but it is also louder. In this particular test max power dropped from about 614 hp to 600 hp. Coincidentally my Z makes 600whp on race gas. However driving on the road at 2500 rpm under load (up a grade) the sound level is just too much to enjoy for a regularly driven car (for me at least). I just swapped 3" full SZ exhaust for their 3" to 2.5" test pipes paired with a B&B 2.5" cat back. I haven't driven it yet to see the difference, but I am hoping it will reduce the dB level from >100 something <100....