EV drivetrain options

Hello all,

First off, I’m new; both to this forum and to EVs in general. So I apologize ahead of time - I’m sure I’ll throw a bunch of newby questions at you.

I read Leitman and Brant’s [I]Build Your Own Electric Vehicle[/I], and, like all good how-to books, I have more questions now than when I began. The book discusses marrying an electric motor to a manual trans, but is that necessary? In other words, can an EV builder bypass the transmission and join the motor shaft directly to the differential? For example, can I hook up an FBI-4001 to the yoke on a Ford 9in rear end and bypass the transmission and drive shaft? For that matter, could I hook up a motor to each rear spindle and eliminate the diff as well?


yes its possible . its just less common due to less flexablity that multiple gears ratios give.

Has anyone seen examples of this? Would it take a specific controller, or multiple controllers in the case of separate motors for each wheel?

My goal is to start on an EV project in the next year or so. I’m going for something with as few parts as possible; something that will go FOREVER. That said, I like the idea of ditching the trans and drive shaft as well as the engine… less pieces to break.


It all depends on the final gear ratio. If your motor can operate at the road speeds that you want while staying in the motor’s recommended operating speed, you could use only a differential for gear reduction.

If you wanted to eliminate the differential, there might be a problem of slippage between the drive wheels in tight turns causing a scrubbing of the tires–kind of jerking or stuttering around the corner. Also, the final gear ratio might make it difficult for the motor to stay in its recommended speed range.

I hope that I was helpful.

When this is done a AC motor is used, My idea when my truck engine goes out is to mount tne AC motor in the bed and rotate the axle 90 degrees and then couple the motor directly to the pumkin.

[QUOTE=new dawn;6223]When this is done a AC motor is used, My idea when my truck engine goes out is to mount tne AC motor in the bed and rotate the axle 90 degrees and then couple the motor directly to the pumkin.[/QUOTE]

Do air cooled AC motors exist for such an application? All the AC motors I’ve seen are liquid cooled. One of the things I like so much about an electric powertrain is that one can dispense with not only the engine, but also the radiator, coolant pumps, hoses, etc. I figure EVs to be inherently more reliable because of their relative simplicity and absence of numerous parts to break.

The Tango 600 uses dual advance dc motors paired with their own gear boxes. I haven’t the foggiest what those gear boxes would cost to reproduce, but I’m sure it’s not cheap. I’ve heared of people making their own gear boxes, but I’ve never done such a thing, and wouldn’t know what it entails. If anyone has any info on the subject, I’m all ears (well, all eyes I guess…)

BTW, thanks for all the input. I’m learning a ton!

Brushless Dc technology is best suited for drive trains… due to their high power density

I would like to get first hand (or second hand) knowledge, from someone that used a snow mobile CVT on a lightweight EV.

My vehicle specs:
approx. 1800lbs
3 wheel tadpole design (rear single wheel)
Warp 9 or TransWarp 9 motor (not both)
Zilla 1K-EHV
battery pack 144V - 40 to 60Ah
intended max speed: 85mph
intended range: 30+ miles
intended acceleration: Very good.

Option 1:
Rear wheel powered via CVT. Motor located in rear area. leaves lots of room for batts in front. The springs on the clutch would be eliminated, so that engagement is at 0 RPM.

Option 2:
Front wheel powered via VW tranny. Motor located in front as well. Most battery packs would have to be custom sized for locations.

Option 1 would be easier and cleaner for me. However, I have not heard from a single person that has done this before with similiar specs as mine.

Can anyone chime in here?