J&P Community

 I am changing exhaust, air cleaner, and adding a power commander to my bike. Although I"m sure these changes will increase performance, am I kinda of spinning my wheels by not making other changes? Increased flow thru air cleaner - is that restricted by throttle body? Are there severral things that need changed to reach an appreciable increase of horsepower? Injectors - etc.?

The biggest performance gains you will experiance will be from the aircleaner and exhaust upgrade. The reason for this is the hoops Harley has to jump through for the EPA. A 15-20% increase is what you will see over stock (remember a stock unit produces in the neighborhood of 65 HP).  Making another gain of the same size gets expensive.  The Injector body is not that restrictive untill you try to achive over 100 HP.