D&D Power Y-Pipes are the biggest HP gain for the $ of any aftermarket product available. Just bolt on and feel the Power. We have seen gains of more than 12 hp on the 1000cc motors. NEW for 2010 CFR & M 800 HO motors pulled a 7 HP gain from independent dyno test at dynotechresearch.com. Check with your local ordinances about local laws concerning exhaust modifications.