im getting my raptor bored 30 or 40 over right now 11.5 to 1 piston and im gonna get a new pipe cause this W/B R-4 pipe is only a slip on and its not enough power and i just want more power out of my raptor i cant decide weather i should get a FMF Titanium 4 14" can with mid pipe and powerbomb header,, Yoshimura full system,, or the White Brothers E series please email me at RedneckMXrider2@aol.com with ur reply because my computer is messing up thank you