This thing is no where near the cutting edge of what a V-Twin is capable of. Its a gimped engine to keep from running away from the drivetrain components.
Plus, some people love modifying cars and realize that when you increase one aspect, you have to continue to increase other aspects to keep up.
If it were me and I was trying to increase performance on a M3W, the first thing I would try to do after addressing the poor exhaust would be to add lightness.
