well i know about brushless. i run an lrp system in a TC. a mamba max 4600 in a DF-03, and a vxl system in a rustler. and for a while it was in a maxx. so if i go with the 7xl ill have decent speeds and enough torque to lift the tires off the ground on 3s. and once i can step up to 4s it will be insane? more in the 40-50 range than the 35-40 range?
I can say that a 7xl on 4s is a fast setup. I gear all of my vehicles for around 40 so It all depends on motor speed. Keep the motor speed below 40k rpms and it will run well. Any more than that and the feigaos start making alot more heat.