[barrkel]

A flat torque curve means you get more power at higher revs. Power = torque x revs.

If torque is the same at 5k revs vs 10k (to pick numbers from thin air), when you downgear 10k 2:1, you double the effective torque over 5k at 1:1, for the same output revs.

[aetherspawn]

It does not work like that. To run twice the speed, you run twice the voltage so you run half the amps. Torque scales almost linearly with amps. With the same power input, the power output is all about the motors limits versus your conversion efficiency.

The battery layout and chemistry will limit the actual power that can be delivered to the powertrain (discharge rate). A faster electric car is not one geared higher, but one which converts the most of this energy into motion.