I have t5 pipes, rad valves, k&n filter, cool head on 93oc, +4 timing plate, moddded shift star, hinson basket, and the real mod, a port job from Kevin herr. I'm able to smoke my buddy who's 40lbs less, more talented, and on a built yfz450. the only times he wins is if I hit neutral and the best he Does is a tie otherwise. This buddy of mine is fast and consistant. I say you need intakes, cool head, and porting combined with good rear tires. My buddy asked a guy who's a well known local bike builder if he could adjust his valves and he said he doesn't work on 4strokes they're for fags!