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Old 10-10-2012, 02:03 PM   #74 (permalink)
RE_Farmer
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Quote:
Originally Posted by samway47 View Post
I have a Chevy s-10, lead sled(4500 lb.) running a 9in. motor. Top end on dc motors are usually around 5500 rpm. Check with Warp, but I think you'll find that you need to run around 4000 rpm and that you are hurting the motor and creating excess heat buy running at low rpms. If you can get your car on a chassis dynomometer you will see exactly where your torque drops off and when to shift.
Samway, you're right about motor speed and heat. The Warp9 hp peaks ~3500-4000rpm. Yes, series DC motors do make max torque @ 0 rpm, but they also make max heat. One needs to spin these motor up to get rid of the heat AND to clear out the brushes' carbon dust.

There was a guy at EVCCON that trashed his motor. George Hamstra took a look at it and thinks it might have been due to excessive carbon dust shorting the motor. To ameliorate the heat, you need to keep the revs up and, or at least add an external blower to cool the motor at low to zero rpm and clear the brush dust.
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