I just got a Raptor for my wife. (ok-me too).. The new limited, which I get in March, so in the intrum, I've been reading about upgrades. IN Dirt World there is a great Muffler shootout for the Raptor. There were 12 mufflers and it included dyno's, noise level, weight, price, etc. I was a great artical if your looking to get more HP. The winner added 13HP to the 660 engine. WOW. 35.? stock to 48.? with the CT Muffler kit which include a new needle and K & N filter setup. all for about 600.00. What inpressed me the most was the smooth Dyno results. Great increase all the way around. Has anyone seen a similar artical for the WR426. I want to get more power for my WR, but no one seems to give difinitive HP increases with dyno and noise info. Whats the best muffler out there.