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Porsche 911 (996) Tesla Swap

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Hello Folks,

Next week, I will begin pulling the engine out of a 1999 Porsche 911 C4 so that I can start an EV conversion project. I've done multiple engine swaps and have a good basic understanding of circuits. Plus, I've been watching a good amount of YouTube, including some of Rich Rebuilds Mini Cooper conversion series, so I got that going for me.

I would like to use the Tesla Model 3 Rear Drive unit from the standard range car (will be ditching the awd system). My understanding is that the Model 3s use a new motor type with more efficiency. I believe it is referred to as a Internal Permanent Magnet-Synchronous Reluctance Motor. Anyway, I figure, the Model 3 Standard Range does 0-60 in about 5 seconds and weighs about 700 pounds more than what this should weigh when it's done, so the standard range motor should be enough power.

Question for anyone who might know: Is the rear drive unit in the Model 3 Standard Range, the same as what comes in the Long Range/ Performance model?

Battery Range: I would be happy with 40kWh here, I figure that would give me about ~140 mile range, and not add too much weight.

I'm cheap. I hope to do the entire swap for around $10k (this takes into account getting some money back from selling Porsche parts). This means I probably will be looking for something other than Tesla battery modules.

I got to speak with Michael Bream at EV West today, he brought up a good point that the Model 3 motor places the axles behind the electric motor, thus transferring some weight forward in the car, whereas the Model S and Model X motors place the electric motor behind the rear axle (like a 911 engine sits). I figure I will be adding battery pack weight to the back of the car so the Model 3 motor would be okay.

I have heard that the Model 3 motor is newer for swaps and so people are still working on motor controllers and things like this. I'm all ears to any advice or information you think would be helpful.

YouTube video of the car I'll be swapping and some initial thoughts:
Ebay Listing for Model 3 Motor: 2020 Tesla Model 3 Rear Drive Electric Drivetrain Engine Motor Unit | eBay

Picture of the 911 being swapped.
Wheel Tire Car Vehicle Hood

Thanks for reading this. This is a dream project of mine and has taken a while to even get to this point.
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Discussion Starter · #21 ·
Hi All, I've been making slow progress on the Porsche 996 Tesla swap. I received the Tesla Model S rear SDU last week and am starting to play around with mounting it. I also learned quite a bit talking to Kevin Erickson (who owns a swapped Plymouth Satellite and won some awards at Holley High Voltage) about batteries and controllers. After talking with him, I am leaning toward Nissan Leaf modules for this project and cooling them with air by spacing the modules with gaps in between and using a big fan and drawing air through the battery box. Kevin said the bigger issue when wanting to pull power from any pack is that they need to be warm (but not too warm). I also really like the idea of air cooling them to keep it simple and light. He just switched from the ZeroEV controller to EV Controls and loves it. Here's an update video with some of our conversation. Thanks again to this community for the support and help you are providing!

 

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Kevin said the bigger issue when wanting to pull power from any pack is that they need to be warm (but not too warm).
You will probably find tiger82's comments about battery temperature and performance interesting:
Pre-heating the pack certainly helps performance for the first session of the day...
More details about the car and its performance are in the builder's threads:
Tesla Powered Cobra Race Car
Modified Bolt Pack for Tesla Cobra EV Race Car
Model 3 Battery Pack for Tesla Cobra EV

I also really like the idea of air cooling them to keep it simple and light.
Direct air-cooling is simple and light, but not very effective. It may be good enough.
 

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Discussion Starter · #24 ·
Hi All, I bought a wrecked Nissan Leaf and I don't know the state of the battery. Yes, it was a risky buy. The dash doesn't tell me anything about the battery so I'm guessing something like Leaf Spy won't either, but I want to try. It seems that the Leaf Spy app for iPhone is $20 now and there is no free version? I'm guessing this is the best app and worth the $20? I just ordered a popular bluetooth OBD scanner. We will see. Here's the most recent video in the build series if you are interested. It shows the unloading of the wrecked Nissan Leaf donor car. Big shout out to @Electric Land Cruiser for picking this car up in Portland!

 

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LEAFSpy is totally worth the $20. You can use it for all sorts of LEAF type stuff like pairing a replacement battery and viewing the exact Ah and charge cycles on the battery.

Also bummer about the Chademo lid haha. They always break so easily.
 

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That video ^^^^ has an interesting take by Kevin Erickson on the EV Controls vcu
Thank you, yeap it gets expensive pushing hardware into untested territory. Part of the reason for doing dual DUs is to sneak up on things slowly by putting one motor in drive and one in regen. Equally I can build a test rig that couples the axles together with a torque arm and properly qualify things under load before going in the car.
 

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Still can't say what motor will fit and if one of the Tesla DU's will fit at all. Battery space will vary depending on the motor selection. So I am still trying to plan the conversion, but it looks like it doesn't make sense to plan without having the car here.
Have you been able to measure the space for motor and Battery already?
At least on the 993, neither the M3 Motor, nor the large Model s motor does fit. M3 DU doesn’t fit die to the rear seats, the large S DU due to the subframe that’s carrying the suspension.
Looks like the small S DU does fit, but I only tested with the subframe parts, as the car is on the way, still.
Will be very interesting to see if the 996 is that much larger that one of the other DUs fit. Crossing my fingers!!

here some info about the leaf packs:
Hi Mark, I am new to the forum and have been trying to find info on a Tesla Small DU fitting into a 993. I just picked up a 993 cab that I plan to convert. How is yours progressing? Would you be able share any info with me? Thank you!
-Josh
 

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Discussion Starter · #30 ·
Hi All, I realize I have not posted for a while. That Nissan Leaf I bought arrived with no battery. That was a major bummer! I have since sold that car. I built motor mounts for the Tesla SDU this summer. I'll put a link to that video below. The Porsche has sort of been sitting since the summer because I have been searching for a battery pack and I got some other projects. Ideally, I'm looking for a pack with 30-35kwh, will be able to provide good power to the SDU and is lightish. I'm open to buying something slightly used if it were a good fit.
Making Custom Tesla Motor Mounts
 
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