Originally Posted by ph0rk
The 2011+ camhead bikes have a valve that opens in the exhaust manifold at WOT. I couldn't get a good listen because its hard to stay at WOT for long in the city and be legal
Wunderlich makes a part to facilitate removal of the flapper
. I've thought of doing it to mine, but also kind of don't care. The bike sounds pretty good when it's in the higher RPMs, and at low RPMs I'm not real interested in being real loud anyway. The valve and wiring are ugly, though - my friend's bike (earlier) doesn't have it and looks much cleaner back there. His Leo Vince pipe sounds a bit better, too.