RX7
Simply stated: HP = Torque x RPM ÷ 5252. HP and torque are intimately related.
Since a motor has close to full torque at 0 speed, no transmission is necessary.
I think 32-35 hp for 70 MPH is about right for a Locost book chassis, slightly more that that for a 442 chassis as it has a larger area to push down the road. Bear in mind that in Jacks case, the transmission looses some energy that a non-trans vehicle would then have available to push the car (less mechanical loss). That is for continuous operation. For longevity, one should de-rate the electric motor some amount so maybe use a 40HP motor?
Assuming a engine-generator set for long term hauling, the engine for the generator might be ~110-120% higher than the 35HP in order to account for conversion losses. The generator itself would have to be appropriately sized for continuous operation; slightly over 26KW.
This is all somewhat theoretical.[/quote]
Thanks,
I agree with your points regarding the transmission and when I was contemplating to turn my first locost to electric this is where my mind was. For what it's worth however I was told by most of the folks who have done conversions (including vendors) that an electric car with a transmission will be more versatile; ie will get to highway speed more easily and offer better regenerative power downhill. Direct drive however will work and save weight.