Grit66

RicK T

2008

crusher1

I bought set of used NPP mufflers and installed them on my 2007

jbripps

Hi - I'm looking to do the same! I have a base C6...they should fit, correct? BTW, if you don't mind disclosing, what did the mufflers run you? You can PM. Also, are they an easy swap?

Thanks,
Jon

Vette_DD

New, as an option from GM, they're $1195.

1pt4brd

buckmeister2

I don't believe GM sells them...it was an option price he quoted. NPP is a system, not just the mufflers. If you install just the mufflers, which is fine, you will always have the baffles open.

A used set will usually run from $200 to $500, depending on how bad the seller wants to get rid of them. They are very stout, and there is little actual "wear" to worry about.

realcanuk

You can find some used ones and get NPP in a box to control them. They are a direct fit.

jbripps

Great, that is what I was looking for, I know GM does not sell them off the shelf. I know the NPP for Z06 has a 3" as opposed to the base 2.5" (I think?). Tough to locate a set. I was under the impression that the baffle valve was in b/w the muffler and tail pipe? If not, I guess mild or wild won't work?
Jon

realcanuk

Your car should be 2.5". I'm sure you can buy the muffles from GM if you want new ones. I did for my 07 but it was a long time ago and I forget the price. The valve is part of the muffler, but you need the NPP in a box to control the valves. The M2W is just a switch for a car that has the factory vacuum system.

https://www.nakidparts.com/c6-corvet...etrofit-system

Moman01

buckmeister2

The valve/baffle is located just outside the muff, in the section of tailpipe before the chrome tips. When you look at a set, you can see the valve, pivot arm, and vacuum diaphragm mounted just outside the muff. If you get a same-year 3" system off a Z06, it will fit, but you will need reducers to go from 3" to 2.5". If you have an auto tranny, you would also need to first remove about 5" from the left over-the-axle pipe in order to slip the pipe past the tranny shift lever, into it's correct place, where you could then use the reducer on that side to bridge the gap. It will be easier with a similar-year 2.5" set. It is often just as easy to find the muffs and h-pipe in the same sale. If someone replaced their 2.5" system with headers or a full Z06 system, they have the correct h-pipe for the muffs.

bobeyoung

I found the NPP system for a 2008 base on eBay for my 2007 base. Very easy to hook up. I think I paid 4 or 5 hundred dollars.

jbripps

Wow - this is more complicated than I thought. I have a base 06A....so I would need the non Z06, and base NPP mufflers, but not from an 08....sound right? Really appreciate the education, I did not see any prior threads with this much depth.

Jon

TorchRedFred

I have the NPP dual exhaust, but it's more like a single exhaust mode since I keep them open 99% of the time. And the sound of the open NPP exhaust is OK but still not great. If I had a car with the standard exhaust, I would probably look at going with an aftermarket exhaust instead. Even with my NPP exhaust, I am sometimes tempted to go with a Corsa or some other aftermarket exhaust.

bobeyoung

Pretty sure you'd be ok with base 08 setup. It won't work with 09 and newer on your 06.

Moman01

jbripps

Thank you! Do I need the NPP in a box for 09-13 as well? Not sure what the difference is. How is the sound difference with the mufflers only? Not sure the other pipes are any different (cat back, etc.)

Jon

HOXXOH

This is possibly the most talked about mod on the forum, so if you have a full day to spare then type "NPP" in the search box and enjoy. BTW, just to let you know NPP is an option code, not the name of a muffler, for the entire system that was available from '08 to '13 on base cars and '11 to '13 on Grand Sports. Although the Z06 had a similar system, it was standard and not an option. The muffler itself is not called NPP, but uninformed people think so. There are several ways to make things fit and get similar results, depending on the donor car and the owner car. Different years and models had the bi-mode mufflers, but the only one that is a direct bolton for your base '06 is from an '08. It'll help understand things a little better if you look under your car and someone with bi-mode mufflers. The term NPP-in-a-box is the system that controls the valves to be open or closed on a non-original bi-mode system. There are other controllers and some people made their own, but they're less popular.

BTW, fill out more than just "male" on your profile, so people know what you're driving and where you are from. It avoids the 20 questions game.