Idk what's wrong with the LTR's you guys are racing, but my 07' easily walks my buddy's piped and jetted YFZ and my bro's KFX.  All I've done is remove the airbox lid and pea-shooter, and add a bomb.  I'm running 20" rears with the stock gearing too, so I imagine I'd beat em even worse if I dropped a tooth on the front sprocket.

The pipe makes a huge difference! and if you're jetted correctly! but yeah just this last oct. I raced a brand new LTR with a yoshi pipe and pulled 3 bikes by the end of comp hill. I also raced a 09 YFZR and beat him worse than the LTR. At Glamis this last weekend I walked away from 2 450r's and a modded DS650(happened to be my brother) But maybe they didnt have their bikes dialed in very well such as paddles and suspension. The CT sonic pipe for the yfz is CRAZY the power over the GYTR is rediculous!