 charge curve and in reality I balanced nothing. But I must say this is not improving any more and strongest and weakest cells seems to be still the same ones. I will watch it further.

- Using 200Ah board 12V battery and no DC-DC converter works good. It is o.k. to charge such a big board battery once per 500 km (now, still without power steering!). Everything went well until Chinese charger did not stopped charging and I noticed this at 16.3V  One of those not very superior GBS 200Ah cells leaked a bit and destroyed BMS balancing module below itself. So those green monsters are going out sooner or later. DC-DC will replace them together with some smaller board battery. 

- I weighted the car and it is 1640 kg including charger and accessory cables. I made some 56/2001 calculations and I would loose one and half seat now with car's 1815 kg max permissible weight. I must loose 100 kg somewhere to keep 4 seats. Loosing charger and 200Ah board battery will do something, but I'm afraid I will still have to put some cells out, if I will want to keep Mazda four-seater. I made everything aluminum, there is not many options left. 


I decided to postpone the homologation stuff to next year. I did not purchased Webasto heater yet, so I do not have much time for more necessary driving, testing and acquiring data for improvements. As soon as it will be too cold weather for driving without heating, I will disassemble Mazda again for necessary improvements and adjustments.


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## dougingraham (Jul 26, 2011)

mira9_cz said:


> - The car is very fast. What is more surprising for me is that highway regime is about the same current requiring as driving slow at smaller roads. I'm still monitoring this carefully, but as far now as I can say highway at 110 to 120 km/h is the best for car to go efficiently. On the other hand keeping 80 km/h at flat road "costs" the same 160 Amps of motor current.


Motor amps doesn't mean anything unless you multiply it by the instantaneous voltage. Motor amps alone is representative of torque. Motor amps times motor volts will give you a number that does not include the controller losses. So if you want to know how much power is needed to hold a given speed on a straight and level section of road use battery volts times battery amps. If you just want to look at a single number then the easiest is battery amps but battery sag does enter into it so battery amps is representative of power but only because the battery voltage is somewhat fixed.



mira9_cz said:


> - I still have motor current limited to 400A. I feel better to not load the motor with full current capacity of the controller for first few thousand miles. I also found out that I really do not need more to keep up with most of the cars at the highway or out of it.


You will be so surprised by how much quicker it will feel when you turn this up.




mira9_cz said:


> - With controller input voltage limit 340V and with 98 cells I can not afford to charge over 3.47V per cell. Well I can, but then I must wait until the voltage of LiFePo4 drops automatically near 3.3V nominal voltage. Some cells will drop more, some less, you know the drill. This is nothing I would like to live with. Truth is that such a low charging final voltage is prolonging my LiFePO4s lifetime, but on the other hand it feels like I would be loosing considerable amount of range. I live with feeling that LiFePo4 cell can be considered as charged from 3.5V above, 3.6V optimal. Below 3.5V the charge curve is very flat so I think it is definitely less safe to say that all cells are at the same SOC at 3.45V then if they would be at 3.5V. What you guys think? Is 3.45V problem?


If a cell rests for 12 hours and the resting voltage is somewhere between 3.38 and 3.40 volts it is fully charged. Whenever the voltage of a cell during charge goes above about 3.45 volts there is a potential of overcharging the cell. The algorithm for charging goes above this level in order to speed up the last little bit of charging. Many of the vendors specify taking the charge voltage up to 3.6 volts per cell and then holding it there until the current drops to C/20. In the case of 100AH cells this is 5 amps. If you lower the constant voltage number you need to change the cutoff current. At 3.45 volts you can probably allow the current to decline to zero amps without any issues. (A123 specified 3.45 volts as the float voltage for a cell that I have a data sheet for.) At a CV of 3.5 volts it has to be allowed go to a lower current in order to fully charge the cells. But you are talking about only one to two percent away from full if you just stop as soon as you see the voltage start to rise quickly. The higher the charge current the less full the cell will be. If you were charging at 3C with a level 3 charger (300 amps in your case) you might be only 90% charged when you reached 3.6 volts. If you charge to 3.47 volts and let the charger taper to (just guessing here) 1 amp you will be at the same state of charge as you would if you go to 3.6 volts and let it taper to 5 amps. 




mira9_cz said:


> - Honestly I never expected I will be able to top-balance all 98 cells with just 1A balancing current of BMS. But I made it and all the cells reaches 3.4V per cell at same time, then I'm balancing them up to 3.45V per cell. This takes about 10 minutes maximum now for last 4 cycles!! If I remember how long takes until Leaf or C-Zero are balanced, I feel good about Mazda. But again I'm afraid this is just matter of shape of LiFePo4 charge curve and in reality I balanced nothing. But I must say this is not improving any more and strongest and weakest cells seems to be still the same ones. I will watch it further.


The problem with shunt balancing when the voltage is above 3.40 volts is that it doesn't actually work. Instead of balancing the BMS is chasing the diffusion delay. Don't get me wrong, it sort of balances to a point but after that point it will never get any better. After it turns off and rests overnight (12 hours at least) check the cell voltages with a DVM that can display at least 4 digits after the decimal point. This will show you the actual cell balance. It can be compared to the values that the BMS shows you so you can find out just how accurate the BMS is. Unless they took it into account when they designed the BMS there can be several percent variation in the readings from reality. A single DVM while it might not be accurate in an absolute sense will have the ability to show you the differences between cells which is not necessarily true of the BMS. 

It sounds like you have done a really nice conversion! I would like to see some photos when you get everything the way you want it.


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## piotrsad (Apr 14, 2014)

Helloo Mira,
firstly i want to tell you GOOD JOB !

My name is Piotr im from Poland and I also start with RX8conversion.
I have BOSCH BLAC motor and i want try to use it - i looking for cheap controller.

I want start with conversion next month and try to make it during winter.

Can you support me with gearbox pflange drawing and battery box?

thanks for support 

BR
Piotr




mira9_cz said:


> There was not much time to continue at Mazda, but my last progress is quite significant step. First we have fitted Kostov motor with canev adaptor, clutch and eventually gearbox. Bolts that came with canev adaptor are too short. I guess RX-7 gearbox flange (for which the adaptor is designed) is little but thinner. Unfortunately original Mazda bolts that holds gearbox together with wankel engine are too short to be used with canev adaptor as well. It is necessary to buy new longer bolts.
> 
> 
> 
> ...


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## mira9_cz (Feb 27, 2013)

piotrsad said:


> Helloo Mira,
> firstly i want to tell you GOOD JOB !
> 
> My name is Piotr im from Poland and I also start with RX8conversion.
> ...


Hello Piotr. Good to hear that there will be electric RX-8 at Poland. This will be the closest Mazda to me  I live at Hradec Kralove, it is not far from the Poland border. Feel free to come and check my Mazda in person.

Sorry, I think I will not help you very much with the flange. I just bought it fron canev.com. To measure everything I would have to take it out which is lot of work. I plan to do this anyway within one or two months, so perhaps you can wait.

Battery boxes I done from aluminum and you can check the dimensions few pages back in the thread. I have total 5 boxes, there is simple drawing of all of them.


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## mira9_cz (Feb 27, 2013)

Hello Doug, thank you very much for your reply. I understand that motor current is not much use for statistics and comparison of driving, but Soliton does not provide information about motor voltage. I set this to 250V at the menu, but I do not know if controller decreases it sometimes. BMS now gives me battery current, so I'm working with this.


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## Tesseract (Sep 27, 2008)

mira9_cz said:


> Hello Doug, thank you very much for your reply. I understand that motor current is not much use for statistics and comparison of driving, but Soliton does not provide information about motor voltage.


Motor Voltage = Battery Voltage * Duty

The latter two parameters are reported by logger.

So, while the Soliton does not report motor voltage specifically, it can easily be calculated from the logger data. Same for battery current, which is motor current * duty.


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## mira9_cz (Feb 27, 2013)

Tesseract said:


> Motor Voltage = Battery Voltage * Duty
> 
> The latter two parameters are reported by logger.
> 
> So, while the Soliton does not report motor voltage specifically, it can easily be calculated from the logger data. Same for battery current, which is motor current * duty.


Thank you for clarification. It is quite a wonder to me that none of Soliton users wrote himself some extended logger / dashboard for your controllers and published it for other users as well. At least I'm not aware of any. My possibilities in programming are unfortunately very limited. 



Better-equipped Mazda RX-8 offers LCD screen which comes up from the dashboard. This can be replaced for 7' tablet. As far as I managed to find out from guys with ICE Mazdas, Nexus 7 or Asus HD7 fits. Now Toshiba introduced 7' Windows 8.1 tablet, it is called I think Encore Mini. This one could run normal Windows BMS software and Soliton Logger as well. If I will stick with this idea in the future, I guess I will have to pay big money to some software company to write extended and nicer "logger" for me


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## Tesseract (Sep 27, 2008)

mira9_cz said:


> Thank you for clarification. It is quite a wonder to me that none of Soliton users wrote himself some extended logger / dashboard for your controllers and published it for other users as well. At least I'm not aware of any. My possibilities in programming are unfortunately very limited.


The logger program we supply was originally intended to assist me with the development of the prototype, hence it is very basic. At some point during development we figured it might be useful/interesting to our customers, too, so we included it with the software package. We also include the source code for the logger program (in C) as well as a description of the logger UDP data format. Thus it should be trivial for a programmer of moderate skill to write a custom logger program that is much fancier/better than ours.


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## mira9_cz (Feb 27, 2013)

Lot happened with Mazda since my last update. I have over 8000 km now, 90% of this is my highway commuting to Prague. 

First major troubles occurred. Mazda is now two weeks broken, see the pics.




























Something went wrong in the motor and loosened brush holders were pushed unequally to the commuter. I was driving about 130 km/h @ motor current 160A, when clicking sound appeared. I continued slowing down freely 2 km to highway exit and stopped. The car was not able to drive anymore once stopped, and the controller showed me this very scary message, I hope it survived.










Later I will post some detailed pictures of what happened. Now the armature is already at the lathe-job for commutator repairs, and some spare parts should be on it's way from Bulgaria. I must say that Mr. Plamen from Kostov Motors provided very good support to me.

My camera broke down and I had to took the pictures with other people's cameras, so I must collect everything first. Then I will be happy to share the details with you. Even this major problem happened, I'm still very positive about the car. It drives like beauty! If only people knew that the car passing them is electric!


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## mira9_cz (Feb 27, 2013)

It is worth sharing that I installed Webasto heater. I bought used gasoline Webasto Evo 5 hot-water unit with just 33 hours of run time. The guy sold it to me with all accessories and with finished electric cables, and with assurance that it has been tested successfully running at E85. I installed it and everything seems to be working good. 

I have very bad experience with diesel hot water heater installed additionally to Citroen C-Zero. We have 3 of these cars at the company I work for, all are equipped with it and all are problematic. Webasto hot water heater needs at least 4 liters of water in the circuit, otherwise they might boil the water and it comes out. 

By this reason I decided to add 4 liter reservoir to the system just to be sure. 

I can not wait to show you the pictures as soon as it will be finished. I found great spot for the reservoir and I used very unusual material for it. As soon as it will be finished and I will have the pictures, I will share the results with you. But motor issue goes first :-(


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## mira9_cz (Feb 27, 2013)

mira9_cz said:


> By this reason I decided to add 4 liter reservoir to the system just to be sure.
> 
> I can not wait to show you the pictures as soon as it will be finished. I found great spot for the reservoir and I used very unusual material for it.



The reservoir is finished. Unfortunately the guy who welded it to me did not understood me correctly and instead of one reservoir and one smaller tanks to be used as fuel tank I have two reservoirs. 

So I wondered who will recognize from what these tanks are made of? ;-)


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## mira9_cz (Feb 27, 2013)

The Motor is back in Mazda and everything is working again. Big thanks belongs to Mr. Plamen Nakev from Kostov Motors, who was very helpful during the process. I can not say 100% sure what happened because I refused to send motor to Bulgaria for expertise. My warranty expired before I managed to install motor to Mazda and since the damage was not looking so bad and DC motors are no rocket science, I decided to repair motor myself with minimum expenses. 

What happened is that by some reason the brush holders bent from their position and caused brushes to touch commutator unevenly. There was obviously great heat, the heads of rivets holding brushes fell off. The rivets still holding seems to be stretched and melted.










Brush wires loosened from brushes probably by the heat and caused some sparking too. 











Sparking damaged brush holders springs and pretty much everything around so spare parts were needed. Below see the new brush holder assembly installed:



















The commutator itself took the damage too. Two bars appeared to be lifted, but after repairs commutator looks all right.











After installation the motor runs 1000% quieter then before. No vibrations, no ringing noise of metal covers of the motor at high RPM. By this reason I think the motor was not all right from the beginning. You might remember me being suspicious first time I ran it:



mira9_cz said:


> I must say that I think my K11 Alpha is not very well balanced. Flywheel is machined and balanced precisely, so the motor is the only one the suspect with no gear shifted at the gearbox. My only other experience with similar DC motor is with Kostov K9 and I must say K11 I find noisier. You can hear that the sound of motor changes a little bit at the same time of each rotation. Also if you touch the car practically anywhere, you can feel vibrations in the same frequency as the motor sound. I remind that I kept original silent-blocs for Kostov motor holders.
> I will continue with motor run-in at 12V, we will see how much it will improve. I think both noise and vibrations will disappear at higher RPMs, but still.. I tried to film the video, but I did not managed to capture the noise. I will try again later as soon as I will get the chance.



Machinist who repaired the motor at the lathe gave me extensive explanation of what was wrong with the motor, but at this time I do not consider it important. On the other hand obvious thought now is if my cooling is sufficient or not.

I use this board which checks resistance from motor thermistor and actuates the relay switching the cooling fan on at 60C degrees. Plus this board can switch red MIL on at 120 C degrees. The red MIL never came on, and the fans were always switching on and off absolutely reliably! Power for motor fan is connected to permanent plus, so the fans stays on for as long as needed even when I leave the car. On the other hand I hear it rarely when the car is driving, but this I think is because of enough air flow coming through front bumper. 
From time to time (when I think I drove harder then usually) I lie under the car with red-dot thermometer immediately after driving and I never saw more then 88 C degrees measured at the motor stator.

Question what is puzzling me is how it is possible that 120 C degrees MIL never came on, but the brush holder rivets are melted and brush wires came out of brushes!? I tried to connect the same KTY thermistor instead of motor sensor and heat it with hot-air pistol. The MIL was working correctly. It makes me think the temperature is not collected correctly.


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## mira9_cz (Feb 27, 2013)

Ok, time for winter update. Since I had repaired the motor I did not drive the car. Not only because I want to protect it from salty roads, at least this winter, but especially because I planned to do some more work. Well I expected more but at least something.

- Webasto heater water reservoir installed, heater system filled with pink antifreeze and tested with plastic bottle instead of fuel tank. Still searching for some suitable tank. I'm afraid this winter I will not use the heater at all 

- EMC noise reducing capacitors installed across motor terminals as advised by many. Did not drove the car properly yet, so I really do not if it made some difference.

- My car is low-rider. The front is all right, it looks quite good and wheel alignment is correct. But the rear wheels camber is not right. So in short: 
_New rear springs made of thicker wire - expensive and might get more expensive if it will not fit correctly. 
_Air suspension: difficult to find some which does not lower the ride but does the opposite, expensive plus very stiff at max and min positions. 
_Air shocks, those you fill with tire compressor - I can not find suitable for Mazda RX8, this would be my preferred way.
So the only option left is to add spacer under the stock shocks. With help of temporary spacers I found out 33 mm added will make my car look all right again. I will send some picture as soon as the spacers will be finished.

- I'm installing my 8 kW TC-Charger under the car, instead of fuel tank. I had split it in half. It was not difficult since it is actually made of four 2kW units. I think I might violate the charger warranty rules  Now the machinist is making me some aluminum back-plates so I could finish the chargers waterproof again. 

- The Meanwell 1500W DC-DC unit fits nicely right above the driveshaft. Great location, minimum of dirt and water gets there somehow, the spot is very clean unlike the rest of the car's bottom.

- I want to add switching DC contactor to switch traction plus pole between charger (if ign off) and DC-DC (if ign-on). It seems to be elegant solution of many issues with connection of both DC-DC and Charger, but I'm in troubles finding right contactor. The smallest Albright reversing model is still too big, plus quite hard to get in Czech Republic. And ebay is full of those "Albright equivalent dc contactors" which I do not know if I can trust. I tried some ATV-winch reversing piece of crap from ebay, which had broken fist time I had tested it. So I keep searching. Any tips?


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## mira9_cz (Feb 27, 2013)

Here is the car with 30 mm temporary spacers above rear shocks. I think it is looking good.


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## tylerwatts (Feb 9, 2012)

Looks very good!


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## skooler (Mar 26, 2011)

Does look good. How does it drive with them?


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## mira9_cz (Feb 27, 2013)

skooler said:


> Does look good. How does it drive with them?


I do not know yet. Temporary spacers are two 1.5 cm tall nuts put between the shock damper and the body where rear damper is mounted. 6 nuts at each damper. Driving with this is not possible, only slowly to workshop and out. Below check how the spacer will look like. Instead of single 33 mm spacer at each side I had eventually ordered eight of 10 mm spacers, so I could add or remove them in case the car would sit even lower over the time. If somebody of you guys would use such a spacers as well, I can ask my machinist to do more of it from the nylon and send it to you.











NOTE: "pr." = diameter


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## Tesseract (Sep 27, 2008)

mira9_cz said:


> - EMC noise reducing capacitors installed across motor terminals as advised by many. Did not drove the car properly yet, so I really do not if it made some difference.


I sure hope those capacitors are only wired across the armature (ie - not across the motor controller output terminals) and that they have a ripple current rating of at least 10% of the motor current setting.

I certainly wouldn't recommend wiring capacitors across the motor armature in an attempt to solve an EMC problem; that's something that's usually only done with fractional kW power motors, as the aforementioned ripple current requirement results in very costly capacitors.


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## mira9_cz (Feb 27, 2013)

Tesseract said:


> I sure hope those capacitors are only wired across the armature (ie - not across the motor controller output terminals) and that they have a ripple current rating of at least 10% of the motor current setting.
> 
> I certainly wouldn't recommend wiring capacitors across the motor armature in an attempt to solve an EMC problem; that's something that's usually only done with fractional kW power motors, as the aforementioned ripple current requirement results in very costly capacitors.



Hello, thank you for noticing. I'm afraid I had installed capacitors across armature and also motor terminals regarding drawing below:












Tesseract said:


> Broadband RF noise is also produced by the brushes sparking. This can be reduced/eliminated by placing a small value film capacitor across the *armature* terminals of the motor (NOT across the motor as a whole!). For RFI suppression 0.1uF (100nF) is generally most effective, but anything from 47nF to 1uF will work. Note that a 100nF capacitor might have to carry 1A or more of current at 8kHz depending on the battery pack voltage, so use a physically large capacitor with wide/flat terminals. IGBT "snubber" capacitors are a good choice for this application.


I had installed 3 pc of 1uF and 3 pieces of 100 nF of those big Vishay snubber capacitors. The Wima pink capacitor laying at the paper with drawing was recommended to me, but Vishay capacitors were looking much more tough, so I used them. Datasheet of Vishay capacitors.


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## Tesseract (Sep 27, 2008)

mira9_cz said:


> Hello, thank you for noticing. I'm afraid I had installed capacitors across armature and also motor terminals regarding drawing below:
> ...
> I had installed 3 pc of 1uF and 3 pieces of 100 nF of those big Vishay snubber capacitors. The Wima pink capacitor laying at the paper with drawing was recommended to me, but Vishay capacitors were looking much more tough, so I used them.


So you totally ignored the advice I gave you earlier in the thread:



Tesseract said:


> ...Broadband RF noise is also produced by the brushes sparking. This can be reduced/eliminated by placing a small value film capacitor across the *armature* terminals of the motor (NOT across the motor as a whole!). For RFI suppression 0.1uF (100nF) is generally most effective, but anything from 47nF to 1uF will work. Note that a 100nF capacitor might have to carry 1A or more of current at 8kHz depending on the battery pack voltage, so use a physically large capacitor with wide/flat terminals. IGBT "snubber" capacitors are a good choice for this application.


Either remove those capacitors or move them so that the field is in series with them (ie - across the armature).


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## mira9_cz (Feb 27, 2013)

Tesseract said:


> So you totally ignored the advice I gave you earlier in the thread.
> 
> Either remove those capacitors or move them so that the field is in series with them (ie - across the armature).


Sorry, I'm not very sure with this issue and honestly I'm not sure if I translate/understand "across" correctly. Is this what you mean?


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## Tesseract (Sep 27, 2008)

mira9_cz said:


> Sorry, I'm not very sure with this issue and honestly I'm not sure if I translate/understand "across" correctly. Is this what you mean?


No. All series DC motors used in EVs have 4 terminals on them: S1 & S2 are the field while A1 & A2 are the armature, while a jumper connects one of the S terminals to one of the A terminals. If you insist on using the capacitors then you must wire them across A1 & A2. Otherwise, remove all of the capacitors.


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## mira9_cz (Feb 27, 2013)

Tesseract said:


> No. All series DC motors used in EVs have 4 terminals on them: S1 & S2 are the field while A1 & A2 are the armature, while a jumper connects one of the S terminals to one of the A terminals. If you insist on using the capacitors then you must wire them across A1 & A2. Otherwise, remove all of the capacitors.


I'm doing my best to understand and I took the kostov pdf to see the armature and field connection. They use different letters but I hope I understand it right. Is this now correct?


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## skooler (Mar 26, 2011)

Not sure I understand the reasoning behind using the caps? Is it to reduce emi / noise? If so why? I have exactly the same setup as you and dont have the issue.


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## Tesseract (Sep 27, 2008)

mira9_cz said:


> I'm doing my best to understand and I took the kostov pdf to see the armature and field connection. They use different letters but I hope I understand it right. Is this now correct?


Yes, but in any event do not install the series connected capacitors with the center-tap grounded to vehicle chassis.


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## mira9_cz (Feb 27, 2013)

skooler said:


> Not sure I understand the reasoning behind using the caps? Is it to reduce emi / noise? If so why? I have exactly the same setup as you and dont have the issue.


I'm still in troubles with em noise. Rebbl RPM board gives me messy signal which does not allow me to run motor any close to max RPM. Also BMS communication shuts down once I step on throttle pedal. I still have EHK10 electromagnetic compatibility tests to pass and I'm not sure if it is even worth trying with symptoms like this.
Those who watch my thread know that I'm concerned about this stuff from beginning, so I use shielding everywhere I can, with proper grounding. This capacitors remained last thing to try.

You really do not experience any noise in radio? Also where is your rebbl board located?


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## mira9_cz (Feb 27, 2013)

Tesseract said:


> Yes, but in any event do not install the series connected capacitors with the center-tap grounded to vehicle chassis.


Thank you very much for advice. The guys who recommended me the previous connection advised me that I will get better results having 1uF capacitor and 100 nF cap in parallel. Is it really advantageous against wider range of interferences, or using single 100 nF capacitor is the right way to go?


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## Tesseract (Sep 27, 2008)

mira9_cz said:


> Thank you very much for advice. The guys who recommended me the previous connection advised me that I will get better results having 1uF capacitor and 100 nF cap in parallel. Is it really advantageous against wider range of interferences, or using single 100 nF capacitor is the right way to go?


There is not a simple answer to this question. The 100nF capacitor will likely have a higher "self-resonant frequency" and so will act as a capacitor to a higher frequency, but this kind of advice really only applies to capacitors on PC boards, not ones that are wired across motor terminals several cm apart.

Furthermore, EMC problems can be exceptionally difficult to solve and often require hiring a specialist engineering firm, especially if regulatory compliance is required (in which case they are almost always hired to at least do pre-compliance testing). If switchmode power conversion (what I specialize in) is black magic then EMC is the blackest of black magic.


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## skooler (Mar 26, 2011)

mira9_cz said:


> I'm still in troubles with em noise. Rebbl RPM board gives me messy signal which does not allow me to run motor any close to max RPM. Also BMS communication shuts down once I step on throttle pedal. I still have EHK10 electromagnetic compatibility tests to pass and I'm not sure if it is even worth trying with symptoms like this.
> Those who watch my thread know that I'm concerned about this stuff from beginning, so I use shielding everywhere I can, with proper grounding. This capacitors remained last thing to try.
> 
> You really do not experience any noise in radio? Also where is your rebbl board located?



Interesting.

I have no noise whatsoever in the radio.

All I have is the high pitch soliton whine - need to set it to quiet mode. Most people cant hear it but I guess my ears are more sensitive.

Rebble board is wired as per instructions and simply heatshrinked up and free floating next to the controller. Shame it doesnt come in a proper box or the kostov put out a simple pulse.

I do have an occasional issue with my power steering not firing up which could be noise related.

No emc test to pass in the uk, would be interesting to do one though!


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## mira9_cz (Feb 27, 2013)

I had lost my notes from my progress with CAN Bus, so I had to start with the job again. This time I knew little bit more what I want to do and how I should do it in the software I have. It showed our that my spare instrument panel I have for experiments has complete MIL section damaged, so four instrument panel functions only is everything I can control now.

Can speed is 500k, I'm sending messages periodically at 100 ms.


RPM Meter: CAN message ID 513 (hex 0x201), length 8 bit. Controlled by B0 and B1.

0%: B0 = 0; B1 = 0
first pointer movement: B0 = 2; B1 = 200
3000 RPM: B0 = 45; B1 = 120
6000 RPM: B0 = 89; B1 = 0

The two bits resolution is unnecessarily big I think, because the analog gauge can not show so detailed values. I think controlling RPM gauge for Kostov K11 Alpha is very much possible only by linear signal where B0 = <0 - 89>, but Power Steering Controller will definitely need the full range for correct and error free operation. 
If I will translate high resolution pulse output of Kostov K11 Alpha sensor into CAN messages for Instrument cluster AND PSC, I think it should be relatively easy and very elegant to integrate signal divider and make my own Rebbl signal converter board. 


Speed: CAN message ID513 (hex 0x201), length 8 bit, Controlled by B4 and B5

0 km/h: B4 = 39; B5 = 16
1 km/h: B4 = 39; B5 = 61
2 km/h: B4 = 39; B5 = 157
3 km/h: B4 = 39; B5 = 255
4 km/h: B4 = 40; B5 = 100
298 km/h: B4 = 154; B5 = 200
299 km/h: B4 = 155+ B5 = 0

Again the resolution is very big, but digital gauge can use more of it. I think speed CAN messages are sent by ABS computer, because there is no connection for ABS wires in Power Steering Controller. Since power steering assist amount is speed dependent, it means that PSC will probably need to be fed by speed signal in full resolution of two bits to prevent errors. At least it seems to be linear. So I will have to catch the signal from vehicle CAN line and send it into PSC over separated CAN line to protect PSC from nonsenses sent by ECU.


Oil Pressure: CAN message ID 1056 (hex 0x420), length 7 bits, controlled by B4

0% oil pressure: B4 = 0
75% oil pressure: B4 = 1

This is all, the gauge is kind of fake, it might be simple MIL and the user would still be same informed. You can not make it show for example 25%. 
I think this might be suitable for DC/DC active / inactive status. 
The oil pressure signal (both B4 = 0 and 1) shuts off the red MIL which looks like merry-go-around, I suppose it is equivalent of "Check engine soon" MIL.


Engine temperature: CAN message ID 1056 (hex 0x420), length 7 bits, controlled by B0

no temp shown: B0 % 69
Beginning of white field (0% temp): B0 = 90
45% temp: B0 = 110
50% temp: B0 = 151
60% temp: B0 = 155
end of white field (100% temp): B0 = 165
redline (overheating): B0 = 170

Temp. readings does not appear to be linear. The pointer is significantly "slower" between B0 = 110 and B0 = 150. I would like to use temp. meter to show me temperature of the kostov motor. For this I will need my hardware to translate resistance values from Kostov motor thermistor from let's say 20 C degrees to 120 C degrees into can message 0x420 where B0 = from 90 to 170 with respect to non-linearity of the CAN message.


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## mira9_cz (Feb 27, 2013)

The problem of Power Steering not working at Mazdas with ICE removed is one of the most difficult problems to solve for successful conversion. With all necessary components comes some manual or connection scheme, but there is no manual for hacking Mazda CAN-Bus protocol. Truth is that it actually exists finished product which you can buy, Skooler uses it: http://canbusauto.co.uk/ For me this is not the right way because of two reasons. 1) I want speed adaptive PS working, this one is not (yet I guess) 2) I would be willing to pay something like 100 to 150 EUR for the product at most. This is not the case unfortunately. I was always interested in CAN-Bus, but was too lazy to self-study anything about it. I guess now there is my chance.

Problem with Mazda electric power steering rack is that PCM (Main Computer) is confused of loosing lot of data from ICE sensors, which are no longer present at converted E.V. . By this reason PCM refuses allowing PSC (Power Steering Controller) to operate and power steering simply does not work.
PSC is connected to PCM through CANBus. CANBus line is shared with other CAN devices at the line, in our case it is instrument panel, ABS/DTC, Keyless entry, PCM and PSC. All devices listen to all signals for various reasons and the message flow looks like big mess. The problem is to find out the right signal(s) that PSC needs to listen in order to operate. The signal in this case is CAN Message. CAN Message has it's address, bit length and carries an information. If the signal is wrong, there still is the CAN Message with it's address and length, but it contains information wrong for us. Therefore _special hardware_ must be developed and installed into CAN network to emulate right CAN message(s) for PSC to work. Interfering with PCM is the big issue here! I think the only way how to prevent PCM interfering with our own CAN signal is to cut the PSC off the vehicle CAN-Bus network and establish separated CAN network.
At the beginning I have hoped it might be possible to simply to send some static values like 2000 RPM and 0 km/h speed signal, but apparently it is not that simple. The _hardware_ will have to dispose of certain signals Inputs to work properly.


Below is the PID/Data monitor and record table from page 35 of RX-8 Power Steering Manual:












> PID/Data monitor and record
> • This function allows access of certain data values, input signals, calculated values, and system status
> information.


So I think Power Steering Controller need following information to operate properly:

_12V battery power: _o.k.
_CCNT - DTC (Detected Trouble Codes?)_ in memory: will get to that later
_EPS Motor Drive Signal:_ PSC would have to be working first to have troubles with this
_EPS lamp:_ Whether EPS MIL at dash is on or off. This is connected with Trouble codes, so later
_RPM speed:_ FIRST important CAN-Bus information to concern with!
_Steering Neutral Position Setting:_ If I would have troubles with this, I would know because power steering would put different effort steering left and right. My PS is not working yet, so move next.
_Torque sensor:_ This is component of PS rack, providing analog signal to PSC. No reason to distrust at this point
_Vehicle speed. _SECOND important CAN-Bus information to concern with!


OK, so at this point I can be sure of RPM and Vehicle speed CAN-Message necessity. Both information are carried by message DEC ID513 (HEX 0x201). 
We must not forget about the stuff with DTC's stored plus EPS Lamp being ON at Instrument panel by that reason:

This is DTC Table from RX-8 power steering manual, page 34:










Except some DTC's related to analog problems which does not concern us right now there are CAN-BUS errors_ U0073, U1900 and U2023_. This might help us to find out what other messages PSC requires to operate I suppose, otherwise there would not be trouble code for it!

This MULTIPLEX COMMUNICATION SYSTEM table is not easy to find, eventually I had located it somewhere in the middle of Mazda RX-8 Body manual. You can see it displays more then_ U0073, U1900 and U2023_ trouble codes. Since they are not referred in RX-8 steering manual, I think I should not concern about them. I presume that they are here for other CAN nodes communication with PCM, probably ABS/DSC module.










This is EPS steering diagram from RX-8 Steering manual, somewhere about page 30: 










From Multiplex table I can see:

_U0073_: This fault could indicate something of following is not sending / responding to PSC CAN message: PCM, TCM, and Keyless entry. I can suppose there is nothing wrong with Traction Control Module or Keyless Entry, but PCM logically sends wrong data. So I suppose nothing new to worry about came from U0073.

_U1900_:This DTC can indicate ABS, DSC, Instrument Cluster, TPMS Control module, Keyless entry module or steering angle sensor are wrong. I think I can exclude Tire Pressure Monitoring System and Keyless entry because at the EPS diagram above it is noticeable that PSC works only with CAN data from PCM, ABS/DSC and Instrument Cluster. ABS/DSC communication might be the speed CAN message, I'm not sure if PCM or ABS sends it, both would make sense. The Instrument cluster is more or less working, it keeps sending CAN message ID 1072, HEX 0x430. With Inst. panel I know where to start, but Steering angle sensor is a big wonder to me right now. I suppose this sensor provides data about if whether you turn left or right, and possibly how much. I'm quite sure there must be a CAN message for it this and I'm going over and over through logs which I had recorded at my friend's still Wankel powered RX-8 with no positive results. It could be ID 129, DB2+3, but I'm still not sure.

_U2023:_ This DTC I was unable to find in any RX-8 documentation, but apparently it is somewhere there. Google found it: U2023-FF- (EPS) - Fault Received from External Node - No Status Available for this (DTC)
Honestly I do not understand this very much, it might be anything. 


To summarize: I had found out that RPM and Vehicle Speed signals are definitely necessary. I have to consider my effort to steering angle sensor information - in which form it goes to PSC. If I will cut the CAN link between PCM and PSC, I will have to emulate this signal as well, presuming the signal is CAN-Bus message. If emulating those three signals will not be enough to make PSC running, I think I will have to do something with Instrument panel and ABS/DSC Can messages. The Istrument panel message address I already have and if I'm lucky, the ABS/DSC message MIGHT be B4 and B5 of ID513 (hex 0x201).


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## eldis (Sep 3, 2013)

mira9_cz said:


> The problem of Power Steering not working at Mazdas with ICE removed is one of the most difficult problems to solve for successful conversion.


Another thing to look for is some sort of an "engine running" packet. The power steering might not start as a precaution, if it thinks that the engine is not running, as it requires a lot of power from 12V system.

The brute-force (and effective) solution here is to get a recording of all the packets (starting from ignition switch till the pump kicks in) from ICE RX-8. Then you replay this stream to your steering unit (with everything else disconnected from the bus). Luckily, it will start working. Then the detective work comes in - you just have manually filter out IDs that do not affect your steering system.

Once you isolate several IDs that cause you steering system to work, you can go back to the ICE capture and look on variations of values inside of individual packets. Having this sequence with timestamps will help (like knowing that at time 10s the car started moving, that the speed was 50km/h at time 50s, etc.).

From the hardware point of view you only need and arduino or similar with a CAN shield. Alternatively you can use commercial CAN products - it has to be able to replay a sequence on demand.

Good luck!


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## berlinger (Oct 13, 2012)

*Well said Eldis, it is exactly what I would like to say.*
* Mira, most of CAN packs you described here is connected with DSC. This car have very good stability system. I don’t know, does it uses brakes or how it does, but I can’t fool it even on ice when I drove ICE RX8. DSC need to know speed of each wheel and angle of steering wheel to work.*
* Power steering do not need speed signal to operate. It works when car do not moves, only engine must run. **Somewhere **I see 1000rpm, it can be threshold after that EPS start to work, and 20 km/h, it can be threshold when it reduces power.*
* One note about EPS MIL lamp. If you disconnect cars 12 V battery and then put it back and start motor, EPS and DSC lamps will be ON. Then you need to turn steering wheel from one side to other and back (make check) and only after that, they goes OF. May be it is U2023 CAN message.*
*Keep my fingers crossed and wish you luck with that! May be it is time to start new thread about Mazda CAN solutions?*


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## mira9_cz (Feb 27, 2013)

eldis said:


> The brute-force (and effective) solution here is to get a recording of all the packets (starting from ignition switch till the pump kicks in) from ICE RX-8. Then you replay this stream to your steering unit (with everything else disconnected from the bus). Luckily, it will start working. Then the detective work comes in - you just have manually filter out IDs that do not affect your steering system.


Hello and thank you for posting. The method you described is pretty much what I'm doing. I had recorded few logs at ICE RX8, like 10x steering wheel left with engine OFF, 10x steering wheel left with engine ON, 50 meters slow driving with turning / without turning, etc. 

Unfortunately sending the complete log into PSC is not working. I had chosen the log "standing at spot with ICE on, turning steering wheel 10x left and 10x right". It does nothing with PCS connected with PCM, but when I cut the CAN-Bus wire going to PSC and send the signal only into PSC itself, I can hear the PS motor running! Good start I guess, but no steering assist is happening.
My current theory is that the _steering angle sensor_ CAN message is the reason for this. If there is really CAN message for steering angle, I think it it must correspond with analog value provided by steering torque sensor. My thinking is if the torque sensor is changing the resistance value when steering, the PSC might expect steering angle CAN message with change in some way. Otherwise it might "think" malfunction is happening and turn off the PS.


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## berlinger (Oct 13, 2012)

* Something looks wrong for me. How I understand mazda steering rack is built, then it is impossible for PS motor “run”. It is connected to rack true gearing and can’t move separately from it! It only assist with force that comes from amps (it is why so solid wires is used). Check what made this noise!*
* Steering angle signal PSC generates for DSC, it must be outgoing message.*


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## mira9_cz (Feb 27, 2013)

berlinger said:


> Mira, most of CAN packs you described here is connected with DSC. This car have very good stability system. I don’t know, does it uses brakes or how it does, but I can’t fool it even on ice when I drove ICE RX8. DSC need to know speed of each wheel and angle of steering wheel to work. Power steering do not need speed signal to operate. It works when car do not moves, only engine must run.


I think vehicle speed signal ID513 is composed of wheel speeds, but the question is if vehicle speed signal is being composed from wheel speeds by ABS computer, or PCM.
I know speed is probably not directly required, or sending 0 km/h might work, but I still want that power reducing option. 



> One note about EPS MIL lamp. If you disconnect cars 12 V battery and then put it back and start motor, EPS and DSC lamps will be ON. Then you need to turn steering wheel from one side to other and back (make check) and only after that, they goes OF. May be it is _U2023_ CAN message.


Wonderful tip, thank you! I will also try to reach end positions of steering, perhaps it will change something. 



> How I understand mazda steering rack is built, then it is impossible for PS motor “run”. It is connected to rack true gearing and can’t move separately from it! It only assist with force that comes from amps (it is why so solid wires is used). Check what made this noise!


Yes, I'm also puzzled about what made the sound when the steering rack was not moving. I plan to do it as soon as I will go again to work at the car.



> May be it is time to start new thread about Mazda CAN solutions?


I will do this.


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## Duncan (Dec 8, 2008)

Hi
I know this is not what you want - But how does it drive without the power steering?

It's not that long ago that a car like that would not have had any power steering
My old Lancia Spyder was a very similar size - no power steering
The steering was a bit heavier than a modern car but it drove like a dream


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## berlinger (Oct 13, 2012)

* No way for that. Car is heavy, it is more than 1500 kg curb weight and nobody produces replacement racks for it. Original steering rack is ‘short’, I do not remember exactly how many turns from end to end, but it is short and even with electric motor disassembled it is too heavy to turn. We are in EU and no way to do modifications on steering system legally.*


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## mira9_cz (Feb 27, 2013)

Duncan said:


> Hi
> I know this is not what you want - But how does it drive without the power steering?
> 
> It's not that long ago that a car like that would not have had any power steering
> ...


I have driven over 8000 km without power steering already, but 90% of that was highway driving. Parking and maneuvering in tight spaces is quite hard. As berlinger says, the ratio of the RX-8 steering is sporty and PS in necessity there.


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## mira9_cz (Feb 27, 2013)

berlinger said:


> *One note about EPS MIL lamp. If you disconnect cars 12 V battery and then put it back and start motor, EPS and DSC lamps will be ON. Then you need to turn steering wheel from one side to other and back (make check) and only after that, they goes OF. May be it is U2023 CAN message.*


: 

I found out that what you described here is actually how to perform steering angle initialization procedure: http://foxed.ca/rx7manual/2003mazdarx8/esicont/en/srvc/html/BHE041566120W03.html

I wondered if this is the same thing as EPS System Neutral position setting. I also wondered what happens if you remove the negative battery cable at ICE RX-8 - Do you must turn full left and full right, otherwise PS will not work?


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## mira9_cz (Feb 27, 2013)

I checked if I can do something about light indicators not working at my test instrument panel. I'm afraid I can do nothing with this.


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## mira9_cz (Feb 27, 2013)

Last few weeks I spent deciphering Mazda CANBus in order to prepare background material for some hardware, which would secured PS working, and solved the issue with most of the indicators and gauges not working at the Instrument panel. 

Below is some easy-to-use data for anybody who is doing the same stuff. With my previous post this is everything you need to control RX-8 instrument panel over the CAN.

PSC lamp: ID 768, length 1, bit 0 = 128 LAMP ON, bit0 = 1 LAMP OFF

DSC lamp, slide lamp: ID 530, lenght 7, bit 5:
DSC OFF, slide OFF: 64
DSC OFF, slide ON: 80
DSC ON, slide OFF: 0 / 8
DSC ON, slide ON: 16
DSC ON, slide blinking: 34 and around
DSC OFF, slide blinking: 98 and around

ABS lamp, brake pad lamp: ID530, length 7, bit4
ABS ON, brake pad OFF: 8
ABS OFF, brake pad OFF: 0
ABS OFF, brake pad ON: 64
ABS ON, brake pad on: 88


Check engine soon lamp: message 1056, lenght 7, bit 5: 
0 - OFF
64 - ON
128 - blinking

Merry go round (radiator level), charging, oil pressure: message 1056, length 7, bit 6:

radiator OFF, charging OFF, oil press OFF: 0
radiator ON, charging OFF, oil press OFF: 2
radiator OFF, charging ON, oil press OFF: 64
radiator ON, charging ON, oil press OFF: 66
radiator OFF, charging OFF, oil press ON: 128
radiator ON, charging OFF, oil press ON: 130
radiator OFF, charging ON, oil press ON: 192
radiator ON, charging ON, oil press ON: 194

Berlinger, the guy with direct-drive RX-8 from Latvia is extremely helpful with this CANbus stuff. As soon as we will manage to get everything in order, we will start Mazda RX-8 Can bus thread to not ruin our conversion threads with lot of specific data.


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## mira9_cz (Feb 27, 2013)

They had finally finished rear shocks spacers for me. Each is 1 cm tall. If anybody want some, feel free to send me PM, I can let the guys make more for me. I had used three pieces above both rear dampers.










This is the spot where they should sit: 










Here is how it looks like at the position:



















The screws had to be removed and replaced with longer ones. Also the brace holding shocks inside the trunk needed some modification. The car is still hanging at the car-lift, I will post pictures how it looks from around the car later.


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## mira9_cz (Feb 27, 2013)

I'm also splitting 8 kW TC-Charger (Elcon) to half, and installing these two pieces instead of fuel tank. There are holes under stickers at fuel tank area, where M10 nuts can be easily welded into. This makes very nice spot for charger holders. You can notice the middle hole still covered with sticker. Those holes goes to hollow space of the bodywork, welding makes no harm there.










Hopefully this weekend I can finish the job with chargers and I will be EV driver again


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## mira9_cz (Feb 27, 2013)

Charger is in place, but it will take one more day to finish the cables for it. I'm afraid that if I would count all the work and expenses together with purchasing price this 8kW Elcon unit, I might have nice Brusa charger instead


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## tylerwatts (Feb 9, 2012)

Hi Mira. Are you going to cover the charger and underside of the car to protect from dirt?


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## mira9_cz (Feb 27, 2013)

tylerwatts said:


> Hi Mira. Are you going to cover the charger and underside of the car to protect from dirt?


Hi! Well I considered it and I don't know how to do it right. Any cover I imagine would ruined charger cooling significantly, but postponed fans death not so significantly. I think I will drive it few time like this and see how much dirt and where is it getting. I made the charger splashproof, at least I hope, so "only" fans should be in potential danger. See some pictures below:


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## mira9_cz (Feb 27, 2013)

It took five days to split the charger and place it under the car, I thought it will be easier. But it is now finished and Mazda can charge again. Plus it stands right with shocks-spacers, looking great.


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## skooler (Mar 26, 2011)

I thought the tc charger cant be mounted with the fins facing down? Instructions say 'forbidden'.


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## Moltenmetal (Mar 20, 2014)

Personally I would reconsider the charger location, but of course it's your money and you can pay for the replacements when they fail...!

But the car looks amazing and I think you should be very proud of the result!


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## mira9_cz (Feb 27, 2013)

skooler said:


> I thought the tc charger cant be mounted with the fins facing down? Instructions say 'forbidden'.


Good point. I did not knew that, it makes sense that it is in the manual of "flat" elcon chargers to not place them upside down. Mine was standing 90 degrees, but now it is basically upside down. Sh*t! When I imagine all the work with rotating them, cables and everything  



Moltenmetal said:


> Personally I would reconsider the charger location, but of course it's your money and you can pay for the replacements when they fail...!
> But the car looks amazing and I think you should be very proud of the result!


Thank you, I think it is not yet time to be proud. Also thank you for concern with the chargers location. I think the spot is perfect. The charger still few centimeters above the lowest point of the bodywork. And the body itself is not even the lowest point of the car, differential bolts and are much lower. Rotating the chargers now would make lot of sense. Surprisingly there might be more then enough space above the charger fans for cooling. The holders came very nice and if they would came the same way with charger upside down, it would be even better. But would take to re-do holders, together with everything. Three more days of two persons at least, god I hate myself.

What is even worse is that today I tried to charge Mazda and it does not work! I disconnected DC-DC input cables, so there will probably be connection. Charger blinks no battery connected, but it is. But after Skoolers post I miss any motivation to do anything with this charger ever again. If I will have to remove it one more time, I'm afraid it might never return back to Mazda. How much is that Brusa NLG513 air cooled?


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## eldis (Sep 3, 2013)

mira9_cz said:


> ... But after Skoolers post I miss any motivation to do anything with this charger ever again. If I will have to remove it one more time, I'm afraid it might never return back to Mazda. How much is that Brusa NLG513 air cooled?


Depending on the power you need, you could go for one or two Chevy Volt chargers (3.3kW). They costs nothing and are watercooled, designed to be splash proof. I'm using one and can't complain.


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## brainzel (Jun 15, 2009)

Eldis, where did you get your charger and what means "nothing" to you? 
Which output voltage range could they be adjusted to?
Michael


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## eldis (Sep 3, 2013)

brainzel said:


> Eldis, where did you get your charger and what means "nothing" to you?
> Which output voltage range could they be adjusted to?
> Michael


Nothing is a relative term  Got mine for $300 from some scrapyard in the US. It goes from 200V to 430V or something like that. You could charge even a 72V battery, because you just set the final voltage and a constant current, that is then maintained. Then you of course have to tell the charger to stop when your low voltage pack is full, as the minimum end voltage is 200V (t will not stop until it reaches it).


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## mira9_cz (Feb 27, 2013)

eldis said:


> Depending on the power you need, you could go for one or two Chevy Volt chargers (3.3kW). They costs nothing and are watercooled, designed to be splash proof. I'm using one and can't complain.


Thanks for the tip. Where I can buy such a charger? Local resources will not work for me. As far as I know we have three to five pieces of Opel Amperas in Czech Republic, I don't know about any Chevy Volt imported. We do not have many salvaged E.V.s here and demand for used E.V. parts is therefore huge. 
EDIT: now there are three units at ebay.com, but must be purchased all together  At ebay.de there is nothing.

I asked to Brusa about NLG513, it is little bit under 1900 EUR today, FCA Switzerland. Is this standard price today? When I googled I noticed that back in 2013 people had bought NLG513 for 1200 to 1300 EUR pretty much normally.


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## eldis (Sep 3, 2013)

mira9_cz said:


> Thanks for the tip. Where I can buy such a charger? Local resources will not work for me. As far as I know we have three to five pieces of Opel Amperas in Czech Republic, I don't know about any Chevy Volt imported. We do not have many salvaged E.V.s here and demand for used E.V. parts is therefore huge.
> 
> I asked to Brusa about NLG513, it is little bit under 1900 EUR today, FCA Switzerland. Is this standard price today? When I googled I noticed that back in 2013 people had bought NLG513 for 1200 to 1300 EUR pretty much normally.


That's probably normal. Swiss franc skyrocketed few months ago (can't complain from where I'm standing) 

Forget about getting these parts in Czech republic, I tried as well. Order it directly from the US. No Volts here. Even in Switzerland you cannot get this stuff, and I see Teslas all the time here. People just don't like to crash..


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## berlinger (Oct 13, 2012)

* Hi Mira, I must say that charger looks very organic in place you have choose for it. Did not concern so much about mounting position, just get it to work and use it! I have one in my Berlingo and only time I have seen it warm vas in hottest summer days close to full power settings. What you can lose, couple euro fans? Who knows maybe it will take many years for them to die.*


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## Moltenmetal (Mar 20, 2014)

My concern would be water into the electronics because these are not IP 56 devices. If I am mistaken, then you might be ok. Fans can be replaced easily enough but power electronics and water don't mix.


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## mira9_cz (Feb 27, 2013)

Moltenmetal said:


> My concern would be water into the electronics because these are not IP 56 devices. If I am mistaken, then you might be ok. Fans can be replaced easily enough but power electronics and water don't mix.


Thank you for input! I tried to make the chargers as waterproof as possible. There is no IP rating for the job I have done. I must hope it will be enough.



berlinger said:


> * Hi Mira, I must say that charger looks very organic in place you have choose for it. Did not concern so much about mounting position, just get it to work and use it! I have one in my Berlingo and only time I have seen it warm vas in hottest summer days close to full power settings. What you can lose, couple euro fans? Who knows maybe it will take many years for them to die.*


Thank you Artis for positive attitude! This is what I needed!  I'm using charger to 40% max, limited by BMS in 99% of charging cycles(21A circuit breaker). Honestly I'm not worried about overcharging, even with all fans dead. The charger is really only mild warm most of the times, it can very well run passive. And splitting the charger in half provided more area to contact with cool air under the car.. More than this I'm worried what dead fan can do to charger electronics. Those fans are powerful 230VAC units! Whay if they will get blocked by dirt or something? I have four spare fans from salvaged TC-Charger by the way, but of course I prefer to keep them in the shelf possibly forever.

Also if they say in the manual that upside down position as Skooler says, is not good. Chinese might mean it not only because of overheating possibility. Some of the components at PCB of Elcon/TC-Chargers are really heavy. I can imagine vibrations and upside down position might cause troubles in future.



eldis said:


> That's probably normal. Swiss franc skyrocketed few months ago (can't complain from where I'm standing)
> 
> Forget about getting these parts in Czech republic, I tried as well. Order it directly from the US. No Volts here. Even in Switzerland you cannot get this stuff, and I see Teslas all the time here. People just don't like to crash..


Yes, the exchange rate, this makes sense. Good for you  My friend is in US now and seeking for some charger for his 2001 rav4 to replace magnecharge. I gave him the tip. I hope he will find some Volt charger for me too.


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## mira9_cz (Feb 27, 2013)

TC-Charger is suddenly working again. I'm happy but it makes inevitable choice harder. Optimistic explanation is that it was only some BMS mistake in charger control which never happened before, but it can be very well anything and it may happen again. I hope it will work at least until I will find some other charger.











Also today I managed to install contactor to disconnect DC-DC from traction votage - you can notice orange GWL HZJ20012V unit above the drive shaft at the first picture. It is only temporary solution before I will find reliable switching contactor to switch between DC-DC input and charger output regarding ignition cylinder position. 12V ATV switching winch solenoid from e-bay came defective, but it seemed very well build. I will wait for warranty replacement.

This is position for Meanwell RSP1500 unit which I'm quite proud of - above the drive shaft where nothing else could be placed


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## brainzel (Jun 15, 2009)

Even if I wouldn't hang my charger under the car (I have a TC6kW unit) it could work for you for a few years, but the MeanWell wouldn't last long, if it's mounted like on your picture before.
The electronics inside should be protected from water, moisture and mud, otherwise you will risk a short circuit at least.

I bought two meanwell which were installed in a camping caravan for some years and they where totally rusted, even though they where inside (!) the caravan.

So I would recommend you at least a cover.

Michael


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## Moltenmetal (Mar 20, 2014)

That DC/DC converter will be toast where it's located. Any water which gets onto the driveshaft will be slung in every direction, and there are open vent holes on the unit. I strongly suggest finding a place inside the car to mount it.


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## skooler (Mar 26, 2011)

Agreed - it needs to be moved but cannot be mounted inside the car. One of the European standards prohibits high voltage within the passenger cabin (and rightfully so).

I got around it by mounting mine inside the boot behind a removable panel along with the 12v battery.

Really important that these have good airflow as they get quite hot.


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## Friday_EV (Dec 9, 2014)

Apologies for breaking into the topic, but while it was mentioned, is there any website where we can see the requirements/standards for EVs that have to be met in order to register the vehicle?


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## skooler (Mar 26, 2011)

Friday_EV said:


> Apologies for breaking into the topic, but while it was mentioned, is there any website where we can see the requirements/standards for EVs that have to be met in order to register the vehicle?


From a UK perspective - Nope! Did a bit of work with the DVLA on it though so should be something soon. It is almost all the EU requirements which are widely known.


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## eldis (Sep 3, 2013)

skooler said:


> From a UK perspective - Nope! Did a bit of work with the DVLA on it though so should be something soon. It is almost all the EU requirements which are widely known.


Even inside the EU states, this can vary a lot. At the end the person doing the check will have their own idea and interpretation of rules. Find an enthusiastic guy, you're fine. Find some idiot full of himself, and you will have to bring a proof of conformity for every wire you have in there.


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## mira9_cz (Feb 27, 2013)

Thank you guys for your concerns about DC-DC. I was driving with Meanwell SP-320 under the car for over a year in different E.V. with positive results. So I decided to do it again with bigger meanwell. 
This position is really very well protected. This spot where DC-DC is now was absolutely clean even after driving two months in Autumn 2014. Including messy highway driving behind trucks during heavy raining. The car is obviously designed to be aerodynamic from the bottom as well. I'm very confident that this is really good spot. Anyway we will see. If I would notice that there are splash marks over DC-DC chassis, I already have nice cuprextite splash-shield in my mind. I still must make traction voltage cables orange and put another contactor to disconnect charger from traction voltage, so there will be many opportunities to check if something is not going wrong.


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## mira9_cz (Feb 27, 2013)

Friday_EV said:


> Apologies for breaking into the topic, but while it was mentioned, is there any website where we can see the requirements/standards for EVs that have to be met in order to register the vehicle?


This is generally quite an issue. For most people it is very discouraging to build EV, if there is not absolute certainty of road legality in advance. Which never is. 
Except partial work for GWL I do homologation of vehicles for living. The target of my Mazda project is to reach Type approval of conversion of the Mazda RX type. So anybody else who will build electric Mazda RX-7 or 8 will be able to use my EU valid papers. When bureaus see that the same stuff is legal somewhere else in EU, it goes easier at the very least. I shared my idea with people living elsewhere, including Skooler and Rebbl, and nobody seems to be very interested about the idea. But I feel I should close the project with official Ministry of Transport paper, the costs of getting it in Czech Rep. are only inconsiderably higher then getting the papers only for single car. This is why I'm so serious with EMC and insulation resistance.


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## mira9_cz (Feb 27, 2013)

Today things went very very bad with my RX-8 - the motor is dead again 
I'm very unhappy now, it survived only 350 km. First 150 km was very easy trip to verify if everything works good. It did. So today I took the car to 100 km to GWL over the highway. Everything seemed very good, Alpha was quieter and almost no vibrations at all. Significant improvement there. So on the way back home I have been confident already to drive 130 to 150 km/h with other cars. I drove like this for 30 to 40 minutes and this makes about 170A continuous motor current at flat road at 5th gear, 190A at 6th gear. Soliton is still limited to 400A, but I had reached 390A max for about two seconds during the first acceleration to reach continuous highway speed. Mazda performed superb on the way back as well, I was feeling very happy driving the car finally again! Then I left highway, I slowed down to 50 km/h, drove about two hundred meters from the exit and slowly through roundabout. When I wanted to accelerate smoothly out of the roundabout, motor started doing weird sounds. I stopped immediately and being desperate I tried to restart Soliton. This caused that I can not send you the logs.
It feels like the motor does not work for about 1/3rd of each turn. It starts rotating, but misses some part of each rotation. Plus it needs 250A at least to even start rotating with no gear shifted. So I gave up trying after second attempt. When I turn with the motor not by it's own power, everything sounds smooth. I had measured max. 67C degrees at the motor chassis immediately when I stopped the car. Cooling fan was working o.k. controlled thermostatically from 45C up as usually. Fans continued running about two minutes after I stopped. This is how it always goes after highway driving, I have no reason to suspect temperature issues. Plus it was 7C degrees outside!

So I let myself towed those last 10 km home. Tomorrow I will at least remove brush cover and hopefully see what happened. Any ideas what got wrong and how could I mess this up?


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## eldis (Sep 3, 2013)

mira9_cz said:


> Any ideas what got wrong and how could I mess this up?


Sorry to hear that! Maybe some carbon build-up or a part of the copper strip on the rotor got delaminated somehow?


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## Moltenmetal (Mar 20, 2014)

Very sorry to hear about your motor problem.

About the DC/DC location, admittedly the least of your worries now, I meant inside rather than underneath the ca, rather than in the passenger compartment, ie in the trunk or under the hood.


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## berlinger (Oct 13, 2012)

* It is sad to hear about your motor problem and I hope that it was some lost connection and nothing more serious.*
* Must say that you have fun to drive car if you can hold 130-140 km/h.*


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## RIPPERTON (Jan 26, 2010)

Time to get rid of that Forklift anchor and go AC induction mate.
You don't see us regen guys breaking down on the highway


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## skooler (Mar 26, 2011)

RIPPERTON said:


> Time to get rid of that Forklift anchor and go AC induction mate.
> You don't see us regen guys breaking down on the highway


You say that but my 11 alpha has over 15,000 miles on it now and all is fine.....


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## RIPPERTON (Jan 26, 2010)

I was skimming through one of John Metrics lecture videos and he said if you reverse direction of a DC motor the brushes cock in the holders and the sharp edge digs into the com slots and breaks off in little bits and goes around like a blender.........
Plus they don't do regen..........


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## skooler (Mar 26, 2011)

RIPPERTON said:


> I was skimming through one of John Metrics lecture videos and he said if you reverse direction of a DC motor the brushes cock in the holders and the sharp edge digs into the com slots and breaks off in little bits and goes around like a blender.........
> Plus they don't do regen..........


I believe the alpha is neutrally timed so shouldnt be an issue. Regen is obviously a drawback however an AC system with the same power output would cost 2-3 times more.


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## berlinger (Oct 13, 2012)

Sorry Skooler but I must come in here. I have seen many times this discussion about AC versus DC and biggest argument in DC site is “power level”. Typically, these motors are rated from 20 to 50 KW and it’s true. Fact that you can overload them for couple of minutes has so many underwater stones and it can be problem with Miras motor. He load it with 40-50 KW long time and close to max rpm (130-150km/h in fifth gear means 4800-5500 rpm). It can heat the brushes from friction alone. I am waiting to know what actually is happening with his motor and hope, that it was not a big problem.
I get my Chinese AC 70KW motor/controller combo for same price as Alpha/Soliton cost only plus custom and shipping. Of course, only time will tell what will last longer and be more usable.


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## skooler (Mar 26, 2011)

Hi Berlinger

I don't want to get in to an AC vs. DC debate.... AC usually wins in every area except for bang for buck.

The Kostov 11 alpha is rated for 50KW continuous. Mira was within that power level.

Mine holds 70mph (112kmh) at about 100a at ~230v which is 23KW - well below the motors continuous rating

Mira is running at similar power levels (just faster) so It looks as though the power to go at that speed is about right for the motor.

I suspect the problem is some sort of contaminant getting into the motor rather than it failing due to high power usage - one thing I noted on the alpha was that it isn't exactly well sealed.


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## mira9_cz (Feb 27, 2013)

RIPPERTON said:


> Time to get rid of that Forklift anchor and go AC induction mate.
> You don't see us regen guys breaking down on the highway


This is not normal what I'm experiencing. The worst standard maintenance should be changing brushes each 50 tkm, not doing complete overhaul each 10 tkm. And regen is not really important thing. DC motors are very reliable, compared to ICE engines, but I'm having more troubles with K11 DC motor then with any of my ICE cars! 

As Berlinger noted, I can afford to keep 140 km/h at the highway with my Mazda no problem. Motor should take up to 210A continuous for 1 hour. 210A it takes when I'm driving 170 km/h at flat road, so there is even some reserve. Not that I would desperately needed this power, but it feels good to know that you can beat any of that TDI craps anytime you will decide with a car that nobody even know that drives electric. Please show me comparable AC motor with controller for reasonable price. I promise I won't even repair my Alpha anymore if there will be suitable AC replacement candidate! Now Eldis motivated me a lot to check more about Chevy Volt inverter, which can be very cheap. 

Those guys have some nice oil cooled marine AC motors: http://hpevs.com


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## berlinger (Oct 13, 2012)

skooler said:


> Hi Berlinger
> 
> I don't want to get in to an AC vs. DC debate.... AC usually wins in every area except for bang for buck.
> 
> ...


 *Nope, nope… I just reread Miras tread and find that he has 98 cells, it means 312 volt nominal with 170A is 53 KW electrical power, that actually match with Mazda power consumption graph I have 50 kw for 140km/h. You can drive 100 km/h with 25 kw (that matches too) but extra 40 km/h cost you twice as much power.*


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## skooler (Mar 26, 2011)

Mira,

are you measuring motor current or battery current?

I assume you have the motor limited to 250v in the soliton?


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## berlinger (Oct 13, 2012)

Hi Miroslav, did you find what happen with motor?


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## mira9_cz (Feb 27, 2013)

berlinger said:


> *Nope, nope… I just reread Miras tread and find that he has 98 cells, it means 312 volt nominal with 170A is 53 KW electrical power*


I can not let 312V for K11. Count 250V x 210A for one hour = max power without overstepping declared specs. Yesterday I did not found anybody who would help me to push the car to the workshop, there is small hill. So I do not know yet what happened. 



skooler said:


> Mira, are you measuring motor current or battery current? I assume you have the motor limited to 250v in the soliton?


Yes, I mentioned the motor current, plus I'm limited to 250V in Soliton. The battery current I count from duty % number as advised by Tess.


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## skooler (Mar 26, 2011)

mira9_cz said:


> 250V x 210A for one hour = max power without overstepping declared specs.


That's 52.5KW for one hour continuous... 

How large is your battery? 98*100AH cells is ~32KWH. That doesn't add up - your battery does not hold enough energy to propel you at that power level for that amount of time.

That aside, remember that cruising you where at 210a (52.5KW) but while accelerating you where likely pulling much higher currents. Your motor has not had an opportunity to cool.

After re-reading this and running the numbers I have a feeling your motor has overheated from being run at too high power for too long.


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## tylerwatts (Feb 9, 2012)

Mira
Look here: http://ecopowerpack.com/products.php?CateId=39 for similar AC drives to what Berlinger uses. And you don't need to go direct drive so can keep faster acceleration. 

I agree with skooler that it seems you have over heated your motor. I expect it is the brushes not the motor core. But I will try not to speculate, I hope you find out soon.


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## tylerwatts (Feb 9, 2012)

PS, I would ask that manufacturer to create a special high powered GLMP25 motor with bigger controller for your use. Have a look in Berlinger's thread about our discussion on this.


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## major (Apr 4, 2008)

RIPPERTON said:


> I was skimming through one of John Metrics lecture videos and he said if you reverse direction of a DC motor the brushes cock in the holders and the sharp edge digs into the com slots and breaks off in little bits and goes around like a blender.........


With all due respect, Mr. Metric is full of crap on that one. Maybe he is referring to one particular motor he has with sloppy out of tolerance brush gear, or motors in the use cycle he is prone to subject on them. But generally speaking, commutator/brush DC motors reverse without problem on 100s of 1000s of forklifts in F/R 50/50 duty cycle use everyday with acceptable brush life in the 1000s or even 10s of 1000s of hours. 

Besides, kinda off topic, don't you think? He uses a transmission, right? Probably does not reverse the motor. No indication he has a brush problem here, is there?


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## Old.DSMer (May 18, 2012)

I'll be watching with great interest to see the outcome of your motor inspection. I hope it is something simple and more easily fixed than mine.


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## mira9_cz (Feb 27, 2013)

skooler said:


> That's 52.5KW for one hour continuous. How large is your battery? 98*100AH cells is ~32KWH. That doesn't add up - your battery does not hold enough energy to propel you at that power level for that amount of time.


I should use the word "in theory". Point was that 210A for 1 hour is what they write at the metal sheet at the motor. So it makes me hard to believe that I could do harm with less continuous current in less then one hour time. 



skooler said:


> That aside, remember that cruising you where at 210a (52.5KW) but while accelerating you where likely pulling much higher currents. Your motor has not had an opportunity to cool.


Yes, I know this is happening, but obviously I underestimated what opportunity to cool means. My thinking was when I see motor current 300+ Amps for few seconds and then for 30 minutes I see 160 Amps, I thought that during those 30 minutes @ 160Amps motor should be cooling off the heat that it gained during those few seconds of acceleration. It would make sense since the nominal rating for one hour is 210Amps, which is quite more then 160Amps, but obviously this is wrong thinking.

I can see this seems to be classic lack of experience and excess of confidence situation, I feel stupid  I have this control light which goes on with motor fan at 45C degrees. It never went on when car was moving. I would expected that one of signs of overheating would be the fan trying to cool even when the car is moving. Again this probably is not correct thinking.



tylerwatts said:


> I agree with skooler that it seems you have over heated your motor. I expect it is the brushes not the motor core. But I will try not to speculate, I hope you find out soon.





skooler said:


> After re-reading this and running the numbers I have a feeling your motor has overheated from being run at too high power for too long.


Well what can I say guys, I feel stupid. I still do not understand it, it was 7C degrees outside. Car had driven 8000 km much harder style last Autumn before it failed. And now it fails by heat issues after only 200 km of normal highway driving. It does not make much sense to me.


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## mira9_cz (Feb 27, 2013)

Old.DSMer said:


> I'll be watching with great interest to see the outcome of your motor inspection. I hope it is something simple and more easily fixed than mine.


Thank you, I hope too. 

Today I managed to get car to assembly pit and looked under the brush cover. I could not remove it completely because of front axle - I would need to lift the motor little bit and for this I need second person, which was not available. But anyway good news is that commutator seems to be all nice and shiny! The brush holder is firm in it's position, rivets holding, so vibrations made no harm yet. In the car I can not check all the brushes. But those at the bottom which I could check were looking fine. 

Now when I know commutator is o.k. I think the theory is that wires got loose again in some of the brushes, most probably by too high continuous current = heat. Turning at the roundabout pulled them out while straight highway driving kept them in place. It might be, right?

It still does not make sense how it could survive 8000 km and then fail after 200. Probably brushes are much much more sensitive when they are new. Last year I had driven about 500 km first before trying the car at the highway for first time. Hard to believe those 350 extra kilometers made such a difference.

Car is loaded at the trailer behind my van again, I hope next Wednesday I will have chance to remove the motor and disassemble it to see more.


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## mira9_cz (Feb 27, 2013)

tylerwatts said:


> PS, I would ask that manufacturer to create a special high powered GLMP25 motor with bigger controller for your use. Have a look in Berlinger's thread about our discussion on this.


Thank you very much for the tips! I admire Berlinger's solution, I think this is far most advanced electric RX-8 yet build. I read whole thread several times already and raped Berlinger's DIY Message box quite a lot too  
But first things first - motor running again, preventing further motor failures, PS and Inst. panel, homologation stuff. And then I can think about more. I can not get too excited in new projects when I'm fighting with basic issues.



berlinger said:


> Sorry Skooler but I must come in here. I have seen many times this discussion about AC versus DC and biggest argument in DC site is “power level”. Typically, these motors are rated from 20 to 50 KW and it’s true. Fact that you can *overload them for couple of minutes has so many underwater stones* and it can be problem with Miras motor. *He load it with 40-50 KW long time and close to max rpm (130-150km/h in fifth gear means 4800-5500 rpm). It can heat the brushes from friction alone.* I am waiting to know what actually is happening with his motor and hope, that it was not a big problem.
> I get my Chinese AC 70KW motor/controller combo for same price as Alpha/Soliton cost only plus custom and shipping. Of course, only time will tell what will last longer and be more usable.


And here we go! It makes sense that RPMs also influence heating of the brushes. I never thought about this before. I usually try to maintain as high motor RPM as possible by using lower gears, "trading" less Amps for more RPMs this way!


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## berlinger (Oct 13, 2012)

I reread what I am wrote and am a little shame now. My motor is 30kw nominal, Alpha is 55 kW, and it is a big difference. Yes DC is more powerful for same price.
Info about brush heating from rpm comes from Kostov (he is here, I forgot his nick) when I ask about max rpm for my first project. It was a SUV with 10” motor connected to slow speed gearbox. It was too slow in LOW position (max 80 km/h) and too weak in direct drive and I ask him how far I can go with rpm. I temporary lose interest about it when start my Mazda conversion, but “must” finish sometimes.


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## mira9_cz (Feb 27, 2013)

Today we took the motor out of the car and examined the problem carefully. It is not brushes problem after all, they all looks still like new. The problem unfortunately is the commutator. With limited access under the car I did not noticed two spots with the damage. Check it below. 










Now I measure short circuit between any pad of commutator and the chassis of the motor. The insulation of the commutator is obviously dead. So I need new rotor. 










I spoke with dad's friend who used to repair motors for living and this is what we found out that might be my case. My K11 Alpha was not well made, the motor was unbalanced from the beginning and I did not recognized how bad it is. After 8000 km of vibrations the brush holder gave up, which caused brushes to touch the commutator unequally (as you can see in last picture). This caused excessive heat of the brushes, which damaged the commutator, but not only contact surface, but especially the insulation. Eventually the brush wires sparked inside of the motor and this caused fatal failure. After repairing the commutator appeared to be fine, but excessive heat from first failure took it's price on commutator insulation, which now failed completely immediately after first serious duty.

Mr. Nakev (Plamenator) told me that it is very likely that rotor will fail again. He did not shared the reasons with me, but apparently he saw my pictures that commutator in this shape is possibly damaged behind being repairable.


This is how it looked like at the lathe after first failure, last 10 seconds shows everything. Machinist had to take 0.6 mm of material so the knife would start machine all 360 degrees of the commutator: https://www.youtube.com/watch?v=91ATIECHRbY

And for reminding here is how brushes looked like after first failure.


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## major (Apr 4, 2008)

You're right, the armature is in bad shape. I suspect that there is an armature coil which is damaged further in the core and the short (or ground) is not actually in the commutator. Either way, a new armature or factory rebuild is needed. Have you contacted Plamenator?


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## Old.DSMer (May 18, 2012)

Sorry to hear of your problems. Very disappointing. I'm hoping to have mine back on the road within the next week. I will be very cautious and perform short distance tests to reduce chances of failure far from home. I also have 2 thermocouples mounted inside so I can keep very close watch on the temperatures. I hope you are able to get the repairs done quickly. I wish you the best of luck!


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## berlinger (Oct 13, 2012)

It’s sad to hear how big is your motor problem. This means that you were in parking again for much longer than expected. What solution you see for rotor? Will repair locally or try to by new one?
Do you have some progress with power steering? Do you finally get yours working or motor cancel all your experiments?


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## mira9_cz (Feb 27, 2013)

Thanks guys for your sympathies. I'm still waiting for reply from Mr. Plamen. If he will offer me new rotor for special price as he did last time, I will buy new rotor, put it at the lathe to verify if it's balanced correctly and install it as soon as possible. Meanwhile some interesting opportunities to go AC showed up, but priority is to repair existing drivetrain. 



Old.DSMer said:


> Sorry to hear of your problems. Very disappointing. I'm hoping to have mine back on the road within the next week. I will be very cautious and perform short distance tests to reduce chances of failure far from home. I also have 2 thermocouples mounted inside so I can keep very close watch on the temperatures. I hope you are able to get the repairs done quickly. I wish you the best of luck!


Good idea with second temp sensor. The original thermistor is mounted at the brush holder by same screw that holds one of the brush wires to conductor. I was thinking putting second thermistor closer to the brush itself at some custom holder, but we will see.



berlinger said:


> Do you have some progress with power steering? Do you finally get yours working or motor cancel all your experiments?


Last week I managed to buy spare PS ECU and also motor cable loom which I unfortunately sold with ICE. Mazda is at workshop again, so testing RPM signal with new PS ECU will have to wait. But at least now I'm spending my evenings playing with the loom, taking reverse light and neutral gearbox position sensors out of sticky cable mess. I would like to locate RPM sensor there as well, to try simulating RPM signal to "boot" PS ECU the analog way as you told me to. What should I look for? Crankshaft position sensor?


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## eldis (Sep 3, 2013)

mira9_cz said:


> ... I would like to locate RPM sensor there as well, to try simulating RPM signal to "boot" PS ECU the analog way as you told me to. What should I look for? Crankshaft position sensor?


Yea, it should be a crankshaft sensor (or a hall sender or thousand of different names it probably gets..) Anyway it is a three pin connector usually mounted on the bottom of the engine. It will have pins +5V/12V, Hall effect out and probably a ground. Signal will be something like 58 teeth wheel + extra 2 spaces to make 60 'ticks'. (you can emulate it with an arduino). I would say that using a 5V digital signal to emulate it could work.

If you don't know for sure which wires, you can try to track it on your instrumentation cluster side.


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## mira9_cz (Feb 27, 2013)

eldis said:


> Yea, it should be a crankshaft sensor (or a hall sender or thousand of different names it probably gets..) Anyway it is a three pin connector usually mounted on the bottom of the engine. It will have pins +5V/12V, Hall effect out and probably a ground. Signal will be something like 58 teeth wheel + extra 2 spaces to make 60 'ticks'. (you can emulate it with an arduino). I would say that using a 5V digital signal to emulate it could work.
> 
> If you don't know for sure which wires, you can try to track it on your instrumentation cluster side.


Thank you Eldis. I dare to say that after all this stuff I remember RX-8 Electrical manual more then any other literature known to me  But Berlinger already verified analog simulation of RPM signal successfully, so he can confirm if it is eccentric shaft position sensor (Y/B and Y/R wires) or something else 


Still no reply from Bulgaria :-(


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## berlinger (Oct 13, 2012)

Yes, two yellow wires are correct ones. Sender is with magnetic core, but I didn’t test voltages what it generates.
Teeth plate is complicate, look in this:
http://www.rx8club.com/attachments/...application-fi-renesis-rx-8-trigger-wheel.jpg


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## mira9_cz (Feb 27, 2013)

Motor finally arrived repaired from Bulgaria this Monday, so I installed it in at Tuesday immediately. What can I say, it is less noisy then before, but some vibration is still there in certain RPM without load. I hope it will perform better this time. 

Whole action took nearly 2 months. I really hope I will not see picture like below ever again. This was last time I installed this motor into my car.


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## skooler (Mar 26, 2011)

Good to see it going back together. Let us know how you get on


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## MCatlos (Oct 22, 2010)

I saw that you use BMS123 in your car. Have you tested the BMS-watch,
Android Apps for BMS123 ?


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## Duncan (Dec 8, 2008)

Hi MCatlos
You are getting very close to being banned for scamming
Please don't use this forum to try and sell stuff 
Use the correct forum


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## mira9_cz (Feb 27, 2013)

Actually Martin is probably offering quite good product, if it work  I have exactly the problem with EM noise he says he solved. I'm so close to get rid of BMS123 in favor of different BMS, and Martin's product is the last hope right now. I already sent him PM. 

I have stopped driving Mazda last Saturday with first snow, and also salt at the roads. Soon I hope I will find a some time to share with you what is new.


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## mira9_cz (Feb 27, 2013)

Martin already contacted me through GWL, but I was too busy to answer. Here is what he sent to me: 

_____________________________

From the beginning I was using the PC to monitor the BMS data. But the PC very often lost connection to BMS due to disturbancy from the motor
controller. The PC software is very sensitive to this type disturbancy,

Now I am using a smart phone to monitor the BMS data. I have connected a
Bluetooth serial interface module, HC-06, to the BMS master.

My friend Östen has developed an Android App, BMS-watch. The App fetches
the relevant data from BMS master and present them at the phone display.
The GPS in the phone is used to present the speed, distance and calculate
the remaining distance. The disturbancy from the motor controller is "filtered" in the App.

I was using the BMS-watch the whole summer and I am very content with it.

If you want to test the BMS-wach you can load the USB prototype from

http://www.oskarsson.se/Android_apps/

Information about my 2CV, Elenka, you find at

http://www.evalbum.com/4967/ or http://illcittrasektionen.citroenklubben.se/

_____________________________

I lived under impression that monitoring / balancing cell modules themselves are catching the EM noise, not the USB interface. I think we solved it here in this thread already before. This what Martin wrote gives me certain hope that I was wrong. 

The thing is that BMS modules will obviously stop communicating anytime I push the throttle. BMS modules are blinking, and they stops. This made me think communication is disturbed and this causes the PC software to stop showing certain values. But if the USB is catching the EM noise and this is the reason why BMS stops communicating with modules, then Martins product seems like a solution. 

Martin, if you will read this, can you tell me - when you experienced PC software not working, what about current and SOC readings? These works for me normally, but I don't get no voltage and temperature info. Is this the same case you are describing?


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## MCatlos (Oct 22, 2010)

Duncan said:


> Hi MCatlos
> You are getting very close to being banned for scamming
> Please don't use this forum to try and sell stuff
> Use the correct forum


I am not sell anything. The app "BMS-watch" is free to download.


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## Duncan (Dec 8, 2008)

MCatlos said:


> I am not sell anything. The app "BMS-watch" is free to download.


Excellent!

But please mention things like that 
- our "Spam detection" reflexes are pretty hair trigger - 
we get a LOT of bloody spam!


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## MCatlos (Oct 22, 2010)

I had the same problem with disturbancy. It took one year to find the source to it 
and fix it.
I can tell you about my experiences with this problem and solution outside this forum. You can contact me at Skype. I was born i Bratislava and my Slovak language is still better than English.


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## mora (Nov 11, 2009)

Did you ever install STP networking cable between BMS master and modules? I read you used some special CAN cable and were about to replace those using UTP cables. We have used same BMS and found it very prone to noise. Experienced the same problem of gently touching the throttle and BMS going crazy also. Note that UTP is Unshielded Twisted Pair and STP is Shielded Twisted Pair. Use STP all the way. It should be cheap anyway.

Every battery bank needs those IN and OUT modules. Even if batteries are 30cm away from each other. These modules have to be connected using STP cabling. "Regular" cell modules don't need STP between them but keep the wires as short as possible.

I think using external software to filter noise doesn't help at all if your BMS master doesn't receive info from BMS modules correctly.


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## MCatlos (Oct 22, 2010)

I am not using the STP/CAN cables any more because these cables caused my BMS problems. 

At the begining I used only the UTP cables. Both the monitoring and balanced charging worked perfectly. The “electronic dashboard “ on PC showed the correct figures.
After a month, I noticed that the cell temperature and cell voltage would sometimes momentarily drop. Also the communication between PC and BMS was interrupted.
So I replaced the UTP cables to IN/OUT modules with CAN. But this change does not hepled,. Therefore I replaced the other cables to BMS with CAN cables. The cables were grounded at both ends and there are small ferrite coils on all wires at both ends. I placed also the BMS master board in a metal shielding box. The special CAN cable I used was a "Shield Twisted three leader cable".
But none of these of these measures helped. As soon as I touched the accelerator pedal the communication between the BMS master and the cell modules were interrupted. 
With help an EMC expert I found that the disturbancy (15 khz), in my car, come from the Curtis motor controller and not from DC motor. This disturbancy goes via the battery cables into the IN and OUT modules and then from the OUT module to the BMS master. 
When I replaced the CAN cable from the OUT module with UTP cable the disturbancy problems ceased . Both the monitoring and ballancing works perfectly now. 
I don't´know if it was the third leader or the shielding and grounding of the CAN cable that caused these problems. But in this case it is *unnecessary* to have the shielding because the disturbancy is allredy inside the cable. 
According to the article “Shielded and unshielded twisted-pair cable revisited” it is difficult to build the system with STP cables. The recomendation is use UTP cables. 
The BMS-watch doesn't filter the EMC-noise but it handle communication to BMS without any interrupts. 
I think that the PC-program interrups the communination with BSM master when it receive some "corrupted data" from the BMS. 
The BMS-watch comunnicate wih BMS master regadless “corruped data”. It sends continuously the data request string '$' to the BMS master. The received data are then translated and presented on the mobile screen.


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## MCatlos (Oct 22, 2010)

mira9_cz said:


> Martin already contacted me through GWL, but I was too busy to answer. Here is what he sent to me:
> 
> _____________________________
> 
> ...


Miroslav, I get all the information (current, SOC, voltage and temperature with cell numbers) both with loading and driving. I assume that you get all this info only during charging.


If you are using STP (Shielded Twisted Pair) then you should replace the STP cable from OUT module with UPT ( Unshielded Twisted Pair) cable. I hope that this change of cable solve you problems as it did for me.


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## Digix (Apr 27, 2010)

berlinger said:


> It’s sad to hear how big is your motor problem. This means that you were in parking again for much longer than expected. What solution you see for rotor? Will repair locally or try to by new one?
> Do you have some progress with power steering? Do you finally get yours working or motor cancel all your experiments?


Hey guys! just some info that would be usefull for anyone converting a Mazda RX8.

The ECU must be removed and following CAN messages must be simulated to have no errors on display, control cluster, etc. The stability control, ABS works with this setup! Tested on Mazda RX 2004 


```
201 38 A8 FF FF 3A 2B C8 81    // 0,1 bytes RPM; 4 - Speed (26=0;3F=65; 4F=106; 5F=147; 6F=189)
420 6B 23 C7 00 00 00 61 81    // 0 byte Temp (non linear) (5B-0%; 60-10%; 68-25%; 98=50%; 9E-75%; A4=100%) Fault codes: 01-ok; 00 error: 4 byte: Oil pressure, 5 Check engine, 6 battery charge
215 02 2D 02 2D 02 2A 06 81    // Some ECU status
231 0F 00 FF FF 02 2D 06 81    // Some ECU status
240 04 00 28 00 02 37 06 81    // Some ECU status
250 00 00 CF 87 7F 83 00 00   // Some ECU status
200 00 00 FF FF 00 32 06 81   // EPS doesn't work without this
202 89 89 89 19 34 1F C8 FF  // EPS doesn't work without this
```


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## pavel174 (Mar 7, 2012)

Hello, the last holidays. I solved the problem with the steering rack is much easier to set it on the motor shaft gear and set the sensor (below fasten link to Russian Forum electric)
How it all works for me. You sit down in the car you turn the ignition key, waiting to load when the controller 1 soliton then just slightly depress the accelerator pedal to the engine motor alfa k11 began its rotation thus it gives the controller ESU vehicle that the motor is running and the steering rack will run until not switch off the ignition. It's very simple works. I have so go 12,000 km.
http://electrotransport.ru/ussr/index.php?topic=22327.0
The forum has some of my videos


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## mfox (Feb 3, 2013)

Hello, I Just read all posts . Great conversion!!.  , last month i finished conversion on old Opel Kadett to electric. Maybe you saw it . I'm now so happy and impressed how nice is to drive electric. I'm total addicted to EV conversion. Im also having BMW E60 530 D. In the future I want him electric. I was looking wich motor and controler to take. I also decided to buy K 11 , but after your problems. .. don't know. .. I wanet to put i directly without gearbox. What do you think is i possible to drive this motor without gearbox? ?? And is good because of weight. . You can put more batteries. .


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## mira9_cz (Feb 27, 2013)

Digix, Pavel: Thank you both for your messages! I'm about to get back to this topic very soon, too much external projects right now. I will sure test both approaches and will let you know!

mfox: Congrats to your conversion! Sure, it is possible to run K11 without gearbox, in light car it makes much more sense then using the gearbox. But be careful, the more cells you will add the less sense it makes, because of rising weight  But if you are not seeking for electric sport car, then definitely go for it. Also I recommend you to visit thread about hybrid gearboxes: http://www.diyelectriccar.com/forums/showthread.php/hybrid-transmissions-diy-e-v-futurei-154570.html This is definitely the path my project will follow. Installing DC drive today does not make so much sense as few years back when I started my Mazda conversion. 

Sorry to everybody I'm not updating my thread very often, but it does not mean I'm out of the business. Situation is rather opposite, which gives me less free time, I'm sure everybody who mean E.V. business seriously are in the same position


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## mfox (Feb 3, 2013)

Tnx  
That's great! I thought that this motor and controller is wery difficult to make them work in conversion. The price is also wery good . I would also like to buy one for my next conversion.  
I saw BMW 330Ci conversion whit this motor , but running it is not so easy and I don't like so high voltage... 650V is to much... I wouldn't go more than 300V DC nominal ... Don't know if is possible to reach 200kw with 300V..


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## sinisbehindyou (Jan 22, 2016)

Digix said:


> Hey guys! just some info that would be usefull for anyone converting a Mazda RX8.
> 
> The ECU must be removed and following CAN messages must be simulated to have no errors on display, control cluster, etc. The stability control, ABS works with this setup! Tested on Mazda RX 2004
> 
> ...


I recently tried using this code on a RX-8 im working on and it gets the speedo and rpm to move but doesnt turn off the Anti- Theft and the power steering .also the EPS works only for one second then stops. Hopefully its something easy to figure out !!!!


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## berlinger (Oct 13, 2012)

I will newer recommend this solution for somebody without some future comments. At first moment, it looks good, but has some underwater stones (of course). ECU is central computer for this car and if you disconnect it, you lose wehicle speed signal at all. Man who send this forget to say that hi is building their own board that calculates speed from motor rpm (it is direct drive car) and it is still not finished…..
Power steering unit need engine rpm signal just once, then it goes ON until you switch ignition of. You can try to put ECU back in place and simulate rpm in analog way using original signal sender. It does not need very accurate signal input here, just put it close to some rotating stuff. If you get your PS to work in that way, then you can go deeper into CAN. With ECU in place you can use diagnostic tools too.


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## razoor1144 (Jul 15, 2014)

Hi All! 

Somebody have CANBus log from RX-8 with Wankel engine, and can send me on email ? my mail : [email protected] 

Thanks !


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## skooler (Mar 26, 2011)

What exactly is it that you need? Its quite a busy bus

Sent from my SM-N9005 using Tapatalk


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## razoor1144 (Jul 15, 2014)

Thanks for your response ! 


I need exactly frames CAN bus are responsible for controlling the instrument cluster, because I want to swap cluster from Mazda RX-8, to another Mazda without CANbus. All the ID that I found on this forum do not activate the odometer. Speed, engine speed, temperature, lights etc. work properly. Trip A / B shows all the time 0.0 and main trip not count. I think, that I need some additional signal, probably from ABS, which speaks about the fact that the car is moving. Therefore I need a dump CAN bus a few seconds, preferably while driving. I will be able to send a data packet to the cluster and excluding unnecessary information.


skooler said:


> What exactly is it that you need? Its quite a busy bus
> 
> Sent from my SM-N9005 using Tapatalk


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## skooler (Mar 26, 2011)

Where abouts are you located? Its not exactly an easy task to sniff these. I have a petrol and an electric rx8 for testing.

Sent from my SM-N9005 using Tapatalk


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## razoor1144 (Jul 15, 2014)

I from Poland, I use CANHacker aplication and arduino with canbus shield. In this forum I found that user mira9_cz use recorded data from Rx8 and cluster work OK with trip


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## mira9_cz (Feb 27, 2013)

Hi everybody, it is time for an update after one year. Mazda is all right, this year it had driven 35 thousand kilometers. What else to say. Power steering is still not working. I have done everything as everybody else with electric RX8 did, but no results. I got desperate so I think in August 2016 I spent whole day with CAN-Bus professional Company which does CAN development for living. We compared ICE RX8 with my car, done everything together again as I did many times before. No result again. They liked my car and my enthusiasm, so I did not have to pay 10 x 92 EUR hour rate, but I would rather reached some results. Now my opinion is that there has to be something wrong with steering rack.
I'm still very excited about replacing my DC motor with Lexus gearbox. Eldis has his UMD drive ready and I have Chevy Volt inverter purchased, so no barriers anymore except being busy. Wish me good luck to move this project forward soon.


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## mfox (Feb 3, 2013)

Hello , good luck with AC power system , but I still don't like such high voltage..


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## puff (May 8, 2017)

Hey, guys! 
Have you managed to fix the odometer thing? 
Could anyone post the canbus log from the running car?


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## mira9_cz (Feb 27, 2013)

Late but here it is. This is few minutes of wankel RX-8 driving: http://like.cz/mix/_stabilni/mazdathread/sample_log.log


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## mira9_cz (Feb 27, 2013)

Few weeks ago I saw some Wankel powered RX-8s at local race track. I checked them under the bonnet, of course, and I noticed there is strong fuse for electric power steering, directly at the battery +pole. Some guys had air-boxes replaced by KN filters, starting battery in the trunk and other modifications, so I could trace the cables and.. Of course I don't have this harness in my car anymore!!! I feel like a fool now. I have tried different CAN-Bus voodoo stuff, establishing separate CAN networks, developing HW gateways to filter messages between CAN lines, changing power steering ECU, checking wires to steering rack, steering wheel position sensor and tons of other stuff, but I simply did not realized that electric power steering also need to be powered!! Somehow I became 100% sure that this is solved by Mazda main fuse box, I completely forgot that it was powered from +pole of starting battery directly. Power steering ECU was speaking to me over CAN and I didn't suspected there is no power for steering rack itself. OK, stupid me. I know what I must do now


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## piotrsad (Apr 14, 2014)

Hello Mira, 
any update on the project after so long time ?

best Regards 
Piotr.


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