I have a 2003 Wr450 with all free mods done and was looking into buying an aftermarket exhaust. I've been reading posts on the forum and am having a hard time choosing between the FMF TI powercore and the Powercore4 with Qinsert... I mostly ride Long straight fireroads with some ocasional woods. Which exhaust produces more power and do you guys think would work better? Any help would be greatly appreciated .!!