Im a newb and I understand a little about gearing.
Larger pinion, faster the car. Smaller pinion, slower the car.
Larger Spur gear, SLOWER the car. Smaller the spur gear, FASTER the car.
I do not completely understand ratios though. I have two cars and would like to find an ideal gearing for each. I do not have a temp sensor to experiment.
I have a TC4 with a mamba max 7700. I just run it in big parking lots and like it to go fast. I dont need to push it to the extreme though. I want a gearing thats quick but safe for the motor.
I have a TT01 with a mamba max 5700 and I use it for drifting only. It has drift tires and all alum. and titanium upgrades.
I just run 6 cell nimh packs in both.