# Direct Drive



## major (Apr 4, 2008)

dark7622 said:


> Would there be a need for a transmission? I understand this puts more work on the motor and brushes, just was wondering.


The use of a multiple ratio gearbox is up to you. It depends on the vehicle and performance objectives and the rest of the system, like controller. And yes, direct drive can run the motor at higher current longer than if you were to select a lower gear (higher ratio numerically). Direct drive will also tend to run the motor at lower RPM for slow vehicle speed (mph) which then can necessitate forced motor cooling.

Note that most, if not all, of the top performing electric drag racers run direct drive. A few have recently started using overdrive units.


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## bjfreeman (Dec 7, 2011)

Transmission is more like a range selector, in the fact there is not much shifting, except for grade changes, and first acceleration. I use a Manual, that I only changed for starting on hills, and overdrive for high speed driving. This is because the motor is under rated to do direct drive, for the Vehicle I have.


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## dark7622 (Jul 3, 2008)

Hmmm I've seen some figures, I'm looking at converting a very old car (1950) to an EV, but the total weight is at 3650lbs. to do direct drive I would need to do two motors cuppled together. Though I wonder since I think the motor it's self (inline flat 8CLINDer) weighs probably 1k or so with the tranny. 

My main goal is do do drive by wire along with the EV, I want the car to be real unique you know. 

Problem with a tranny is the shifter and shifter pattern, drive by wire isn't geared to playing with a shifter.

I've thought of maybe a couple of actulators to control the shifting but just seems like too much BS. Any one know of an elec controled manual transmission?

3 motors brand new is like 10k to run them together for such a heavy car.

Any idea's

Joe


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## Ivansgarage (Sep 3, 2011)

Take a look at this, 7000 lbs vehicle, 4l60e trans..
http://topekaelectricmotor.com/electric-vehicles/ac-project

Here is the motor specs.
http://topekaelectricmotor.com/files/Baldor-Motor-and-Curtis-123.jpg

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## bjfreeman (Dec 7, 2011)

dark7622 said:


> Hmmm I've seen some figures, I'm looking at converting a very old car (1950) to an EV, but the total weight is at 3650lbs. to do direct drive I would need to do two motors cuppled together. Though I wonder since I think the motor it's self (inline flat 8CLINDer) weighs probably 1k or so with the tranny.
> 
> My main goal is do do drive by wire along with the EV, I want the car to be real unique you know.


mine is a 1950 30ft Bus, 1500lb on the back axle, 1000 lbs on the front axle. it has been my own brand of fly-by-wire before I went EV. use Joystick that control's the speed, direction, and braking.



> Problem with a tranny is the shifter and shifter pattern, drive by wire isn't geared to playing with a shifter.
> 
> I've thought of maybe a couple of actulators to control the shifting but just seems like too much BS. Any one know of an elec controled manual transmission?


I don't shift that much, it is still manual. I do have buttons that the system matches the motor and speed based on the gear I am shifting to


> 3 motors brand new is like 10k to run them together for such a heavy car.
> 
> Any idea's
> 
> Joe


I have a 250KW motor and eventually will have one on each wheel.


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