Exhaust mode
Race Director
Joined: Jul 2007
Posts: 10,961
Likes: 2,643
From: Texas Hill Country
the middle pipes move quiet exhaust.
the butterflys on the outer pipes open up to free up flow for more noise and 5 HP.
I'm Batman..
Joined: Apr 2014
Posts: 6,142
Likes: 921
From: Lehigh Acres FL
Tech Contributor
Safety Car
Joined: Dec 2012
Posts: 3,841
Likes: 1,856
From: St. Louis Metro East IL
NPP info links
Check these links for an NPP schematic and more info / options:
https://www.corvetteforum.com/forums...ust-issue.html
https://www.corvetteforum.com/forums...ck-result.html
Also search for NPP. There are lots of threads and lots of confusion.
https://www.corvetteforum.com/forums...ust-issue.html
https://www.corvetteforum.com/forums...ck-result.html
Also search for NPP. There are lots of threads and lots of confusion.
Instructor
Joined: Dec 2009
Posts: 239
Likes: 5
They have integrated sound control valves in the exhaust system just ahead of the mufflers on each side. They are supposed to modulate the sound in four cylinder mode to make it more pleasing to the ear. How affective they will be is probably subjective, and will cause more controversy on the forums.
These are not to be confused with the valves in the muffler outlets that come with the dual mode NPP exhaust option. With NPP you will actually have four valves; two before the mufflers and two after the mufflers. All are now electric as opposed to the vacuum operated valves used with the previous NPP option.
The two valves before the mufflers are to make a more appealing noise (sounds like a M model Farmall tractor) in 4v mode and they are there with or without NPP.
Read more: http://gmauthority.com/blog/topic/c7...#ixzz3DaothCyS
These are not to be confused with the valves in the muffler outlets that come with the dual mode NPP exhaust option. With NPP you will actually have four valves; two before the mufflers and two after the mufflers. All are now electric as opposed to the vacuum operated valves used with the previous NPP option.
The two valves before the mufflers are to make a more appealing noise (sounds like a M model Farmall tractor) in 4v mode and they are there with or without NPP.
Read more: http://gmauthority.com/blog/topic/c7...#ixzz3DaothCyS
