Originally Posted by KC10Chief

Personally, I'd stick with a 48 pitch for durability. If you're new, you're not going to be able to tell enough difference to fine tune your gear ratio. A 3.8 is going to give you more top end speed and less acceleration. A 4.0 is going to give you more torque to accelerate with but less top end speed. It all depends on your track too. If you have a lot of high speed straights, then maybe the 3.8 would be better. But if there's a lot of hairpin turns or corners where you really have to slow down, then the 4.0 might be better for accelerating out of them. The races aren't usually won on the straight aways anyways. For most situations, I'd say that a 4.00 gear ratio would be a great place to start. Pinions are cheap and easily changed on this car. I'm totally speculating here, but I'm thinking that a 4.00 gear ratio will let your motor run a bit cooler than a 3.80 would.