I went from a 13t up to thrying a 14 and 15 t because I was running at very high rpms on the track. I did take the pinion off and the buggy rolls great! no binding. As far as the longest straight, We don't currently have a long straight. We have a large sweeping corner which I do not max out on. I went out and got a temp gun. I will be at the track thursday or friday, i will get some temps on motor after 10-12 mins or running.