I have a 03 Yz 85, and have recently started racing. However, i feel underpowered by the bikes that have even just a pipe. They seem to be jumping everything a gear lower and still holding the same speed as me in a gear higher. So what im really wondering is If the pipes actually work, and which one is best. I know everyone has there opinions, but can anyone actually tell me where i can find dynos that compare the pipes? I'm stongly looking tward bill's pipe or Pro circuit, however the results they show on the few dynos i've seen are marginal? So if anyone can, give me some info on the pipes, which is best, and if thay are worth the $300 price tag.