Headers & NPP Exhaust
Slightly louder at idle with flaps closed, a lot louder at WOT.
Pro
Joined: May 2007
Posts: 585
Likes: 0
From: Ocean County NJ
I have Kooks headers and Z06 exhaust.
I am not sure how severe the performance difference is open vs closed but I have noticed a slight difference in MPH in my trap speeds. Open being better.
As for sound, closed is tame (like stock) open is LOUD and sounds like a proper muscle car exhaust note.
http://www.youtube.com/user/philithy#p/a - video and sound clip
First 15 seconds, flaps closed; balance open. Crappy recording - still camera doing video - bad microphone, etc. But the car is really clean.............
I am not sure how severe the performance difference is open vs closed but I have noticed a slight difference in MPH in my trap speeds. Open being better.
As for sound, closed is tame (like stock) open is LOUD and sounds like a proper muscle car exhaust note.
http://www.youtube.com/user/philithy#p/a - video and sound clip
First 15 seconds, flaps closed; balance open. Crappy recording - still camera doing video - bad microphone, etc. But the car is really clean.............
Le Mans Master
Joined: Dec 2005
Posts: 6,999
Likes: 1,685
From: Southeast TX
Loud also depends on whether you have cats or not. At idle, mild cam, no cats, and open NPP's it's noticably louder. At WOT, it's way louder. I don't think the performance difference is huge at stock HP levels. As HP levels go up, the spread gets wider. I'm at 672 rwhp and I notice a big difference in HP with the flaps closed. Boost goes up, but power goes way down.
