I just ordered a Steeda cat-back exhaust today from American Muscle all stainless 2.5" with 3.5" tail pipes. I have stock H pipe what is the typical rear wheel HP gains? Has anyone ever dynoed just a cat-back mod before. I am thinking 7-8 RWHP.

I can't wait until install this exhaust.

 

maybe like 1-3 hp at the crank


to do anything really significant you have to get rid of your cats and work from there

 

Good choice on the catback... your gonna like the sound of it. For the GT's, its not gonna give you a big performance gain... but it'll make ur car sound much better. Also, think about getting midpipe to go with it sometime... it will really wake up your cars exhaust note.