Quote Originally Posted by WickedGoat View Post
Anyone care to explain why a tune is not necessary? I put SLP long tubes on my GTO along with a cold air kit and had it dyno tuned afterwards. The car was loud before the tune... After 6 pulls and a drive with the lap top hooked up, it was more quiet and I gained about 20 HP. The tune helped lean the fuel mixture across the RPM band and tied all of the mods together to get the most out of them. I would assume that a GTP with headers or some other manifold mod, air filter replacement, and down pipe replacement would benefit from a tune of some sort, similar to any other car. Maybe a tune is not required, but very beneficial?
I agree with your principal statement: that tuning could be beneficial after headers/exhaust work. But unless you already have access to tuning software (ie.already own hp tuners or dhp) I wouldn't pay for a tune for just exhaust work and a Cai or Hai. Once you drop pulleys then definitely. But how much is a dyno tune? 500? Overkill pcm is 200 minimum still. Not worth it for just flow mods.

Drop pulleys, then tune at the same time. If your not doing that then roll as is.