Originally Posted by Duc_Z09

He's telling you to go steeper with the driveshaft/wheel rotation ratio. It's like choosing a lower gear on a bicycle... you can accelerate faster at the expense of some top end speed.

Longer explanation: When you divide the number of teeth in your ring gear (the one that turns your rear wheels) by the number of teeth in your pinion gear (the one attached to the driveshaft that comes directly from the transmission) you get a number like 2.73, 3.69, 3.73, 4.10, etc... What that means is that the driveshaft makes 2.73, 3.69, 3.73, or 4.10 full rotations per full rotation of your rear wheels. The higher the number, the more power per rotation you're going to get. But the tradeoff is that your gears will red-line a lot faster (you'll have to shift sooner) and your top speed will take a hit (if you care about 150+ mph). You'll also be running at higher RPM per any given speed in a given gear, so fuel economy will suffer too. With a 6-speed you'll probably just end up running 1 gear higher than you were previously though.

Originally Posted by johnwiki

I did 4.08 and its a decent mod, good amount of acceleration increase. But you will cruise at higher revs. At 70 im at about 3000.