I finished a new short exhaust and muffler 2 1/2 free flow on my bike. My old system had two reduction diameter bent in the center section and my yoshimura had 2 1/2 in and 2 out. That create restriction and i lost power. You can see in my video 11psi. I don't run with the new short exhaust, because i don't have finish all uprade projects on my bike. Coming soon.