# Question about front engine/rear transaxle



## electric! (Sep 3, 2011)

I recently bought a car with this configuration. If i were to use this as a conversion car, how wise would it be to mount the motor in the rear of the vehicle, directly into the transmission?

I imagine i'll be removing the rear seats, building an enclosure for batteries, and making kind of a mid-engine design. This will also cut a lot of wiring out of the equation, since the batteries, motor, and presumably charger will all be close to the old gas port, which will be my plug-in location.

Thoughts on this design? Has anybody executed a similar layout?


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## ken will (Dec 19, 2009)

If I had a car with a trans-axle, that is what I would do.
What car do you have?


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## rwaudio (May 22, 2008)

I'm doing a Porsche 944 with that layout, the only concern I would have is if you are putting too much weight on the rear axle. Otherwise I think it's a good idea. I have a front motor/controller, rear transaxle and rear battery pack. I will have two main wires running to the front to the controller but I doubt it will have much impact on efficiency or power.


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## ken will (Dec 19, 2009)

rwaudio said:


> I'm doing a Porsche 944 with that layout, the only concern I would have is if you are putting too much weight on the rear axle.


Mount the motor to the front of the trans-axle with the controller just in front of the motor. To keep the weight distibution as close as possible to stock, mount the batteries where the old ICE motor was. Run the power cables in the drive shaft housing. It looks like it will be about 3 or 4 ft. from the batteries to the controller


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## rwaudio (May 22, 2008)

ken will said:


> Mount the motor to the front of the trans-axle with the controller just in front of the motor. To keep the weight distibution as close as possible to stock, mount the batteries where the old ICE motor was. Run the power cables in the drive shaft housing. It looks like it will be about 3 or 4 ft. from the batteries to the controller


I never noticed it before, but it looks like they left out the bell housing for the flywheel/clutch at the rear of the engine on that "mockup".

But on topic, unless you wanted to do a TON of cutting and relocate the shift linkage there is no way a motor would fit in front of the transaxle. The tunnel is just too small, and making it larger would be very intrusive to the interior. A very short motor might end before the front seats and leave them intact. If I was going to attempt a rear motor I would be flipping the transmission and stick the motor out the back like a VW.


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## DavidDymaxion (Dec 1, 2008)

I had thought myself that would be a great layout for an EV and considered doing it myself years ago with a 924S. The newer Corvettes offer this possibility, too.

Anyway, here are some thoughts:


An electric motor is much larger diameter than the driveshaft, so you'd probably have to cut the center tunnel. The center tunnel is a major strength member of the car.
You'd have to be careful the expensive motor didn't become the car's low point and get damaged by a speed bump.
If the motor is near a hole in the tunnel, like the shifter hole, an overspeed could fling comm bars at the driver -- I'd make sure an NHRA grade scatter shield was between the driver and the motors (maybe the specs possibly met by the tunnels' sheet metal?).


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