# RX-7 Build



## elevatorguy (Jul 26, 2007)

I recently started gathering parts for a Mazda rx7 build and want to make it fun to drive. I have the car, manual trans, warp 9, vacuum pump and misc.
I am choosing a controller and batteries and would like some input to what worked well for others.
I am looking at 1k zilla and solitron1, both look like solid controllers but would like to know real world use input, likes/dislikes. 
System voltage will be 144 or 156v and trying to figure battery options, 100ah, 130ah or 160, I want to put fun factor in but not break the bank in the process.
The car will be lightened as much as possible, it is about 2000lbs now w/o engine and driveline.
This is not needed to commute, but would like 50 or so mile range.


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## kerrymann (Feb 17, 2011)

elevatorguy said:


> I recently started gathering parts for a Mazda rx7 build and want to make it fun to drive. I have the car, manual trans, warp 9, vacuum pump and misc.
> I am choosing a controller and batteries and would like some input to what worked well for others.
> I am looking at 1k zilla and solitron1, both look like solid controllers but would like to know real world use input, likes/dislikes.
> System voltage will be 144 or 156v and trying to figure battery options, 100ah, 130ah or 160, I want to put fun factor in but not break the bank in the process.
> ...


I have no experience with the zillas but I highly recommend the soliton1. I used it in my miata build and it definitely makes the car fun. It is plenty powerful and very programmable.


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## Snakub (Sep 8, 2008)

As I have installed a soliton 1 for someone I recommend the zilla it simply has more programmability like if you ever wanted to go dual motor the zilla has an automatic shift between series and parallel overspeed limiting and it actually has an interface option I think its just the better choice in the long run.


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## elevatorguy (Jul 26, 2007)

Thanks for the input, I went a different direction and picked up a netgain controls 600V 1200Amp. I hope I will be happy with it, it does limit me to 160V or adding motors but I probably won't have the need.
I got the gas tank out and freed up a nice battery space and lost another 50 lbs off the car.
Looks like 100 AH batteries are out, I think they won't meet the current demands and I don't want to be limited by the batteries.


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## dougingraham (Jul 26, 2011)

elevatorguy said:


> I recently started gathering parts for a Mazda rx7 build and want to make it fun to drive. I have the car, manual trans, warp 9, vacuum pump and misc.
> I am choosing a controller and batteries and would like some input to what worked well for others.
> I am looking at 1k zilla and solitron1, both look like solid controllers but would like to know real world use input, likes/dislikes.
> System voltage will be 144 or 156v and trying to figure battery options, 100ah, 130ah or 160, I want to put fun factor in but not break the bank in the process.
> ...


I am using 51 100AH cells in my 85 RX-7 with a WarP9 and a Soliton 1. Way faster and more fun than the original car. Only added a little overall weight. It is about 600 lbs on each wheel. I have 33 cells in the back where the gas tank and spare tire were and 18 cells in a battery box under the hood. I would have put in a few more cells but there just isn't room without making it difficult to maintain.

If I were doing it today I would use as many of the 60AH CALB CA cells as I could fit up to the limit of the controller (98 cells) and possibly use a Soliton Jr to make room for a few more cells under the hood. It would still be faster than original with a Jr and the higher voltage would increase the usable torque band.

At 1000A I have more than 2.5 times the torque of the original 12A rotary from 0 to about 3500 rpm. If you press the throttle to the floor in second it throws you back in the seat and some exclamation will come out of your mouth like "Mother of God!" This gets you to 25mph in well under a second. I have the slew rate turned down so I dont just spin the tires. First gear is pretty useless as you cant even get to 1000 amps and you have to shift too soon. I often just leave it in third when driving around town and shift into 5th when on the highway.

You don't say what model of Rx-7, mine is an FB or first generation which was the lightest of the three generations. But I think any of them would make a great EV.

Best Wishes!


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## elevatorguy (Jul 26, 2007)

That sounds like what I want, some kind of exclamation or frightened passenger.
I thought about the 100 AH batteries but figured the sag due to loading would be too hard on them. I am kind of locked in on the voltage at 160v unless I upgrade the controller.
The car is an 1986 second generation with a aluminum hood from a turbo car all extra weight removed. Trans will be from a 89 turbo car.
If you aren't roasting tires or snapping necks, what kind of range do you get out of the 85?
Any problem breaking transmissions or rear ends?


dougingraham said:


> I am using 51 100AH cells in my 85 RX-7 with a WarP9 and a Soliton 1. Way faster and more fun than the original car. Only added a little overall weight. It is about 600 lbs on each wheel. I have 33 cells in the back where the gas tank and spare tire were and 18 cells in a battery box under the hood. I would have put in a few more cells but there just isn't room without making it difficult to maintain.
> 
> If I were doing it today I would use as many of the 60AH CALB CA cells as I could fit up to the limit of the controller (98 cells) and possibly use a Soliton Jr to make room for a few more cells under the hood. It would still be faster than original with a Jr and the higher voltage would increase the usable torque band.
> 
> ...


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## dougingraham (Jul 26, 2011)

elevatorguy said:


> That sounds like what I want, some kind of exclamation or frightened passenger.
> I thought about the 100 AH batteries but figured the sag due to loading would be too hard on them. I am kind of locked in on the voltage at 160v unless I upgrade the controller.
> The car is an 1986 second generation with a aluminum hood from a turbo car all extra weight removed. Trans will be from a 89 turbo car.
> If you aren't roasting tires or snapping necks, what kind of range do you get out of the 85?
> Any problem breaking transmissions or rear ends?


At the moment about 60 miles but I think I have a wheel bearing going out and the brake pads are dragging a little bit. I expected over 80 miles. I will know more once I get my other issues ironed out. I will probably just repack all the bearings and change out the one that is grumbling.

I have not had any issues with breaking transmissions or rear ends. I dont think I could break either because the clutch is just the regular clutch and the tires are the stock size 185/70 R13's so not enough traction. But I haven't ever wound it up and dropped the clutch either. No point as this is just asking for trouble and you can take off faster not spinning the tires.

The final drive ratio is not really right for an EV. That is the biggest issue if you are looking for performance. Something closer to 3.4 or 3.5:1 instead of the 3.9 or 4.1 used in most of the Rx-7's. Not sure what that difference in the 89 turbo transmission is.


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## elevatorguy (Jul 26, 2007)

The turbo trans is a little stronger but using it because my parts car is an 89
I bought the 86 no trans or engine. 
I figured the range would be 50-70 with the 100 AH batteries.
Your build is very close to what I am aiming for, I am not sure I will get better traction with the 205/60/15 tire setup, perhaps a taller tire to get a better ratio


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## dougingraham (Jul 26, 2011)

elevatorguy said:


> I figured the range would be 50-70 with the 100 AH batteries.
> Your build is very close to what I am aiming for, I am not sure I will get better traction with the 205/60/15 tire setup, perhaps a taller tire to get a better ratio


Narrow tires tend to have less air drag and can have lower rolling resistance. It all depends on your goals. I have plenty of range for my daily mission so a little extra performance was part of the mix. If you really need all your range then more emphasis will need to be placed on that and wide tires might hurt the range. I am not sure a tire that was an inch or two larger diameter will be noticeable.


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## PowerSurge (Jan 24, 2013)

I'll be interested in seeing your build, as I'm doing an 88 RX7.


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## elevatorguy (Jul 26, 2007)

I will be hitting it hard soon, I removed the engine and trans from the parts car, that turned out to be an 87 not 89 as I thought.
I have a call in to get adapter made and just confirmed battery purchase.
Still haven't gotten the controller in yet 
Still need to find a charger and dc/dc and a few other parts.




PowerSurge said:


> I'll be interested in seeing your build, as I'm doing an 88 RX7.


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## PowerSurge (Jan 24, 2013)

elevatorguy said:


> I will be hitting it hard soon, I removed the engine and trans from the parts car, that turned out to be an 87 not 89 as I thought.
> I have a call in to get adapter made and just confirmed battery purchase.
> Still haven't gotten the controller in yet
> Still need to find a charger and dc/dc and a few other parts.


I did some research on the adapter for the RX7, and Canadian EV seems to have the nicest one out there.


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## elevatorguy (Jul 26, 2007)

I will look into Canadian, I was thinking of using the one from electriccarparts because they use a taperlock on the coupler.


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## elevatorguy (Jul 26, 2007)

PowerSurge said:


> I did some research on the adapter for the RX7, and Canadian EV seems to have the nicest one out there.


I went with the Canadian EV setup, worked well and looks good.
I got the car about more than half done, I am still needing a warp drive interface module to dial the power in and protect my batteries. 
I have worked out the speed sensor but need to figure out how to shut down the controller without errors or startup sequence.
NGC hasn't responded to 3 emails about the interface and shutdown questions.


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## skooler (Mar 26, 2011)

elevatorguy said:


> I went with the Canadian EV setup, worked well and looks good.
> I got the car about more than half done, I am still needing a warp drive interface module to dial the power in and protect my batteries.
> I have worked out the speed sensor but need to figure out how to shut down the controller without errors or startup sequence.
> NGC hasn't responded to 3 emails about the interface and shutdown questions.


Any pics? would be good to see


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## elevatorguy (Jul 26, 2007)

skooler said:


> Any pics? would be good to see


I have some pics in the garage section and on the blog, mhomoney.blogspot.com


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## elevatorguy (Jul 26, 2007)

Frustration abounds, I got the car more or less put together, batteries in and connected, emergency disconnect etc.
I tried to charge a bit, but the charger would not come on line and charge 
So, I try to run the motor on the the pack, so far only ran at 12 volts, nothing!
Error on warp drive, This just came from netgain with the throttle they tested it with and I am getting a throttle error I think, the fault will not clear 
I was supposed to have this ready for a EV club meeting on the 7th, I think this will not happen.
I was finally able to access the charger (DOS Based) to figure out why it won't start and got it to start charging, thankfully as the batteries have been setting since March and I was getting worried about them.


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## elevatorguy (Jul 26, 2007)

Still no response from NGC, I purchased and installed a solitron 1. I got the car on the road a few days ago and am impressed with the power! it is a blast to drive. I have a few mechanical issues with the car to resolve yet but it is on the road. I broke a speedo cable the second time out and got that replaced, all good. installed the meters to keep an eye on things. I am averaging 240-280 wh a mile. I got the car weighed, balance was only 40# difference front to rear.
The car is a little heavier than stock 2790, came in at 2840.
I am very pleased with performance, and glad to be on the road finally


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## dougingraham (Jul 26, 2011)

elevatorguy said:


> I am averaging 240-280 wh a mile. I got the car weighed, balance was only 40# difference front to rear.
> The car is a little heavier than stock 2790, came in at 2840.
> I am very pleased with performance, and glad to be on the road finally


Great! Glad you have it on the road.

Being only 50 lbs over ICE is a good result. Hope you bring it to EVCCON next year. I would love to see it. Your WH/mile is better than I am seeing. I measure mine at the outlet though and it is about 15% better if I measure it at the batteries.


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## elevatorguy (Jul 26, 2007)

dougingraham said:


> Great! Glad you have it on the road.
> 
> Being only 50 lbs over ICE is a good result. Hope you bring it to EVCCON next year. I would love to see it. Your WH/mile is better than I am seeing. I measure mine at the outlet though and it is about 15% better if I measure it at the batteries.


I am getting my amp hours from the AH meter in the car, the information from the charger is confusing, it showed 135 ah into the batteries and they were not fully discharged. 
I was hoping to get it to National Plug in day event near me this weekend, not sure I will get to EVCCON unless it is close.


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