DIY Electric Car Forums banner

Porsche 911 (996) Tesla Swap

11509 29
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.
1 - 5 of 5 Posts

· Registered
Joined
·
252 Posts
Looks like there are some conversions out there, where the Model 3 motor got installed upside down, so that the motor sits behind the diff, like its the case for the Model S motor.

I am also planning a 991 conversion (993 in my case) and would prefer the M3 DU. But I think installing it upside down is not the best idea. E.g. the Oil pump will be sitting at the highest point, so I will probably end up with a large Model S DU.
 

· Registered
Joined
·
252 Posts
I'm anxious to take some measurements once the engine and trans is pulled out of the 996. I'm really hoping there is enough room for the Model 3 rear drive unit ahead of the rear axle. I know the 993 is a bit smaller than the 996. I'll post some pictures here with the tape measure underneath to see if that Model 3 unit will fit, maybe it will help you out. Also, I know you have to have that oil pump at the bottom.

I think the 993 is one of the best looking cars out there. Do you have one with a blown motor?
Crossing my fingers :) if it doesn't fit in your car, it wont fit in mine for sure...
I bought a 993 with missing engine, transmission, speedo, DME and some other stuff, so perfect for a conversion. Its still in the container in the US and waiting for sailing to Europe. This container shortage is very annoying. Latest ETA is Christmas.

I guess I will open another thread to not hijack yours :)
 

· Registered
Joined
·
252 Posts
Nice Video :)
The B Class Battery is an awesome pack. Have one here, its a strange form factor, but quite compact. Unfortunately its only 84s, so the optimal voltage for the Tesla DU's (96s) is not reached. Maybe one could use one pack plus two modules. But hard to source two similar old packs. Also only will be able to do 3/4th of the current of the M3 DU.
Its a good pack for a bug, but for a Porsche the power of the M3 DU should be used :)

Its really not easy to find a compact pack for it. My conclusion was to use either a BMW i3 pack or VW ID3 battery. Both are 96s and nice OEM Modules. i3 Pack prices are going through the roof in Europe, though.
Also a Model 3 LFP was offered to me, but from the Munro video it looks like the Modules can't be taken apart easily.

If it should be really cheap and range doesn't matter, the Chevrolet Volt hybrid pack would be good. But for me that would be too low range.
 

· Registered
Joined
·
252 Posts
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:
 
1 - 5 of 5 Posts
Top