K&N will best be served along with exhaust and rejetting.

 

I went BLACK need to be as STEALTH as possible!

 

Two things I learned while racing cars and boats. First was that seat of the pants feel can lie to you big time. Trust either a stop watch, the change on the speedo or a time and speed slip at the race track. Second was one mod at a time, always. Why one at a time? Well the best example I can think of is I once changed the prop, engine height and did some changes to the bottom, all at the same time. Boat slowed down 2 mph. So I put the prop on the shelf in the shop, lowered the engine and changed the bottom back. Then a guy that has forgotten more about race boats than I will ever know, says after watching me race, was to try a prop, the same one on my shelf and to raise the engine 5/8". I told him I had tried it and it didn't work. Ron says, "What else did you do?" I told him and he tells me the prop will work and I need to raise the engine to make it work better. He told me "One at a time and see. Prop was good for 3 mph and raising the engine was good for 3 more. So the bottom change was worth a minus 8 mph. That year I set 3 speed records and also took the National High Point Championship. So one change at a time.

Chumley is probably right, a better airfilter and exhaust almost always require a rejet to optumize their worth.

 

I just ordered a hmf pipe from an ac dealer in mt. vernon indiana. He told me that the 659 v2's run rich from the factory that you don't have to re-jet. If you only add more air and not fuel how do you get more power?

 

If you start out rich you will, as long as you don't go to far. If you get the engine to lean you will melt a piston and then it gets real expensive real fast. You need to learn to "Read" your spark plugs. How they look tells you if the engine is lean, rich or right in the middle (usually about 14 to 1 air to fuel ratio for max power). Most manufactures of pipes, air filters, ect. will have recommndations on whether to rejet or not. It is always a bad assumption (regardless of what your dealer said) to assume you are rich now without checking first.