# Need your input on my new project - FFR e-GTM



## Hugues (Jul 13, 2014)

Hi guys,

Now that my electric motorbike is up and running (see www.zvexx.com), i'm thinking about my next major project.

I'm planning to buy this kit car from Factory Five:
http://www.factoryfive.com/galleries/gtm-supercar/sema-2014-gtm/

and build it with an electric drive train.

Final weight should be around 1150 kgs, i would like a 0-60 mph acceleration as close to 3.0 seconds as possible, street legal.

could you suggest a motor, controller and battery pack for this kind of performance ? Don't need crazy top speed, 160 km/h is sufficient. Range should be above 150 km at 100 km/h.

My simulation shows that i can fit in 29 kwh of Nissan LEAF batteries, so 60 modules, that's about 0.027 cubic meter for the volume you see in orange in attached drawing. WOuld like to run at around 200 volts. Battery, motor and transmission are all rear mounted.

I'm planning to use a transmission, for now it's a Porsche G50 (1st gear 3.154, 5th gear 0.861, Ring and pinion 3.44, in pink in attached drawing), but i'm opened to your proposals.

I don't have a lot of longitudinal space for the motor, in yellow, at the moment i'm showing an Emrax 268. I've got 165 mm between face of transmission and battery pack, so i'm looking for a thick cake rather than a long log 

Tires 335/30 18

I attach my latest EVdesigner spreadsheet if ever,

Budget is opened for the moment (until my wife hears about it )

Awaiting your ideas,


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## dain254 (Oct 8, 2015)

I've seen recently on this forum that someone has been able to achieve control of a drive unit from a Tesla - if you are looking to build this with parts salvaged from current EV's that is likely what it would take to achieve the performance you are looking for. Tesla Modules can also be modified to increase their voltage from 24 to 48... so a person could keep the voltage the same with half of the batteries (8 modules?). I've considered starting with a GTM, but like the 818C even better since it is smaller and lighter! In the 818C I believe your performance figures could be met with a pair of motors off the shelf assuming a person can make a small efficient gear-train for them - or simply adapt them to feed a differential, 1 speed!


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## Yabert (Feb 7, 2010)

Yea, Tesla drivetrain (front or rear) can do a good job in your case.
And the member with probably the most experience with tesla drive train is near you (Geneva)
http://www.diyelectriccar.com/forums/showthread.php/fun-tesla-motor-152890.html


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## Kevin Sharpe (Jul 4, 2011)

I would recommend you have a chat with Anne Kloppenborg from New Electric in Amsterdam (DIY Electric user name Ams_AK). They are converting a FFR 818 and have done a lot of work with Hamming Performance the European distributor.

They have some 818 related video's on YouTube;

https://youtu.be/YGr4DgTs8qU


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## Hugues (Jul 13, 2014)

thanks for your input guys,
nice to know there are people around to connect to,
i will contact Eldis in Geneva, it's just one hour away, although the Tesla drivetrain does not seem like a week-end hack job as i can gather from reading Eldis's thread. We'll see, but it seems way too wide for my frame. Need to measure. Although Tesla adds to the cool factor.

I'm already in touch with Freek at Hammink and will ask him about the FFR 818

Yabert, i was born near Quebec, Anc.-Lorette actually.

thanks guys, i'm still open to other proposals/challenges from other members !


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## minispeed (Jun 30, 2013)

Depending on how long it will take you before you buy batteries you will probanly be able to source a 2016 leaf 30kWh pack by then so equal capacity in less modules. Switching to an 818 would prob offset the cost of a newer leaf pack and an 818 with a leaf motor and the 200kW inverter/controller that has been posted on here would be good. You may even be able to use 2 of them in a gtm.

I myself have thought about the factory five kits, there are some electric 818s and at least 1 daytona. Thats the one i'd pick.

I think a leaf based kit would be sweet. The battery pack could probanly be used as is in the chasis.


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## Hugues (Jul 13, 2014)

Thanks minispeed, I fell in love with the GTM, that's my build or nothing.

I'm not in a hurry to buy the batteries, any idea where I can buy a new 2016 Leaf pack, I need enough to deliver 300 kW. Hybridautocenter.com ? That's where I bought the one for my motorbike.


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## minispeed (Jun 30, 2013)

hybridautocentre.com sells packs that come from wrecked cars so for that it's a bit of a waiting game...

I'm sure they'll provide packs as they become available.

I just looked on http://www.car-part.com/ and didn't see any 2016. Since the sales were lower than in 2015 they won't have as many of them. Plus the 2016 SV and SL got the larger battery the S was still the same as a 2015 car.

From what others have said about power vs range if it's max power you want you're better off with a volt battery than a leaf battery.

I took a look at the FFR frame for the GTM, you may also be able to fit a FWD based transmission in there with a warp/kostov motor. You also may be able to fit a Porsche transaxle in backwards... or better to say the way Porsche designed it. It shouldn't make it feel like a rear engine car with a 60-100kg motor on the back when you have 200kgs+ of battery where the V8 would have been. The transaxle would still intrude into the old engine bay (I assume the new battery bay) but it wouldn't take up as much room as the motor would. You also wouldn't need to leave space around it for service access and or cooling.

Going back to your battery power requirements with my stock leaf and 22kWh available I can do my 140 mostly highway (95-98km/hr speed) drive on a single charge when conditions are good. With an 1150kg weight you'd be about 350kg's lighter and your aero would be much better. Tire rolling resistance would probably be more but I doubt it would overcome your aero advantage.

I think it's safe to say that you could get your range target with a 20kWh (usable) pack to save on weight. Adding weight to get your range makes your goal of 0-60 in 3.0 more difficult/expensive. Instead of just focusing on power to get there I'd make sure you get a transmission with an LSD to ensure that you can take full advantage of the instant torque.


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## Hugues (Jul 13, 2014)

Thanks minispeed

As for the position of the G50 transaxle, you mean like I show in my opening post ? There is less height at the back of the frame so better for the tranny to be there and keep the higher height part of the frame (behind driver) for batteries no ? I prefer to have my battery stacks laying on the floor of the frame than on top of other components, because then I have to modify frame.

As for the size of battery pack, seems my motor will need 300 kW for this kind of performance. For a Leaf pack to provide this, peak, that's 72 modules at least. Then range will be more.

Thanks for the tip on LSD, seems I can find a Porsche G50 with LSD or buy the part.

Thanks again for your feedback.


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## ken wont (Jul 6, 2016)

http://thefactoryfiveforum.com/showthread.php?3316-which-Trans-on-the-GTM


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## minispeed (Jun 30, 2013)

Hugues said:


> Thanks minispeed
> 
> As for the position of the G50 transaxle, you mean like I show in my opening post ? There is less height at the back of the frame so better for the tranny to be there and keep the higher height part of the frame (behind driver) for batteries no ? I prefer to have my battery stacks laying on the floor of the frame than on top of other components, because then I have to modify frame.
> 
> ...


What I mean by the position is to mount the transmission with the clutch to the rear of the car and mount the EV motor in the space normally taken up by the tail of the transmission. So it would make it a rear engine car but with the smaller EV motor it wouldn't make it handle like an ICE rear engine car especially with batteries in the old ICE position.


Did some digging on the G50 transmission and found out there are 2 boxes, long and short. FFR link in the previous post says both will work.










So based on you saying you'd have 165mm from the transmission to fit a motor that means you have about 365mm from the cv joints. If you used that transmission as a rear engine you would need about 450mm est with a long case transmission. I can't find info on how much shorter the short is but if it's anything over 90mm shorter there's a good chance it will let you fit the batteries in like you posted.

This page has pics of the short and long boxes although it's hard to get a visual of how much shorter it is.
https://californiamotorsports.net/pages/porsche-g50-5-speed-transaxle-specifications


Short:









Long (same as the pic with measurments):









Using these 2 pics I'd say there probably is enough room to mount an EV motor behind the axle:



















This link shows some pics of the engine open with the body on, again looks like there's good room behind. You would probably have to create a custom rear diffuser though.

http://www.hotrod.com/articles/0611kc-factory-five-gtm/#0611kc_03_z-factory_five_gtm-engine


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## minispeed (Jun 30, 2013)

PS If you can use an audi unit look how far forward the axles are.


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## bigmouse (Sep 28, 2008)

Transmission from a FWD A4/Passat would be the way to go. Same as those shown above, but without the output for the rear wheels.









From here: https://www.ecstuning.com/b-genuine-volkswagen-audi-parts/transmission-assembly/01x300044ex/


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## Tomdb (Jan 28, 2013)

I will just leave this here.

http://electrek.co/2016/08/08/all-electric-818-kit-car-tesla-drive-unit-chevy-volt-battery-packs/

https://www.youtube.com/watch?v=2OITr1kTutQ

FF 818 btw has a smaller engine bay then a GTM


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## Hugues (Jul 13, 2014)

Allright,

been playing with numbers for the past few weeks and also progress my CAD model.

- I can fit 72 Leaf modules in 4 nice stacks of 18. All behind the driver and in front of the motor and tranny. There is no space for much batteries in the front of the frame, i've checked.
- So that's nearly 300 kw peak (295 to be precise) and 35 kwh.
- Using EVdesigner, picture attached, i need the maximum torque i can get to reach my objective of low 3.0 sec for 0-100 km/h.
- I would use the new Emrax 348 (1'000 N-m and 300 kw peak power, specs attached)
- Freek from Hammink recommends the GT2 transaxle from a Porsche 911 with LS to handle that much torque and the clutch kit, 6 speed
- the max rpm of the 348 is 3350 rpm, i could run it at around 270 volts
- I would need the first 4 gears of the tranny to get to 100 km/h in 3.3 seconds (might be able to start in 2nd gear and shift to 4th, don't know)
- then i could reach a max speed of 160 km/h using 6th gear, which is more than enough for the roads we have here with multiple radars.
- EV designer gives me a range of 216 km at 100km/h, which is more than i expected
- total weight is 1233 kgs, 112% of a gas engine GTM, probably less than 112% as i did not count all the various small hardware i won't need getting rid of ICE, and also not taking gas tank weight and gas.

Please let me know if that does not add up.


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## Duncan (Dec 8, 2008)

Changing gear three times and getting 0-100Kph in three seconds
I don't think that's possible - the gear changes will simply eat too much time

Most fast electric cars have a very small number of gears (1) - are you sure that you will need to change gear?
With maximum torque available at zero rpm?


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## Hugues (Jul 13, 2014)

Duncan said:


> Changing gear three times and getting 0-100Kph in three seconds
> I don't think that's possible - the gear changes will simply eat too much time
> 
> Most fast electric cars have a very small number of gears (1) - are you sure that you will need to change gear?
> With maximum torque available at zero rpm?


Yes you're right, i was thinking the same after posting. On paper looks like i could start in 2nd gear and shift to 4th directly, or maybe start in 4th and stay there. Seems weird, but the motor has so much torque, more than the wheel friction can handle.

I need a transmission with this motor because max rpm is 3500, that limits me too much in top speed. I read the thread about pros/cons of tranny and for my first build i would like to have it, easier to mate the motor through a clutch. Where i live there are many hills and the tranny will help there too. And the GT2 is not that heavy (180 lbs ?) and i have the place. Other 2 speed gearboxes i've seen, or differentials are sometimes heavier than this.


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## riba2233 (Apr 29, 2015)

You can use only one gear, high one, one you want for top speed. Your motor has 1000 Nm  And that multiplied with final gear ratio... It's just too much on the wheels  Or, use one motor for each rear wheel with single reduction stage (you can use two smaller motors).


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## Scooter M (Apr 16, 2014)

Hugues said:


> Hi guys,
> 
> Now that my electric motorbike is up and running (see www.zvexx.com), i'm thinking about my next major project.
> 
> ...


3 second car, 400hp. Here you go:

Motor:

http://www.evwest.com/catalog/produ...ucts_id=300&osCsid=4hun3jrjsvpgrdmj5gloks0me2

Controller:

http://www.evwest.com/catalog/produ...ucts_id=262&osCsid=4hun3jrjsvpgrdmj5gloks0me2


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## Hugues (Jul 13, 2014)

Scooter M said:


> 3 second car, 400hp. Here you go:
> 
> Motor:
> 
> ...


Interesting,
but 18'000 usd for the motor only.
The Emrax 348 should be around 11'000 usd.
It's also 81 kgs versus 348 at 42 kgs, and much less volume for 348.
So i'm not sure of the benefit of going for this motor ?


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## Scooter M (Apr 16, 2014)

Hugues said:


> Interesting,
> but 18'000 usd for the motor only.
> The Emrax 348 should be around 11'000 usd.
> It's also 81 kgs versus 348 at 42 kgs, and much less volume for 348.
> So i'm not sure of the benefit of going for this motor ?


I came across the Emrax motor line over a year ago. Very impressive. Is the 348 ready to ship? As of December, it was in testing. What voltage were you planning on working with?

You may want to look at what you are planning to use as a transmission and the max RPM spec of the 348.

I also think you are a bit off with your weight calculations. You will have almost 260kg of battery alone.

Please reply.


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## Hugues (Jul 13, 2014)

Scooter M said:


> I came across the Emrax motor line over a year ago. Very impressive. Is the 348 ready to ship? As of December, it was in testing. What voltage were you planning on working with?
> 
> You may want to look at what you are planning to use as a transmission and the max RPM spec of the 348.
> 
> ...


Roman at Emrax told me recently he was expecting to finish the tests on his new 348 this autumn.

I'm planning to use 72 Leaf modules, paired by 2. Charged at 4.1 volts per cell, that's 295 volts out of the charger. Roman told me to use the low voltage Emrax and use 2 controllers to get the full power out of the motor.

As for the rpm of the motor and transmission. I did check and used the EV estimator for that, in 4th gear i can reach 108 km/h, and in 6th gear i can reach 160 km/h. That's enough for me.

As for the weight, i did my calculation, although i can make mistakes. Here's how it goes, roughly:
weight of LS7 ICE motor used in GTM	206	kgs
weight of 72 LEAF Gen2	266.4	kgs
Controller 8.5	kgs
Orion BMS	2.5	kgs
EMRAX 348	42	kgs

Brut difference	113.4	kgs

battery and controller box	20	

Net difference	133.4	

Weight of ICE GTM	1100	kgs


So electric GTM would be roughly 1233.4	kgs

And i'm not counting other ICE hardware that i won't need.


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## Scooter M (Apr 16, 2014)

Hugues said:


> Roman at Emrax told me recently he was expecting to finish the tests on his new 348 this autumn.
> 
> I'm planning to use 72 Leaf modules, paired by 2. Charged at 4.1 volts per cell, that's 295 volts out of the charger. Roman told me to use the low voltage Emrax and use 2 controllers to get the full power out of the motor.
> 
> ...


Here is where I have some concerns.

1.) 1,000+ amps required at 295v to make 300kw. Is both the motor and controller up to the task of handling such amperages, even only for a few seconds? You also need to look at cont. and peak rating are on the Leaf cells. Will they meet the peak and cont. requirements?

2.) By all appearances, the EMRAX 348 seems to be built for a high torque, direct drive application. Will the G50 transmission handle up to 1000nm of torque?

Please reply.


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## minispeed (Jun 30, 2013)

This motor sounds like super overkill for running a stock gear box. 

1000 NM is about 700ftlb. A very quick search and some people on a gt40 forum were saying that the G50 can handle 380ftlb and from the factory five forum that 5 speed boxes actually had a stronger pinion and ring gear than the 6 speeds. Although I'm pretty sure that there have been race porsches putting down 700 ftlbs somewhere in the world it is a far cry from what even the meanest road car was meant to handle.

I doubt even 3rd or 4th would be able to put decent power down with that much. Since a tranny is pretty much a torque multiplier you'd probably get the same real world performance with a lower spec motor that lets you use the lower gears and might even get better performance if it gives you a higher max rpm.


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## Scooter M (Apr 16, 2014)

minispeed said:


> This motor sounds like super overkill for running a stock gear box.
> 
> 1000 NM is about 700ftlb. A very quick search and some people on a gt40 forum were saying that the G50 can handle 380ftlb and from the factory five forum that 5 speed boxes actually had a stronger pinion and ring gear than the 6 speeds. Although I'm pretty sure that there have been race porsches putting down 700 ftlbs somewhere in the world it is a far cry from what even the meanest road car was meant to handle.
> 
> I doubt even 3rd or 4th would be able to put decent power down with that much. Since a tranny is pretty much a torque multiplier you'd probably get the same real world performance with a lower spec motor that lets you use the lower gears and might even get better performance if it gives you a higher max rpm.


Thanks for making my point. If he is really serious about a 3 second car, there are 400hp single powertrain solutions for EV's, but not cheap. I think either give up the 3 second goal or maybe even think about a dual powertrain AWD type solution.


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## Hugues (Jul 13, 2014)

Scooter M said:


> Here is where I have some concerns.
> 
> 1.) 1,000+ amps required at 295v to make 300kw. Is both the motor and controller up to the task of handling such amperages, even only for a few seconds? You also need to look at cont. and peak rating are on the Leaf cells. Will they meet the peak and cont. requirements?
> 
> ...


thanks for your feed-back,

re: 1) quote from Emrax designer about his 348 and following my questions:
_"If you decided for 200Vdc you should take EMRAX 348 Low voltage type if you want to rotate it on higher speed.
Because of very high motor current motor should be made with 2x UVW connectors. In this case you can use two controllers which can fit one motor. In this case the motor can deliver full power"_

The Emrax 348 specs can be found here:
http://www.enstroj.si/News/emrax-348-prototype.html

"Maximal motor current (for 2 min if cooled as described in Manual) [Arms] " = 1200 amps . Continuous = 600 amps.

As for the Leaf (which i use in my current build here) , according to this link, a single module can handle 540 a peak. I'm connecting 2 modules in parallel, so that's 1'080 peak. From what I've seen on my bike in the past 2 years, that does not seem to be impossible.

re: 2) Good point. Somewhere along this thread i mentioned I now changed for a Porsche GT2 transmission. It's the G96/88 with LSD. That's what Hammink performance recommended to me after i mentioned my motor input at 1'000 N-m. There is also a different clutch to handle this torque.

I'm still looking for the official spec of the Porsche G96/88. There are a few forum discussions about it, but haven't seen the official number.


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## Hugues (Jul 13, 2014)

minispeed said:


> This motor sounds like super overkill for running a stock gear box.
> 
> 1000 NM is about 700ftlb. A very quick search and some people on a gt40 forum were saying that the G50 can handle 380ftlb and from the factory five forum that 5 speed boxes actually had a stronger pinion and ring gear than the 6 speeds. Although I'm pretty sure that there have been race porsches putting down 700 ftlbs somewhere in the world it is a far cry from what even the meanest road car was meant to handle.
> 
> I doubt even 3rd or 4th would be able to put decent power down with that much. Since a tranny is pretty much a torque multiplier you'd probably get the same real world performance with a lower spec motor that lets you use the lower gears and might even get better performance if it gives you a higher max rpm.


thanks for your feed-back. Please see my other post just above about the same questions. I now changed for a GT2 transmission. It's the G96/88 There are many different transmissions for the Porsche.

YOu say i'd probably "_get the same real world performance with a lower spec motor that lets you use the lower gears and might even get better performance if it gives you a higher max rpm._"

Any proposal ? I'm for sure completely opened at this stage of my project.


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## Hugues (Jul 13, 2014)

Scooter M said:


> Thanks for making my point. If he is really serious about a 3 second car, there are 400hp single powertrain solutions for EV's, but not cheap. I think either give up the 3 second goal or maybe even think about a dual powertrain AWD type solution.


Thanks for your feed-back Scooter M,

i'm opened to suggestions, do you have something more specific in mind ?

As for AWD, there is just not enough space in front of a GTM to add anything i'm afraid.


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## Kevin Sharpe (Jul 4, 2011)

Hugues said:


> weight of 72 LEAF Gen2	266.4	kgs


One of my 24 module "Gen 2" packs weighs 100kg when all the bus bars, plastic isolation, BMS wiring, and Leaf mounting hardware is used. You'll save weight by using less steel and removing the Leaf module case but be careful you don't underestimate the weight of crash resistant hardware


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## Hugues (Jul 13, 2014)

Kevin Sharpe said:


> One of my 48 module "Gen 2" packs weighs 100kg when all the bus bars, plastic isolation, BMS wiring, and Leaf mounting hardware is used. You'll save weight by using less steel and removing the Leaf module case but be careful you don't underestimate the weight of crash resistant hardware


Thanks for the idea.

I probably won't go this way because:
- i like/need to stack the cells vertically in 4 stacks of 18. Then i need the inner steel tubes to support the weight. 
- i actually need weight at the back to handle such torque on the wheels.


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## Scooter M (Apr 16, 2014)

Hugues said:


> Thanks for your feed-back Scooter M,
> 
> i'm opened to suggestions, do you have something more specific in mind ?
> 
> As for AWD, there is just not enough space in front of a GTM to add anything i'm afraid.


Sounds like Emrax intends to make you a custom motor with dual windings to let you use two controllers. Did they happen to quote you how much this custom motor and controllers would be?

I'm confused by their spec sheet. It reads the battery voltage range is "10-130 (300*). The 300V option is only for a few seconds? Then how do you manage continuous operation? Is the literature suggesting one switches from 300V to 130V? Confusing. One can only operate with a single pack voltage. Not sure what they mean.

Typically high performance EV motors run at high RPMs so the motor is not taking the full load from rev 1. The motor has to be able to build the power to shoot you off the line. You still want a 3 second car, right?

I will be honest with you. I think your trying to make the Emrax motor work with your performance requirements and I don't see it happening.

I am sticking with my first choice in motor and controller.

You need one of these:
http://www.evwest.com/catalog/produ...ucts_id=300&osCsid=mqmsvo3pt7s19jreokjm2104f6

And two of these:
http://www.evwest.com/catalog/produ...ucts_id=262&osCsid=mqmsvo3pt7s19jreokjm2104f6

Email the folks at EVWest at [email protected] to get their opinion. They were very helpful with my speed boat build. Here are links:
http://www.evalbum.com/5217
https://www.youtube.com/watch?v=my0TX3INjSk
https://www.youtube.com/watch?v=BRqcp4Tzzrg

Your pack voltage would need to be 360V. Choose PM150DX - 450Arms continuous, 160 - 360VDC, option for the controller.

By the way, if you did the work on that custom bike, you are one hell of a talented fabricator.

I wish you all the best.


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## Duncan (Dec 8, 2008)

I just looked at the prices - ouch!!

My suggestion would be to not go down that route!

Get hold of a Tesla rear motor/reduction gear/invertor unit and see if you can fit it into the rear
If necessary simply cut the rear of that chassis off and make a new one around the Tesla bits
Then use one of the universal brain boards that are being developed for the invertor 

This will give a lot more space for your batteries (and keep them really low!)
and save a lot of money

This would be playing to the strengths of the the electric transmission rather than using a design that has been compromised by the requirements of the IC engine


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## Scooter M (Apr 16, 2014)

Duncan said:


> I just looked at the prices - ouch!!
> 
> My suggestion would be to not go down that route!
> 
> ...


I was not aware of someone cracking Tesla's controller to reprogram for use on a custom EV build. Who has worked that out and where can it be purchased. Are you just talking about using a Tesla motor and gear box from a salvage lot? I know Jack Rickard of EVTV.me was working on that a year ago. I don't know if he figured it out or not. I noticed he is not selling the Tesla drive train on his site.


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## Duncan (Dec 8, 2008)

Hi Scooter
This is the thread I was thinking about
http://www.diyelectriccar.com/forums/showthread.php/any-ac-motor-any-inverter-umc-152234.html
On page 3 he gets hold of a Tesla drive train


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## Scooter M (Apr 16, 2014)

Duncan said:


> Hi Scooter
> This is the thread I was thinking about
> http://www.diyelectriccar.com/forums/showthread.php/any-ac-motor-any-inverter-umc-152234.html
> On page 3 he gets hold of a Tesla drive train


As far as I can tell, both he and Jack Rickard have managed to get the Tesla motor to spin. Beyond that, I can find no example of a build using such, nor can I find a place to order either the "UMC Drive" or any other complete Tesla drive train solution for use in custom EV builds. Could you direct me to what, who or where someone can get information on pricing and how to purchase? With the exception of the Tesla power train being a bit heavy, the 382hp version would be perfect. Please reply.


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## Duncan (Dec 8, 2008)

Hi Scooter
I'm not an electronic guy - and I don't have that sort of money!
I would suggest that you PM the people who are working on this and see if any of them are interested in helping you - and helping themselves

I have a beta version of the Paul & Sabrina DC controller - Paul was very helpful and also interested in having somebody else to share a (small) part of the costs and do some testing

Maybe eldis would like the same?

The Tesla motor/invertor unit seems to be relatively cheap just now for exactly that reason


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## Hugues (Jul 13, 2014)

Guys,

thanks for your input on the Tesla drive train. I will contact Eldis, he lives 1 hour away from me. But for now the Tesla drive seems to be a long shot for my first car build. I have the long term goal of commercialising this EV car so i need to be sure i can find the main components of the shelf.


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## Hugues (Jul 13, 2014)

Scooter M said:


> ...
> 
> By the way, if you did the work on that custom bike, you are one hell of a talented fabricator.
> 
> ...


Thanks

I designed it and built the electric system myself. The body work and paint job was done by some friends of mine, i don't have the patience for this kind of work.

Hugues
www.zvexx.com


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## Kevin Sharpe (Jul 4, 2011)

Scooter M said:


> I know Jack Rickard of EVTV.me was working on that a year ago. I don't know if he figured it out or not.


They are close...

https://youtu.be/f4mzmRzUNJ0


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## minispeed (Jun 30, 2013)

Hugues said:


> thanks for your feed-back. Please see my other post just above about the same questions. I now changed for a GT2 transmission. It's the G96/88 There are many different transmissions for the Porsche.
> 
> YOu say i'd probably "_get the same real world performance with a lower spec motor that lets you use the lower gears and might even get better performance if it gives you a higher max rpm._"
> 
> Any proposal ? I'm for sure completely opened at this stage of my project.


 
I don't know much about the different motors out there to say one for sure. I can only give my advice and of coarse respect that it's up to you to figure out. You sound really open to taking advice online which is a nice change of pace. 

I'd go with what's known to work, a DC high power motor on a Porsche transaxle will work well. Build that first running on 12v then stuff as many batteries that fit and see what you get. If you're not happy with it we are only a few years away from used packs with double the kWh being available, enjoy the car then bring it in for an update. 

From my perspective you're spending a ton of money and adding complexity to get that last little bit of performance and the trade off in reliability or even if it will work exactly as planned isn't worth it.

Since you can always upgrade once the car is driving and you have performance data it will probably be cheaper in the long run to go through 2 versions as battery options change than shoot for the stars right now. Plus the second version will either be a big bump in range or a big drop in weight. I'm a big fan of less weight. If you couldn't tell from what I've written I'm a big lotus fan LOL.


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## tylerwatts (Feb 9, 2012)

Hi Hugues

I would recommend running 2 Emrax 248 motors locked together with a custom dual controller or 2 off the shelf linked controllers. Higher rpm in a lower gear will give you better mechanical advantage and help your traction off the line. You could also avoid having multiple gears. Single sped is the best bet in my view.

I look forward to your progress.

Cheers


Tyler


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## Hugues (Jul 13, 2014)

tylerwatts said:


> Hi Hugues
> 
> I would recommend running 2 Emrax 248 motors locked together with a custom dual controller or 2 off the shelf linked controllers. Higher rpm in a lower gear will give you better mechanical advantage and help your traction off the line. You could also avoid having multiple gears. Single sped is the best bet in my view.
> 
> ...


thanks for your feed-back,

i'm struggling with the space available, at present 2 Emrax 248 won't fit. I can barely fit one. I don't want to sacrifice battery pack at this point.

I received the dimensions of the Porsche GT2 G96/88 transaxle, crap, it's longer than the G50, so i don't have enough space for the motor cables and water intake. I need to find a more compact transaxle.

Recap so far:
- 72 Leaf modules in 4 stacks of 18, paired 2 by 2, for 274 volts nominal (max 295 volts off the charger)
- I can pull 1'080 amps peak from the battery pack, 480 amps continuous
- Motor is Emrax 348, that's the smallest i found with the power and torque i need to maximize 0-60 acceleration, target is low 3.0 sec.
- I asked Roman at Emrax to propose me the controllers to work with his motor.
- So i'm looking for a compact transaxle/differential that can handle 1'000 N-m

I contacted Quaife in the UK, still hoping their compact transaxle can handle this.

Any suggestion on compact transaxle are welcomed. I know the Tesla drivetrain could work out pretty well, but i'm not sure if i can find one. So would like to see other options.


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## Kevin Sharpe (Jul 4, 2011)

Hugues said:


> So would like to see other options.


My Tesla Roadster Sport weighs 1,300 kg and does 0-60 mph in 3.7 seconds. It uses the Borg Warner eGearDrive that's available from evtv;

http://store.evtv.me/proddetail.php?prod=eGearDrive

The eGearDrive has a simple splined motor shaft and eTransit/CODA drive shafts are readily available. It might make a simple and low weight solution (28 kg) when combined with one or two motors in series...


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## Hugues (Jul 13, 2014)

Kevin Sharpe said:


> My Tesla Roadster Sport weighs 1,300 kg and does 0-60 mph in 3.7 seconds. It uses the Borg Warner eGearDrive that's available from evtv;
> 
> http://store.evtv.me/proddetail.php?prod=eGearDrive
> 
> The eGearDrive has a simple splined motor shaft and eTransit/CODA drive shafts are readily available. It might make a simple and low weight solution (28 kg) when combined with one or two motors in series...


Hi Kevin,

Ok, let's put my Emrax 348 motor aside for now and design around the Borg Warner eGearDrive. It can handle max 300 N-m input torque peak. So let's use that in the EVdesigner spreadsheet to check what's the fastest acceleration i can get.

I attach the spreadsheet. I used the highest gear ration available, 9.07, reduced my total weight to 1183 kgs because the Borg is lighter than the Porsche transaxle. The best acceleration i can get is 4.2 sec. Not sufficient, i want less than 4, and low 3.0 ideally.

Unless my numbers are wrong, the Borg eGeardrive will not work. I need a transaxle that can handle at least 400 N-m to get me down to 3.4 sec. And a compact one.


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## Kevin Sharpe (Jul 4, 2011)

Hugues said:


> Unless my numbers are wrong, the Borg eGeardrive will not work.


I've verified the Tesla Roadster 0-60 on a drag strip (we achieved 3.8 seconds) and believe the published weights are correct (1,300 kg including one 70 kg driver). Given the Roadster is using the eGearDrive (owners manual says overall final drive ratio is 8.27:1) I can only assume something is wrong with the spreadsheet you are using 

FYI the Roadster owners manual also says the motor maximum net power is 185 kW (248 HP) @ 5500-6800 rpm, and the maximum net torque is 376 Nm (277 lbf.ft) @ 0-4500 rpm. 

A few years ago I looked seriously at trying to beat the Roadster numbers with a GTM based solution... I could not build anything that could match it for the price... maybe that's why the Rimac Concept One, which comes close to your requirements, costs $1,000,000 

If I was doing a GTM today then i'd look seriously at the Tesla/Quaife solution from EVTV because Jack has the cash to deliver a working solution... I believe Jack's first customer is putting this into a 'race car' so we should know how it performs at some point. Lots more info is available on this EVTV video (start at 36m28s);

https://youtu.be/f4mzmRzUNJ0?t=36m28s

Alternatively, I'd just buy a Model S and use it in ludicrous mode (0-60 in 2.5) because that will probably be cheaper and I could have it in a couple of weeks


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## Hugues (Jul 13, 2014)

Kevin Sharpe said:


> I've verified the Tesla Roadster 0-60 on a drag strip (we achieved 3.8 seconds) and believe the published weights are correct (1,300 kg including one 70 kg driver). Given the Roadster is using the eGearDrive (owners manual says overall final drive ratio is 8.27:1) I can only assume something is wrong with the spreadsheet you are using
> 
> FYI the Roadster owners manual also says the motor maximum net power is 185 kW (248 HP) @ 5500-6800 rpm, and the maximum net torque is 376 Nm (277 lbf.ft) @ 0-4500 rpm.
> 
> ...


I plugged in 376 N-m in the EVdesigner spreadsheet and 1300 kg, with 17 inc rim, i do get 3.8 sec, but i had to up the peak power to 230 kw. But anyway we're close and i certainly believe your 3.8 sec.

I will contact Borg Warner to understand if their eGeardrive can hold more than 300 N-m, maybe they had a special version made for the roadster. But anyone knows where i can get the dimensions of their drive ? Ideally a 3d cad file.

I'm also in contact with Ben from Quaife, seems they have a few transaxle that can match what i need. He also told me about their differential for the Tesla. Guess i should drop a mail to EVTV.

Thanks for your input, much appreciated


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## Duncan (Dec 8, 2008)

Just a wee thought about your gearbox worries

The manufacturers ALWAYS go conservative with the ratings most things will take a 50% overload

You are building a light car - the manufacturers would be making allowances for somebody putting the gearbox into a much heavier vehicle - which could load it for longer

In an IC car the gearbox has got to cope with the instantaneous "clutch drop" torque 
this can be a LOT more than the actual operating torque

For a major manufacturer a failure rate of 50/million would be considered high 
For a small scale manufacturer (or one off) a failure rate of 1/100 would be OK

You can get away with running a much higher loading


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## John Metric (Feb 26, 2009)

For the next version of my fiero, I was thinking of putting two motors on my dual motor overdrive and wrap the system back under itself to a differential. It would be a rear engine car dual motors, overdrived for correcting rpm peak power to 6000rpm like a big V8. It would look cool as well.
Here is one impulse9 motors mounted in the arrangement I am thinking. The second motor removed for maintenance. You can see the differential would be in the correct location, you would have 1500ftlbs of torque before the overdrive and 750ftlbs afterwards, like a big V8. a three speed is shown with reverser.


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## Hugues (Jul 13, 2014)

John Metric said:


> For the next version of my fiero, I was thinking of putting two motors on my dual motor overdrive and wrap the system back under itself to a differential. It would be a rear engine car dual motors, overdrived for correcting rpm peak power to 6000rpm like a big V8. It would look cool as well.
> Here is one impulse9 motors mounted in the arrangement I am thinking. The second motor removed for maintenance. You can see the differential would be in the correct location, you would have 1500ftlbs of torque before the overdrive and 750ftlbs afterwards, like a big V8. a three speed is shown with reverser.
> ...


That's interesting. You had that custom made i suppose ?

How are the motors linked to the input of the differential ? gears ? chains ? belts ? Have you got a schematic or a picture of the inside ?


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## John Metric (Feb 26, 2009)

Hugues said:


> That's interesting. You had that custom made i suppose ?
> 
> How are the motors linked to the input of the differential ? gears ? chains ? belts ? Have you got a schematic or a picture of the inside ?


Yes I have two right now. They are available for purchase. $4000 NEW.
It does a bunch of functions, it drops the motor shaft 11", it combines two or four or more motors into one output shaft in a side by side arrangement when two end to end is too long, or four is out of the question any other way.
Inside it is all gear driven, it overdrives the output by 2:1, correcting low rpm dc motors by a factor of two. Giving peak HP Warp motors (at 3000rpm 2kA) a more proper rpm of peak HP at 6000rpm, making gear selection more appropriate. The output from the overdrive is currently a 32 spline shaft but could be anything, it is pilot bearing'd for a Lenco transmission, shown above, then a Lenco reverser at the end of the lenco reverser in the car show it is just direct coupled to the differential (the piece in between the tires), but could be a short couple drive shaft for suspension play if any by as short as a 6" drive 1350 drive shaft as seen on DC Plasma.

I would be happy to talk with you about it. my num is 979 665 5621 ym email is john dot metric at yahoo dot com


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## Hugues (Jul 13, 2014)

John Metric said:


> Yes I have two right now. They are available for purchase. $4000 NEW.
> It does a bunch of functions, it drops the motor shaft 11", it combines two or four or more motors into one output shaft in a side by side arrangement when two end to end is too long, or four is out of the question any other way.
> ...


Well, just checked my 3d model, there is really not much space on top of the transmission either. The FFR GTM is a really low profile car, i think 1m08 on top of the roof, and about 2/3 of this at the back.

I need to think more.

But thanks for the offer,.


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## eldis (Sep 3, 2013)

Hi Hugues,

Thanks for your email! I see u have quite interesting projects going on.

I saw my name popping out a few times here. There is a fair bit of information noise around, I'll try to update my threads about Tesla and the UMC a bit with the latest information to keep u guys posted.


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## BHammy (Sep 15, 2016)

Hugues said:


> - So i'm looking for a compact transaxle/differential that can handle 1'000 N-m
> 
> Any suggestion on compact transaxle are welcomed. So would like to see other options.


The Albins ST6-M just may be your huckleberry:

http://www.albinsgear.com.au/assets/Documents/ST6Binder.pdf

It's the transaxle used in the Australian V8 Supercars.


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## John Metric (Feb 26, 2009)

Hugues said:


> Well, just checked my 3d model, there is really not much space on top of the transmission either. The FFR GTM is a really low profile car, i think 1m08 on top of the roof, and about 2/3 of this at the back.
> 
> I need to think more.
> 
> But thanks for the offer,.


Could you estimate if this motor would fit?









It is 15.4" from pinion drive shaft to opposite end.
I would say you could direct drive a Ford 8.8 IRS rear end.
This motor has potentially 1350ftlbs torque from 0 to 8000rpm if you have the battery to handle that.
Top speed of 10,000rpm.

You could skip the porsche transaxle weight and cost.

Here is one installed in my dragster. Obviously you probably wouldn't need to have an underdrive and reverser so it could go directly to the differential pinion.


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## AdamV (Jun 2, 2017)

minispeed said:


> hybridautocentre.com sells packs that come from wrecked cars so for that it's a bit of a waiting game...
> 
> I'm sure they'll provide packs as they become available.
> 
> ...


Why go with used batteries from production cars versus new lithium batteries? 
Isn't it a pain to work around their wiring and cooling systems?


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## AdamV (Jun 2, 2017)

I apologize for jumping in the middle of this but Ive been trying to find some answers about a similar situation for quite some time.

Can I ramble a bit about an electric sand rail I'm building and the drive line I'm hoping to find?

Adam


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## Duncan (Dec 8, 2008)

Hi Adam
You would be better off starting your own thread

_Why go with used batteries from production cars versus new lithium batteries? 
Isn't it a pain to work around their wiring and cooling systems?
_

Used batteries are a fraction of the price and an order of magnitude higher quality!

As far as the cooling/wiring - ignore or use - it's your choice


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## AdamToth (Jun 17, 2018)

Hi Hugues

You've been writing about your project for a long time. I really like the project. I've already looked at the GTM ... it would be good to make it electric, but I'm not sure I'm fit . We are dealing with high performance 3 phase motor controller development. We have not tested a double controller on one emrax, but if it has not been resolved then we would be happy to cooperate.

Adam Toth
https://www.drivetraininnovation.com/


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