Just put on a Dynomax Super Turbo with 2.75 pipes from the cat to the muffler. I already reset the PCM. How many miles do you have to wait before you start to see the gains of a new exhaust system?

 

Theoretically you ought to notice them inmmediately. The thing is, you probalby gained less than 10hp from the exhaust if i had to venture a guess. Thats a hard amount to "feel".

When I did my exhaust, I noticed how it took less pedal to get the car moving and to maintain certain speeds. Thats probably what you'll notice, not really a push back in the seat.

 

Any gains should be noticeable right after the instal. The only change you may notice, which varies, is the sound level. It took my exhasut a good 8,000 miles before it got noticeably louder.

 

Does it really get a lot louder? Why is that? I figured it would just get lower in pitch.

 

Many mufflers like the Dynomax have a fiberglass packing inside which helps deaden the sound. When you first get the exhaust, the packing is loose and as you drive the car it heats up, melts some and other bits of "blow out" in turn making a deaper sound.