Originally Posted by Rapid Dog
True dat, but with a caveat.
Changing the muffler only does next to nil. Changing the headers to eleiminate the cat converter opens the system up to help it 'breath', causing less back pressure, and in turn, allowing the boxer motor to rev and de-rev easier.
The result is less restriction and a smoother running motorall around.
Money better spent on a set of headers than a slip-on can.
I guess it all depends on your level of connection to the bike. The numbers move up and down the scale, but do not significantly change with even a full exhaust. Smoothness? I believe you would get more from a fuel enricher.