4s vs 5s and gearing

[tc3_racer_001]

any way tat you could run a slightly bigger spur?

hv is only good when your aiming for the same speed. a 6s which goes 35-30mph will be much more efficient than a 3s which does the same speed... id suggest trying without brakes, adding a smaller pinion and go from there... easier and much cheaper than putting more money down for a motor which may not be warrented (if you do change the motor, your 4s pack will be slower, whereas if you keep the same motor its as easy as changing out the pinion beofer your next race!!

this make sense?