# Tesla Powered Cobra Race Car



## tiger82 (Sep 23, 2015)

I'd like to present our Tesla powered Race Car project. The car utilizes a custom designed chassis, drivetrain from a Tesla P85, body from a classic 427 Cobra, and a battery pack from a Kia Soul EV.

I am a long time road racer (Sunbeam Tiger, Mustang GT1, Toyota MR2) in the PNW and have been wanting to build an electric race car for a while. However, up until now, the cost of doing this has been prohibitive. The availability of OEM EV components in the salvage yard has changed things. 

This car is being collectively built by a group of friends who love the idea of doing something different. We have been working on the project for since December 2015, and are hoping to have the vehicle on track for testing this summer. We call ourselves "EPower Racing"

The motor is from a Model S P85 which is rated at 310 kW peak. However, we have no illusions that we will be able to run the motor at anything close to that for sustained periods due to overheating of the motor/inverter. We are putting in lots of extra cooling but only testing will tell if that helps. All reports we hear of from Tesla Track Days show Model S's going into power limiting within a couple of laps. For longer events, we will probably limit the maximu power to the motor to prevent heat build-up. Although we will have regen capabilities, we will most likely not use it the same reason. (Regen would also upset the brake balance as well which would be undesirable for a race car). 

We realized very early on that the massive available torque and an open differential without the benefit of Tesla's traction control system was not a good combination. We worked closely with Jack Rickard/EVTV and Quaife Engineering to produce a custom torque biasing differential. These are now available from EVTV. 

We chose the Kia Soul EV as the battery pack donor largely based on DOE test reports which showed it as one of the few OEM packs capable of putting out over 300kW for sustained length of time. It is also one of the lightest packs available. The 30 kw-hr pack (27 usable) only weighs 400 pounds. We purchase what was probably the first Kia Soul EV that was written off, and hauled it across North America! It was fully functional vehicle which allowed us to do some reverse engineering of the CAN bus. We are able to utilize the factory charger for both regular and ChaDeMo charging and obtain cell temperature and voltage data from the BMS. We will be limited in the duration of our runs due to the pack size, but we didn't want to double up on the pack before we even had any real world test data.

The chassis was designed in Solidworks including FEA optimization. The chassis with roll cage weigh about 220 pounds. VR3 engineering took our CAD files and CNC cut and bent all the tubes. 

The suspension utilizes C5 Corvette spindles and hubs to keep costs down. However, since we were designing both the frame and A-arms, we were able to dial in exactly the geometry we needed using our SusProg3D suspension analysis program.

Total design weight of the vehicle with driver is 1800 pounds which, even with a torque limited motor, should give us a very good power to weight ratio.

The goal is to have the vehicle on the dyno early spring, then on track for testing in the summer.



https://www.youtube.com/watch?v=Ci8kHAb6iVw


----------



## Yabert (Feb 7, 2010)

Oh!! This toy will be insane 
Nice!


----------



## itchyback (May 28, 2014)

Thats hot, i think i made a mess.


----------



## Rory166 (Jul 6, 2014)

Fabulous build. IMHO you must use regen breaking to the max possible. Without your laps will be severely limited, I would expect this to give you perhaps 50% more laps. Depending on the track type, much less on a high speed oval. I do not see the brake balance being such an issue as it is in highbrid formula 1 cars as they fully charge their batteries I think. 4 wheeldrive would be a big benefit as it would give front wheel regen breaking.


----------



## tiger82 (Sep 23, 2015)

Our Tesla Cobra EV finally hit the race track in June and we have now run 3 races and a number of test sessions with it.

The performance has met our expectations and has surprised a lot of people!

As predicted, range, length of time to recharge, and battery/motor temperatures have been the issues. However, we did complete one 20 minute race at 180kW peak power setting and a second at 220kW. We have run the motor up to 300kW on the dyno, but it is unlikely we will ever be able to run at that level in a race. Qualifying sessions and time trials are a different story though!

Here's a link to some in-car footage:
https://www.youtube.com/watch?v=onPaceYswN4

Regenerative braking will help our range issues, but doesn't help with the temperature issues. It's a fine balancing act! We have tried running with various levels of regenerative braking but it makes the car hard to control at turn-in. In the one race we ran with regen on, I compensated by putting on some throttle at turn-in to disengage the regen braking. 
(Tesla uses a throttle off/regen on strategy). In the future, we will try to implement a strategy to only use regen during straight line braking.


----------



## RIPPERTON (Jan 26, 2010)

tiger82 said:


> The performance has met our expectations and has surprised a lot of people!


In reality you pissed them off.
ICEers hate being beat by electric cars.
Off the track, be very diplomatic, tread lightly and dont brag.
On track you will still be embarrassing them and they will eventually eek you out.
At least thats what happened down here (ELMOFO electric Radical)
Personalities might be different up there.

How many laps would you get on full power ? I think it would be at least twice as much as a Model S because of the weight.


----------



## dedlast (Aug 17, 2013)

Nice! That thing's got some legs.

B


----------



## tiger82 (Sep 23, 2015)

I think having a lighter car only helps with range if you run at the same power levels. Our pack is 27 kW-hrs. We are using all of that in 20 minutes - which is about 16 laps on a 1.4 mile road race course.


----------



## foxr (Apr 16, 2015)

I'm very interested in doing this to a vehicle myself for daily driving not racing. What controller is being used to run this thing? What is required from the tesla besides the rear drive unit which I see on ebay for $10k?


----------



## tiger82 (Sep 23, 2015)

We're using the controller from EV Controls: http://www.ev-controls.com/

They've done a fabulous job for us. Chris has been running his Tesla powered Factory Five 818 for over a year now, so has more experience in this area than anyone else I know.


----------



## OPSash (Oct 13, 2016)

Awesome congrats!


----------



## tiger82 (Sep 23, 2015)

*Lessons Learned and Upgrades for 2018*

We were extremely pleased with the 2017 debut of our Tesla Cobra EV car. It was quick right out of the box despite having to run at lower power levels. The issues we had were problems we anticipated: High motor temperatures, and insufficient battery pack capacity.

* Battery Pack*. The 27kWhr Kia Soul EV pack worked superbly, but was a little small. In order to run our 20 minute races, we had to drop our maximum power to 200kW or lower. Battery temperatures were high, but manageable. We added two high head centrifugal fans to our custom enclosure to help reduce the time required to cool the batteries between sessions. We are attempting to get hold of a 2018 Nissan Leaf 40kWhr pack for the new season. The pack is about the right size, the modules are easy to work with and can be re-arranged to fit into our available space, and the weight should not be much more than our Kia Soul pack (400 lbs). The cars will not be available for sale until Feb. 2018, but we have no doubt that we will be able to find a salvage vehicle within a month or two of release! If anybody can help with locating a pack, it would be much appreciated.

*Motor Cooling*. Stator temperatures would reach 150 degC in about 6-8 laps. To protect itself, the Tesla controller would cut back on the maximum power delivered. At the end of most races, we were down to about 150kW. The Tesla stator/rotor/power electronics are water cooled. Despite having a very high capacity cooling system and an ice reservoir, we were not able to keep the stator temperatures down. (There were no problems with inverter temperatures). This year, we will be experimenting with oil bath cooling of the stator/rotor air gap in addition to the water cooling. We will utilize a water/oil heat exchanger and a positive displacement gear pump to circulate ATF.
*Regenerative Braking*. With 60kW of regenerative braking, we were able to increase our range by 20%. Unfortunately, the car was very difficult to drive due to the huge rear braking bias. The Tesla controller puts regenerative braking on anytime the throttle is off – not good for corner entry. I think I spun the car more times than I have ever spun a car in my life! With a bigger battery pack for 2018 we should be able to get by without regenerative braking.

*Charging*. We utilized the 6.6kW factory Kia Soul charger last race season, but the long charge times (4.5 hours) quickly became an issue limiting us to the number of sessions we could run in a day. For 2018, we will be attempting to piggy-back off the work of the DIY community (Damien Maguire) and utilize two or three Tesla chargers in parallel for 20 or 30kW of charging capacity. We are working with the Sports Car Club of BC at our local track and hopefully will get a 150 amp service installed in the pits for 2018.


----------



## hondarider90 (Jan 14, 2018)

Are you allowed to run AWD? I think running one of the small Tesla units up front would help you with a lot of your issues. You would have more balanced regen, there would also be power splitting, so each motor should get less hot to make the car go the same speed. For racing I wonder if some other non OEM battery solution would get you better results with less weight. The car companies lean the chemistry towards long life, ability to recharge at a fast rate and range. Generally you can get batteries that are lighter and have higher amperage ratings with the sacrifice of battery life, shouldn't be an issue in a car that will probably never see five figures on the odometer before the batteries get upgraded for the latest and greatest.


----------



## tiger82 (Sep 23, 2015)

If we were to build a 2nd generation car we would probably go with two of the smaller Tesla units (or even a pair of Nissan Leaf units) for the reasons you mention. However, this setup would also add a couple of hundred pounds to the car. 

As far as batteries, going the salvage route significantly reduces the cost of the pack. In addition, there are not too many high performance cells actually available to the public. Pretty hard to beat the latest and greatest OEM offerings.


----------



## hondarider90 (Jan 14, 2018)

It would add weight to the car yes, but wouldn't it allow a high enough increase of your current setpoints to offset that? Maybe it would be better on tracks with less turns since the extra weight probably reduces cornering capability.


----------



## hondarider90 (Jan 14, 2018)

Would using C02 cannisters be able to provide the cooling with less weight than the oil bath and ice?


----------



## brian_ (Feb 7, 2017)

tiger82 said:


> *Motor Cooling*.
> Stator temperatures would reach 150 degC in about 6-8 laps.
> ...
> The Tesla stator/rotor/power electronics are water cooled. Despite having a very high capacity cooling system and an ice reservoir, we were not able to keep the stator temperatures down.


That's an interesting challenge.

Do you have coolant temperatures at the inlet and outlet of the motor that you are willing to share?


----------



## tiger82 (Sep 23, 2015)

Yes, if the power we could put to the ground with an AWD setup were high enough, it would overcome any weight disadvantage.

Gaseous cooling is a possibility, but would actually be quite a bit heavier. The flow rates we would require would mean using some very large tanks. We already have the water cooling system which consists of a radiator and high flow electric pump (The ice box use is optional). The addition of the water/oil heat exchanger, gear pump, and lines will add less than 20 pounds.

Water temperatures are very cool. Here's a data point: Stator temp 171 degC, Inverter temp 43 degC, Water in 35 degC, Water Out 37 degC


----------



## brian_ (Feb 7, 2017)

tiger82 said:


> Water temperatures are very cool. Here's a data point: Stator temp 171 degC, Inverter temp 43 degC, Water in 35 degC, Water Out 37 degC


Thanks 

With cooling water gaining only 2 °C in a pass through the motor, the coolant isn't being used very effectively. With the water outlet at 37°C and the stator at 171 °C, the flow of heat through the motor to the coolant is remarkable ineffective. I can see why running coolant through the stator-rotor gap is being considered, since the heat is not flowing effectively from the heat source to the existing coolant path.

If the outlet temperature were high, the solution might be more flow. If the inlet temperature were high, the solution would be a more effective radiator. But those do not appear to be the problems.

I think you're pushing Tesla's motor design into territory for which it was never intended. The cooling is only expected to keep up with average street demands, of perhaps 30 kW motor power; high power is only expected for one stoplight drag race or freeway on-ramp at at time. The heat of high-power bursts is soaked up by motor mass, the way the heat of a single stop is soaked up by brake rotor mass, with the assumption that a much longer cooling period will be available. Higher average power seems to be too much for it.

Leaf motors may have a similar issue, since they are not intended for sustained high power service, either.

I'm looking forward to seeing how this is resolved.


----------



## itchyback (May 28, 2014)

I understand there is a difference between the temperature limit of the motor (being a higher limit) and the inverter (being a lower limit) and for some reason the coolant flows from the motor to the inverter. 
is it possible to reverse the flow so it does the opposite? or separate the two with different cooling systems. 
I also understand the piece at the end of the motor the funnels to coolant into the motor and then to the inverter is one piece so this would need to be redesigned.


----------



## Kevin Sharpe (Jul 4, 2011)

tiger82 said:


> Yes, if the power we could put to the ground with an AWD setup were high enough, it would overcome any weight disadvantage.


Given the 'small' drive units have separate cooling loops for the motor and inverter it's possible you can manage temperatures better than the 'large' DU.

On our conversions we're separating out these two cooling loops and should have some data to report in the next couple of months


----------



## kennybobby (Aug 10, 2012)

tiger82 said:


> ...
> Water temperatures are very cool. Here's a data point: Stator temp 171 degC, Inverter temp 43 degC, Water in 35 degC, Water Out 37 degC


How did you fill the system and bleed out the air? It sounds like you have a vapor lock in the cooling jacket.


----------



## hondarider90 (Jan 14, 2018)

Would water wetter or another advanced coolant take more heat off for racing? The OEM solution isn't always best because it has to work in all conditions.


----------



## Duncan (Dec 8, 2008)

I want to echo KENNY

How did you fill the system and bleed out the air? It sounds like you have a vapor lock in the cooling jacket.

Thinking about it he has GOT to be right - those temperatures cannot be right no engineer would design a system like that

You have an air pocket ! or even worse somebody has lost a rag


----------



## brian_ (Feb 7, 2017)

Do you have any idea of the flow rate? Rate of heat removal from the motor is simply flow rate, multiplied by temperature rise, multiplied by specific heat capacity. It might be informative to know how much heat is being moved.

It is true that pumping froth is not likely to be effective, but I assumed that the system was bled properly. Has anyone seen the appropriate Tesla service procedure, or is service documentation all secret?


----------



## Frank (Dec 6, 2008)

Agree: 2 degrees is not right...


----------



## Ada Diamonds (Feb 9, 2018)

Is it possible that you're getting boiling creating air pockets when you're running 150-170C? 50/50 Dexcool boils at 129.4C at 15PSI.

What oil/water heat exchanger are you running? Have you looked into Laminova exchangers? They're heavily used in F1, Koenigsegg, etc.

Great project!

JP


----------



## brian_ (Feb 7, 2017)

tiger82 said:


> *Motor Cooling*.
> ...
> The Tesla stator/rotor/power electronics are water cooled. Despite having a very high capacity cooling system and an ice reservoir, we were not able to keep the stator temperatures down. (There were no problems with inverter temperatures). This year, we will be experimenting with oil bath cooling of the stator/rotor air gap in addition to the water cooling. We will utilize a water/oil heat exchanger and a positive displacement gear pump to circulate ATF.


In the _Tesla Small Drive Unit_ discussion, it became apparent that the motor is *oil-cooled*, with the oil then transferring heat to the water (antifreeze) cooling loop. I realize that this is a large drive unit, but I'm guessing that the cooling system is fundamentally the same; if it is, the oil flow and heat transfer is critical. Do you have oil temperatures at useful points, such as in and out of the heat exchanger?

It sounds like heat from the stator transfers poorly to the water because the oil cooling system (if it is like the small drive unit) is not sufficiently effective. That would mean that there is potential for improvement in both the oil-to-water heat exchanger, and in oil flow at lower motor speeds (because the oil pump is gear-driven at a speed proportional to drive unit rotational speed), without adding a cooling system.


----------



## Ada Diamonds (Feb 9, 2018)

brian_ said:


> In the _Tesla Small Drive Unit_ discussion, it became apparent that the motor is *oil-cooled*, with the oil then transferring heat to the water (antifreeze) cooling loop. I realize that this is a large drive unit, but I'm guessing that the cooling system is fundamentally the same; if it is, the oil flow and heat transfer is critical. Do you have oil temperatures at useful points, such as in and out of the heat exchanger?
> 
> It sounds like heat from the stator transfers poorly to the water because the oil cooling system (if it is like the small drive unit) is not sufficiently effective. That would mean that there is potential for improvement in both the oil-to-water heat exchanger, and in oil flow at lower motor speeds (because the oil pump is gear-driven at a speed proportional to drive unit rotational speed), without adding a cooling system.


Brian-

Could a Laminova oil-to-water heat exchanger be deployed inline? AFAIK, their HEs are the best in the game: http://www.laminova.se/products/oil-coolers

(I'm a supplier to Koenigsegg, which uses these HEs)


----------



## brian_ (Feb 7, 2017)

Ada Diamonds said:


> Could a Laminova oil-to-water heat exchanger be deployed inline?


While a more effective oil-to-water heat exchanger might help - and Chris suggested replacing it in the other discussion - it wouldn't change the limitation of the motor-to-oil heat transfer.


----------



## GreenTecAuto (Jun 14, 2017)

Very interesting project! 
Loved the racing footage, particularly how you pass several other races at once.
Gotta love all that torque.
Never lets you down, 
Never gives up,
Never gonna run around and desert you... unless you are overheating or your batteries die, then it really makes you cry.

Something that also might help. I spoke with someone a while ago that was also putting his battery in high demands and had battery overheating problems.
Adding more does help, but you run into weight issues all over again.
What they did is have 2 packs. One on charge and the other in the vehicle. 
When needed, the battery was swapped out.
I dont know how practical that may be for you, but they designed their vehicle around replacing the pack quickly.
Also, I have a few of the Kia Soul packs.
As for the newer leaf packs, they are very difficult to find. Lots of demand for them.


----------



## tiger82 (Sep 23, 2015)

I see there are lots of replys going back a couple of months that I haven't responded to. 

I'm pretty sure that the water system has been bled properly. We have huge flow and V8 capable radiator. The problem is that the outer cooling jacket around the stator just can't remove heat fast enough. Under race conditions the stator temp goes up 12 to 20 degrees per lap. 

There is no oil cooling inside the large drive unit. The stator windings are encased in epoxy. The outer surface is in contact with the cooling jacket. The rotor has cooling water running through the center (Tesla has a patent on this). The only access we have inside the motor is via the air gap, or the ends of the rotor/stator.

During our testing we ran ATF or de-ionized water in the air gap. Unfortunately, the added heating provided by the fluid shear forces added more heat than it removed. We also tried spraying deionized water once the temperatures exceeded about 120 deC hoping that as the water flashed to steam it would provide a cooling effect. No success there either.

We did have some success when combing water spray with large amounts of compressed air, but the practicalities of implementing this are high.

We also considered CO2 injection but were concerned by the high stresses caused by the temperature differentials and the problems with carrying large CO2 tanks in a race car


----------



## Duncan (Dec 8, 2008)

Hi
Bringing this over from the Small Tesla motor discussions

If you are using the inbuilt pump you only get peak flow and cooling at max speed

I would suggest 
Use a small tank - 4 litres? as a buffer - internally split but with a weir so that so that if one side pumps more than the other it simply spills

One pump going from the "hot" side to the radiator - and back to the "cold" side

The other pump going from the "cold" side to the motor and back to the hot side

Both pumps need to be quite meaty - the idea is that they are pumping at the same pressure as the internal pump used to at max speed

When you drive it for part of the lap it will be heating up because it can't move the heat fast enough
But for part of the lap it will be cooling 

With the old motor pump the amount of cooling went up and down - with this set-up the cooling will stay at maximum - over the course of the lap you will reject more heat to the radiator than you used to

If the temperature keeps rising don't panic - as the system gets hotter it will be able to reject more heat - as long as it stays below the temperature that causes damage you should be OK


----------



## tiger82 (Sep 23, 2015)

Once again, the large drive unit has a different cooling system. The external water jacket and water to the center of the rotor are the only cooling mechanisms. There is no oil pump.


----------



## Duncan (Dec 8, 2008)

tiger82 said:


> Once again, the large drive unit has a different cooling system. The external water jacket and water to the center of the rotor are the only cooling mechanisms. There is no oil pump.


So what are you using for a water pump? - does it (or can it) run at full power all of the time?

And are you using a seperate water pump and a hot/cold well (tank) system for the radiator?


----------



## tiger82 (Sep 23, 2015)

We are using a Craig Davies electric water pump rated at 115 lpm. This runs at full speed all the time. As well as the radiator, we have an reservoir that holds about 20 litres. We can fill it with ice to pre-cool the motor to aboit 5 degC. This delays the time to power limiting by one or two laps. (Temperature rise per lap is in the range of 12-20 degC/lap).


----------



## brian_ (Feb 7, 2017)

tiger82 said:


> There is no oil cooling inside the large drive unit. The stator windings are encased in epoxy. The outer surface is in contact with the cooling jacket. The rotor has cooling water running through the center (Tesla has a patent on this). The only access we have inside the motor is via the air gap, or the ends of the rotor/stator.


Ah, so not like the small drive units. Thanks for the info, and sorry for the sidetrack.


----------



## Ada Diamonds (Feb 9, 2018)

Could you press aluminum, copper or polycrystalline diamond fins through the epoxy to touch the wiring of the stator to become heat pipes to move the heat from the stator into the fluid outside of the epoxy?

I assume that aluminum or copper would not work because they are electrically conductive but polycrystalline diamond could be the perfect material to excavate heat from the stator to the fluid.

For context, most epoxies are going to have a thermal conductivity of less than 1.0 W/Mk, where as a polycrystalline diamond that touches both the metal of the stator and the coolant can have a thermal conductivity of up to 2,000+ W/Mk. Cheaper diamond plates are 1,000 W/Mk

Thus a few (dozen) of these 10x10mm diamond plates ($245 each) placed through the epoxy might make a big difference in getting the waste heat out of the motor...

https://e6cvd.com/us/application/all/tm200-10-0x10-0x0-3mm-pl.html

Bulk Resistivity (Rv): 1x1012 Ohm cm
Surface Resistivity (Rs): 1x1010 Ohm cm
Thermal Conductivity: >2000 Wm-1 K-1 @293 K
Thermal Diffusivity: >11.1 @ 300 K (cm2s-1)


----------



## brian_ (Feb 7, 2017)

A green Tesla-powered Cobra race car just run the second-fastest time (of all 60 entrants) at the Knox Mountain Hill Climb. I'm guessing there can't be two of these cars in B.C... so *congratulations*! 

Knox Mountain Hill Climb
(Look for car #101 and #701 - for the same car with two drivers - in GTO class)

It looks like the motor temperature rise can be tolerated for one minute and fifty-one seconds of hard climbing.


----------



## Frank (Dec 6, 2008)

Congratulations!


----------



## tiger82 (Sep 23, 2015)

Thanks guys!


Here's a link to some in-car video. 

https://www.youtube.com/watch?v=f-QJXL3JEs8&t=13s


----------



## Frank (Dec 6, 2008)

Looks like fun! FWIW, You might be interested in "Dashware", it's a software package that can integrate video/GPS info to give added entertainment value to your videos.

Glad the car worked okay for you, hillclimbing will definitely find any weak points in a vehicle.


----------



## brian_ (Feb 7, 2017)

tiger82 said:


> Here's a link to some in-car video.
> 
> https://www.youtube.com/watch?v=f-QJXL3JEs8&t=13s


Thanks for sharing that. 

The lack of noise is bizarre for a competition video - wind noise nearly completely covers both motor/gear whine and tire sounds. I was expecting to hear both the drive unit (varying with road speed) and the tires (at highest lateral load).

It looks like there were a couple of "interesting" moments there with loss of rear traction on corner exits.


----------



## [email protected] (Jul 2, 2018)

hi tiger, i'm interresting in using a kia battery pack in my next project.
i have the battery pack but without the car, so i can't work on a full fonctionnal can bus.
do you have any information on the can string from the bms ?
i may be interrested in used the original kia charger too.


----------



## tiger82 (Sep 23, 2015)

Depending on what you want to do, you can just use Torque Pro. You can monitor all variables including individual cell voltages, pack temperatures, current, SOC etc. If you need to actually work with the data, you need to be able to generate multi-frame OBDII messages. We did that in our datalogger. It involves sending a CAN query string, waiting for a response, sending an ACK, then receiving and parsing 62 bytes of data. I can supply some sample code if you want. 

If you want to utilize the onboard charger, we have some recorded CAN traffic that you can replay in an endless loop that will fool the charger into starting up. I can also send that to you if you want.


----------



## [email protected] (Jul 2, 2018)

thanks tiger82 for your answer.
i'm realy interrested in your sample code, and CAN trafic for the charger.


----------



## Reid_in_QC (Sep 5, 2017)

I'm interested in the pack. More Soul EVs on the road, more finding their way to the scrapyard.

I might have a lead on one locally but don't know the pack. I've worked with Volt packs in the past and some oddball BAE modules so I'm getting the hang of this stuff gradually.

The Soul pack seems to be stacks of NMC pouch cells. Apparently air cooled which is a plus for me, simplicity-wise. Does it break down well? Can you break it down into individual bricks and reorganize as you wish or are there just small stacks and tall stacks and that's it?

And what's it worth used do you reckon?

If someone knows of a good link to Soul pack info elsewhere let me know. I'll keep hunting.

Oh, and your project is SPECTACULAR!

~ reid


----------



## GreenTecAuto (Jun 14, 2017)

The modules inside are pretty interesting.
Each BMS tap is fused for 2A with a standard car fuse.
The pack does come apart and the cells can be removed, but 2 cells are welded together in parallel.
Here are the two types of modules in the car with the pictures of how they break down.

It also looks like you can take 2 modules and construct them into one larger module of however many cells you need, but in order to do that, you need to remove the BMS voltage tap assembly. They are spot welded together.

14s pack
https://www.ebay.com/itm/Kia-Soul-4...AOSw1ExcEpOo:sc:FedExHomeDelivery!66062!US!-1
10s pack
https://www.ebay.com/itm/223282094685


----------



## brian_ (Feb 7, 2017)

Reid_in_QC said:


> If someone knows of a good link to Soul pack info elsewhere let me know.


This is the most useful that I have seen... that doesn't mean much, but it might help:
Comparing layout of the Soul EV battery with other EVs

Apparently pouch cells with polymer electrolyte and NMC cathode, forced air cooled.

While this car has moved on to a custom pack using Chevrolet Bolt cells, the original Soul battery pack seems to have been used complete and essentially intact, "folded" down the centre line so sides of the modules which were originally facing up now face left and right. Right?


----------



## [email protected] (Jul 2, 2018)

here some photo of a 30kwh usable pack from a 2018 one.
it have 100cell, 16s X2 , 14s X2 and 10s X4 .
you can see on the last one the electric heater.


----------



## ElectricSpeedShop (Dec 4, 2018)

Really great work! Love the idea and the final result! Any interest in featuring your build on my blog? I have interviewed other people about their custom EV/ conversions if you want to see an example. Let me know! Will send a PM as well!


----------



## NiallDarwin (Sep 29, 2018)

I'm really impressed by this build and by the level of helpful technical comments. What a great community.


----------



## Electric A1 (Oct 16, 2016)

tiger82 said:


> Depending on what you want to do, you can just use Torque Pro. You can monitor all variables including individual cell voltages, pack temperatures, current, SOC etc. If you need to actually work with the data, you need to be able to generate multi-frame OBDII messages. We did that in our datalogger. It involves sending a CAN query string, waiting for a response, sending an ACK, then receiving and parsing 62 bytes of data. I can supply some sample code if you want.
> 
> If you want to utilize the onboard charger, we have some recorded CAN traffic that you can replay in an endless loop that will fool the charger into starting up. I can also send that to you if you want.


Wow, this is a really neat build! I'm looking at using one of these Kia Soul packs to use in my 2000 Ford Ranger EV. So far, your project is the only one I've been able to find that has used a Soul EV pack...
I actually caught your email at the end of the video on your Youtube channel and sent an email to you.
Is there any way you could send me the sample code for using the BMS and onboard charger? What modifications did you need to do in order to re-use the original BMS from the Kia? 
I'm basically trying to look for all the info I can possibly get on using these packs, haha.


----------



## mpobor (Jul 9, 2018)

Hi all!!! Im looking for a kia soul battery on scrape yard ... Im trying to build the conversion with less money possible... Im reading that someone crack the code to re use the charger and the bms of the soul..


Who can i contat ct to trying to get this code??? It will definetely help with saving money on bms and charging!!!!!

But i dont know who i can reach to help!!!


----------



## tiger82 (Sep 23, 2015)

I thought everybody might be interested in an update. This YouTube video summarizes our last 4 years of development and our move to a Tesla Model 3 drive unit and battery pack.


----------



## brian_ (Feb 7, 2017)

tiger82 said:


> I thought everybody might be interested in an update.


Yes! Thanks. 

For anyone who has suggested using Model 3 battery modules, I encourage them to look at the size of this pack, rearranged as one stack of all four modules extending from the front axle line (ahead of where the front the engine would be in this car)








...to what would be the passenger seatback if there were room left for a passenger:








Of course in this stacked arrangement they are higher than they would be in a stock Model 3, despite being in a race car... but getting them in the car at all is impressive. 

It's interesting that the Model S motor has no more continuous power capability (due to the cooling limitations) than the motors from ordinary economy EVs.

I hope that people now realize that the Model 3 is not a switched reluctance motor. It is, like most EV motors introduced over the past decade, a synchronous (not switched) reluctance and internal permanent magnet (IPM) design. Elon Musk called it a switched reluctance motor early on (presumably seeing "SR" in some briefing notes and not understanding the difference), and the myth has stuck.

I always thought that this car really should have the motor ahead of the axle line, as explained in the video, but I certainly understanding starting with the Model S drive unit, based on availability of the drive unit and aftermarket support. It's good to hear that the cooling is much better than in the Model S unit, probably to a substantial extent to the lower heating in the IPM/reluctance rotor compared to an induction rotor.


----------



## CantDecide (Oct 20, 2019)

tiger82 said:


> our move to a Tesla Model 3 drive unit


What are you using to control the Model 3 drive unit?


----------



## tiger82 (Sep 23, 2015)

The CAN bus based controller is from Ingenext: Ingenext - EV Conversion, Used EV Parts, Tesla modifications


----------



## CantDecide (Oct 20, 2019)

wow great, I didn't realize there were any 3rd party solutions to control the Model 3 motor yet. The website isn't clear but it sounds like if you want control over regen and maximum motor power you need to use a model 3 battery pack as well. Is that true?


----------



## brian_ (Feb 7, 2017)

CantDecide said:


> The website isn't clear but it sounds like if you want control over regen and maximum motor power you need to use a model 3 battery pack as well. Is that true?


I'm only taking a somewhat informed guess from reading their website, but if you are referring to the "Boost 50" product, this is for an intact Model 3 rather than DIY use of Model 3 components - it would work by intercepting messages between components and replacing them with faked messages that omit the information that stock system uses to limit power to protect the battery. The base controller for DIY use probably allows the same higher power level and unrestricted regen, not caring if you fry the battery. But you should check with Ingenext for the real answer.


----------



## brian_ (Feb 7, 2017)

Stay tuned for the next upgrade to a Model S Plaid rear drive unit, in a couple of years, right?


----------



## CantDecide (Oct 20, 2019)

brian_ said:


> I'm only taking a somewhat informed guess from reading their website, but if you are referring to the "Boost 50" product, this is for an intact Model 3 rather than DIY use of Model 3 components


No, I'm referring to their battery and motor controller: TESLA MODEL 3/Y BATTERY & MOTOR CONTROLLER

This is the part that confuses me, its just the right combination of badly written and too high level to understand:



> *MOTOR CONTROLLER (Drive Inverter)*
> The Motor can be controlled in 2 different ways for the functions: *drive*, *reverse*, *park*, *creep* and *regen.
> 1*. The first way is by *CAN bus* which will be provided with a CAN data base. This data base allows to receive live data like speed, power, regen, voltage, temperatures. It also allows the control of several limitations such as maximum power, regen by braking and more. Works only with battery & motor controller
> 
> *2.* The second way is with *digital inputs* to control PRND, creep and regen with buttons. There are also outputs to turn on reverse and brake lights. Works only for the motor controller.


----------



## SuperV8 (Jan 22, 2020)

brian_ said:


> Stay tuned for the next upgrade to a Model S Plaid rear drive unit, in a couple of years, right?



Plaid Rear Motor


----------



## brian_ (Feb 7, 2017)

SuperV8 said:


> Plaid Rear Motor


As the description says, that's the whole drive unit: two motors and two reduction gearboxes. It doesn't appear to include the inverters, but that's only a guess. Less than $10K USD - not bad!


----------



## SuperV8 (Jan 22, 2020)

brian_ said:


> As the description says, that's the whole drive unit: two motors and two reduction gearboxes. It doesn't appear to include the inverters, but that's only a guess. Less than $10K USD - not bad!


Yes, the Inverter is listed separately:
$1010 again seems quite reasonable! However both are 'restricted' so suspect actually buying one without a broken Plaid car may be difficult?
Looks similar to the Model 3 Inverter in design with Silicon Carbide. Only lists the Qty as x1 - so could 1 inverter control both rear motors? 


The best value through looks like the long range rear motor at 'only' $2.5k - again looks 'similar' to the Model 3 to me?


Interestingly the Plaid Inverter is cheaper than the LR


----------



## brian_ (Feb 7, 2017)

SuperV8 said:


> Yes, the Inverter is listed separately:
> $1010 again seems quite reasonable! However both are 'restricted' so suspect actually buying one without a broken Plaid car may be difficult?


Yes, "restricted" presumably means you can only buy it as a replacement for your Tesla - they may even want the old unit back in exchange to keep owners from buying them on behalf of other people.

The new listings are great to describe the parts; the only actual source of major Tesla parts is salvage from wrecked cars.



SuperV8 said:


> Looks similar to the Model 3 Inverter in design with Silicon Carbide. Only lists the Qty as x1 - so could 1 inverter control both rear motors?


That's one unit (box), containing two independent inverters. It is not possible to run two synchronous motors that are not mechanically linked together from one inverter, and even when two motors are mounted on the same shaft, they normally get their own inverters. Even with a different motor type (e.g. induction) you wouldn't want a single control of two motors; the ability to individually control the torque to the two wheels at the same axle is most of the reason for using two motors - it's marketed as "torque vectoring".



SuperV8 said:


> The best value through looks like the long range rear motor at 'only' $2.5k - again looks 'similar' to the Model 3 to me?


It could be, like the front motor in the current AWD Model S, but even more similar to the Model 3 rear package. It looks much like the small rear induction drive unit, but the illustration on the Tesla website's Model S page shows that the motor is ahead of the axle line, just like the Model 3 (not behind the axle line like all of Tesla's induction motors). If only one could buy them this way it does look like they would be a good deal... and since Tesla has owners captive for these parts, I don't know why Tesla isn't charging more. Of course, they rarely fail, so few would be sold and so the price doesn't matter much.


But I'm sure that tiger82 isn't actually shopping for a next generation of powertrain for the Cobra, so this discussion should really be in a different thread.


----------

