I just git rid of my stock pipes and got a K & N filter and Vance and Hines pipes. Also, I had a ThunderMax installed. WOW- I´m not sure which of these additions did the trick but my bike rides and sounds AWESOME. Now I need to get my handlebars closer to me to stop the back pain. Any suggestions? I´d like to keep my own stock pullback riser for sure. Anyone change out their bars?