What motor for 2WD - the fastest?

[joffacn]

Brushless motors:

Why are most setups for 2WD and 4WD using different Kv (turn) motors?

With the ability of high end ESC's and Tx's to tune the throttle response would not the fastest motor be the best - then adjust the pinion for the fastest section of track and tune in the response to the throttle to suit the traction? OR tune the thumb .

There should be no problem with run time using Brushless and Lipos.

My Cyclone D4 runs a Mamba 6900 combo with 17t pinion on a small grass track.

What to run in a D2?

Thanks Jeff