# Direct to drive... Which Motor is best?



## madderscience (Jun 28, 2008)

You will need a lot of torque, so don't go with less than an ADC or warp 9". You will need at least a 1000A controller to back it up. The other thing to look at doing is make sure you have a high ratio axle, like 4.77:1 or so.

Good Luck.


----------



## steven4601 (Nov 11, 2010)

If you'd consider going AC, get A high pole count motor. 
Pole count trade speed for torque.


----------



## rlewis96 (May 2, 2011)

steven4601 said:


> If you'd consider going AC, get A high pole count motor.
> Pole count trade speed for torque.


I defiantly want to go with an AC Motor for the brake regeneration... How high of a pole count would you suggest?


----------



## peggus (Feb 18, 2008)

Higher pole count doesn't increase torque, when all else is the same.

The torque is a function of the dimensions of the air gap and flux, pole count doesn't factor into it.

More poles increase torque only if the radius of the air gap also increase.

For direct drive I agree with madder, 9-11" DC with 1000A controller. Bigger is better, also add forced air cooling.


----------



## Yabert (Feb 7, 2010)

rlewis96 said:


> the only problem then is what motor to use?


And what about the reduction ratio you need to take the motor in his sweet RPM?
Do you build gearbox? Or do you have a rwd celica?


----------



## Haggerty (Jun 9, 2010)

I've been considering building a direct drive vehicle as well.
From what I understand a RWD application would be best suited for it. You remove the transmission but you retain the differential which in most cases is easy to change the gearing. You'll want to find the optimal rpm for the motor and pick a gearing that will convert that to your expected cruise speed. You'll need torque and amps to get moving initially, as long as you stay light you should be fine.

I'm actually looking into direct drive AWD applications.


----------



## rlewis96 (May 2, 2011)

Haggerty said:


> You'll want to find the optimal rpm for the motor and pick a gearing that will convert that to your expected cruise speed. You'll need torque and amps to get moving initially, as long as you stay light you should be fine.
> 
> I'm actually looking into direct drive AWD applications.


Removing the transmission and the engine would be roughly 300lb to 400lbs of weight off the car... however, I still need to consider the weight of the batteries I use, the motor, controller, etc. Having a lighter EV is my main goal in all of this... I want to be able to not put a lot of strain on the motor, as well as, keeping it light...


----------

