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Discussion Starter #1 (Edited)
Electric motors by nature are very torquey and normally have more torque that horsepower. I was thinking about how Honda engines have very low torque and have to be revved to the stratosphere to get max power out of them. I was curious as to if an electric motor be engineered to mimic this. Vtec motors also very fuel efficient and I was curious if this would mean that those electric motors would use less battery power.
 

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VTEC engines might be efficient compared to a V8 of the same output, but that's not really how us Europeans see those screamers.

Yes, lower torque , higher rpm motors exist, but there will still be flat torque from 0rpm to whatever max power comes in at. Part of the VTEC experience is the step in torque delivery you get at 4000rpm when the second cam profile kicks in.

As regards what makes a higher revving motor, well part of that is voltage, the higher the rpm, the more voltage it takes to maintain max torque. In a DC motor the commutator/brushes have their voltage limits i believe. With AC, you might need thicker insulation on the coils of wire the electromagnets. This means you can fit fewer turns of wire per coil, so torque goes down a little.

Motor design is of course the biggest factor, though the physics elude me. Again, it has a lot to do with how many turns of wire you put on the coils. More turns of thinner wire or fewer turns of heavier gauge stuff. One choice improves the amount of torque you get for a given current, the other reduces the rate that voltage rises with RPM, allowing you to make peak power at higher revs. Naturally one always comes at the expense of the other, i just can't remember which way round it is.

I think the main thing about using higher rpm/voltage motors is saving size/weight. What's the diameter of the Tesla model S motor? It looks tiny, but it puts out so much power compared with AC50 and similar.
 
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