2 things that you can do that are fairly cheap that will boost your performance are 1) take the baffle out of the stock muffler or 2) buy a Tower 46 muffler.

I took the baffle out of my 46fx on my UltraStick and it added about 1000 rpm and that sucker screams along now. It's a little louder, but still quieter than my Pitts muffler on my Bipe.