Yea, I'd like to know as well. I don't need to know for fan purposes, but to power some LED's. LOL.

For drifting, optimal gear ratios differ depending on what motor you're running. It's safe to say that you can use a 6.5:1 final drive ratio for both 27T stock and 19T spec motors. For brushless, you want a 7.5:1 final drive ratio. That way, you'll get cooler temps and longer runtime.