sellshort

2012 TR GS. F____ in A

Rob 99

You can purchase it from and have it installed by a Chevy dealer or your own shop can install, also you can find them for sale here on the forum or ebay as well as wrecking yards, you will need the aftemarket
'mild to wild' switch to operate sold here on the forum, good luck

CO Lightfoot

The NPP dual-mode exhaust is a factory option beginning with the '08 C6 coupe. (It is standard equipment on the C6 Z06.)

NPP is not a GM aftermarket option.

Google "NPP in a Box" if you want an aftermarket NPP-type system for your C6.

Or you might get lucky and score a system like this:

http://forums.corvetteforum.com/c6-c...tte-pic-3.html

AtHomeSoda

The Z06 does not have NPP...It has Bi-Mode.. The NPP has a straight pipe on the inside of the muffler... so when it is open it sounds great. The Bi-Mode has a perferated pipe, and is not as loud.... Big differance.

CO Lightfoot

Thanks for the correction.

I thought maybe there was a difference, just couldn't remember what. (And too lazy to research it.)

z51vett

That changed for 2011 and for 2012 all vetts got 4 catalyic converters.
z51vett

BWF07

The NPP in a Box, is just the controls for the system, you will still need the mufflers that have the straight pipe and valve. I wonder what they cost?

z51vett

Mufflers are around 1500 new at dealer.Used around 6 to 800 I think.
z51vett

sellshort

So if I don't have the switches I don't have npp? Sorry I'm so lame, I just don't understand if I have it or not. I have read alot about pulling the fuse to keep it open but if I don't have it it wouldn't matter,right? 2012 TR GS. Any clearity about if I have it or if I can get it would be greatly appriciated. Bill in San Diego

See5see6

If your tailpipes look like the picture in post #3 you have NPP. If not......then "nope" you don't. The valves and actuator arms are the clue.

BWF07

As stated, look at the exhaust and see if you have the valves, also if you have run the car hard, they would have opened and you would have heard them open.

sellshort

Ok. No valves. I guess I don't have it. The car still roars when the rpms are around 2500 between 1st and 2nd or 2nd to 3rd. Pretty quiet in 4th. Why is that if I don't have the special exhaust?

BWF07

You have a few options, one buy a set of the NPP mufflers and the kit, or buy and after market cat back system, sounds like the cost of a new set of the NPP and kit will run about the same as any of the good aftermarket systems. The difference is with the NPP you can have it both ways nice and loud when you get on it and stock sounding under normal driving, whereas the aftermarket system is rumbling all the time, but at a different level then the NPP.

You can also do the muffler mod that seems to be going around and it cost little to nothing except your time.

CO Lightfoot

For a given speed, the rpms are lower in 4th than lower gears.

Also keep in mind that wind/tire/road noise at higher speeds in 4th will mask the exhaust sound.

So of course the exhaust seems quieter at 2500 rpm in 4th (~57 mph) compared to 2500 rpm in, say, 2nd (~32 mph).

Tip: Take a look at the sticker in your glovebox. It lists features/options codes... if it lists "NPP", then your C6 originally had NPP from the factory.

I know it's a longshot, but that's what happened to trenchgun:
http://forums.corvetteforum.com/c6-c...tte-pic-3.html

Flh Den

Obviously it was not ordered on that car.

TLS_Addict

He was asking why his car was loud. Not why doesnt his car have the NPP.

Flh Den

OOPS sorry, misread the post

TLS_Addict

Its ok, us folk up north have issues in the winter. Combination of lack of sunshine, cold weather and not driving our Corvettes. lol

Flh Den

I know Cabin fever already and it isn't even winter yet

TLS_Addict

No joke.....I was looking at the garage last night thinking about how much fun I could be having down south.