Originally posted by Davo
i run 65mm on th rear and 61 and i also have another question what sort of motor do the top guns run?
Davo, that's a pretty big split you're running. Why? What pinions and spurs combo do you currently have on the car? If you have 55T, 56T and 57T 2nd gear spurs, you could try pairing them with either 21T, 22T or 23T if you already have them and see which one gives you the best time around the track.
Did you read my reply below to your post earlier?
"I would see what the other cars are running. Check the brand of the car, their gearing, tire diameter and perhaps maybe their pipe and engine. Calculate their tire rollout and compare it with yours. That would be more than close to accurate method.
But I suspect that since most of the guys at your track run Kyoshos and Mugens, you would probably need to back off on the 2nd gear to something like 22/57 or even 21/55 assuming your engine tuning is correct... Just an educated guess...