Exhausts/mufflers are only good for getting the sound you want & do almost nothing for WHP. If you are looking for power outside of a tune add downpipes but again a dealer will not be happy with you. Downpipes are most effective if you have a tune.
Best bang for the buck ($500) is the JB4 piggy back tune. Cobb is also a good tune, but more expensive.
My car with only a JB4 & FMIC about $1100 does 12.5 X 114.5
Vbox is from a FBO JB4 car that runs 11.1 X 130 at the track.
Last edited by bear-avhistory; 12-25-2012 at 10:44 AM.