Saturday, after I re jetted my raptor I was out testing it and I raced a kid on an 03 piped and jetted 400ex. I am running an HMF and a K&N air filter kit with my lid removed, plus a dyno jet kit. Anyway, we raced about 5 races down the road that were about 100 yards. And 1 race that was prolly closer to 300 yards. I beat the kid 4 times on the short races and I'm not counting the 2 races that he gave up on because he hit dirt on the road and spun his tires :. The longer race, he pulled ahead right around the end of 4th and after that I was owned. I was really impressed at how much power gain I got out of these mods and I'm not even through jetting it. I can't wait to really get some good stuff for the engine so I can smoke any 400 out there, ;D LOL!