Currently the bike has all the "free mods", pro moto exhaust endcap for the stock can and is jetted cleanly with a JD jet kit. It runs great but still seems a little choked up compared to my WR 426 with a YZ exhaust. I know that once I installed the YZ system on the 426 and dialed in the jetting it ripped!! Very responsive and fun to ride especially in the whoops or anywhere you needed to be able to loft the front wheel. The 450 on the other hand is a little more "mellow" and doesn't have quite the hit but hopefully I can change that!! My riding consists of mostly desert with some trail riding in the mix. I would like a little more response a maybe more midrange along with a nice throaty tone without being too obnoxious.
I thought about going with the YZ exhaust for the 450 but it gets expensive once you factor in the end cap too. For that reason I would like to go with a full aftermarket system and have narrowd my choices to the Dr. D, Yoshimura RS-2 and FMF Power Core or Q4 with the Power Bomb head pipe. These can all be found in the range of $400-$500 if you look around although the DR D. seems to be a little over $500. From my research they all seem to be well made and provide a nice sound with some performance gains. I have seen and heard both FMF systems on '07+ WR's as well ast the Dr. D. I have not seen the Yoshi in person but have seen pictures of it mounted and heard it on some You Tube videos and I was impressed. My only concern with the Dr. D is that the header seems to block the oil filter access and needs to be loosend for oil changes. This isn't a deal breaker but it is an inconvenience that I am aware of. So what are your oppinions and experience with these exhaust systems on the WR? Looking forward to the responses.
Edited by dustdogg, August 30, 2012 - 04:51 PM.