Ive seen a few posts on here about how bad the FMF pipes are, one even said he lost power with a FMF. Then I see the complete opposite, I see the FMF 4.1 rct holding its own with yosh and lsr. So if people could post up dyno charts with before and after or at least say what stock made on that dyno that would be awesome since dynos vary. I have a hard time believing FMF is that bad. I made just shy of 60hp with a FMF on my crf450 that I built. I know I could gain more up top with a different pipe but good power nonetheless.