Vetteinplano

What are the differences between the ZR1, Z06 and NPP mufflers?

RicK T

Not sure what you're asking but very generally, they differ in their internal design. Each one is tuned to the specific engine. The NPP (only a GM option code, doesn't mean anything) comes on '08+ LS3 cars. It is the loudest, harshest sounding because the straight pipe side is solid in the muffler, basically mimics an exhaust cutout. The Z06 and ZR1 mufflers straight pipe inside the mufflers is perforated so the sound is lower and mellower than the NPP's.


Base muffler pic:




Z06 muffler pic:





I haven't found any pics of NPP's inside but they basically are the same as Z06 but with a solid pipe instead of the perforated.


And here's a slide from the 2007 C5/C6 Bash at the Museum where GM introduced the NPP system:

haljensen

All three have 2.5" muffler inlets but the C6 NPP is the only one that has 2.5" piping to the muffler. The Z06 and ZR1 both use 3.0" pipe.

'08 NPP will bolt into any '05 to '08 C6 without cutting or welding.

'09 and up NPP will bolt into any '09 and up C6 without cutting or welding.

Z06 and ZR1 axlebacks will not bolt into any C6, the pipes must be cut and welded to make them fit.

Skech137

I have a 06' A6 C6 and want to put a NPP setup on it. I was wondering what would be the best way to go. Should I use a 08' NPP or make a Z06 setup fit my car?? Also, what do you guys think would have the best sound with my A6 trans and LS2 engine??
Thanks in advance for the help! Steve

FNBADAZ06

Actually, the NPP and the ZR1 mufflers have the same interior construction.....baffled "quite pipe" and straight pipe for the loud side.

The Z06 mufflers have the baffling on the "loud side" and straight pipe on the "quite side". The "muffler mod" performed on a Z06 muffler closes up the baffles and turn it into a ZR1/NPP muffler on the loud side.

Vetteinplano

Sorry, purpose of the question was to determine if the ZR1 muffler is just a "corvette-taxed" muffler of similar design to either the LS7 or LS3 bi-modal mufflers.

I've seen some ZR1 mufflers advertised for in excess of $1,000 and LS3/Z06 versions in the $500 range.

Now I know.

Thanks for the information!

FNBADAZ06

You're somewhat correct with the vette tax comment.

I have ZR1 mufflers on my Z06 and the benifit are two fold:

1) with the valves closed, my Z06 is QUITER than a factory Z06 because of the baffled "quite side" pipe.

2) with the valves open, my Z06 is LOUDER than a pre-2010 Z06 because of the straight "loud side" pipe.

The ZR1 and Z06 pipes are direct bolt-ons for either car as the over axle pipe is 3"....where the NPP mufflers are a 2.5" over axle pipe. To put either Z06 or ZR1 mufflers on an LS3 car requires adapters or a full 3" exhaust system.

CBvette55

Will a z06 cutback fit on a 2008 base model with an aftermarket headers and xpipe.

FNBADAZ06

If the mid pipe (x or h) is 3" outlet , no problem...if it's a M6 car.
I believe the over axle pipe needs to be slightly modified if you're are installing on an A6 car.

CBvette55

Sweet I have a mn6 car.

0Anthony @ LGMotorsports

Z06- 3" over the axle pipe, very muffled, quite quiet.
Zr1- same external dimension as the Z06, 3" over the axle pipe, however, has the "muffler mod" already done, its quite loud when the flaps open.
Z51/NPP- 2.5" over the axle, similar muffler construction as the Zr1, but we have not cut a Zr1 apart yet.

Z06 mufflers will fit any corvette with the right header system, or Z06 exhaust. A6 cars will require lots of modifications to get around the transmission. Its very tight.

Vetteinplano

Thanks Anthony, you guys did the Z06 manifold/converter/H-pipe mod on my car! Appreciate the information!

Dragon777

Hi guys,

has anybody fitted an exhaust from ZR1 on a regular LS3 C6 from 2009?
Are there supposed to be any problems? And how will the ZR1 exhaust sound on the base C6?

Thanks
D

08velocity

ok so I have an 08 c6/a6 I pulled the fuse and while it is a bit louder, I would not say its" wow thats loud !" I've asked this before but do you think if I were to do the" stock muffler mod " to my npp mufflers it would make it noticably louder/deeper tone ?

Cuthroat

I know this is an older thread, Hope Rick T see's it. I'm not sure i'm understanding this. If the newer bi-modal exhaust has a solid straight pipe instead of perforated, how does the exhaust get to the fiberglass packing and flow out the other pipe when the butterfly is closed? I see no area that is not sealed off from the valved pipe in the pic you posted. Really curious how the newer design works. Thx

Cuthroat

Bump for Rick