06 C6 vert

I want to do the NPP but am concerned about the quality of the sound of the NPP when its closed. Is the closed sound pretty lousy? , as good as stock non NPP car?

Any thoughts on this?

boraxman

Closed is quiet for the most part until it opens at ~3500 rpm

* I guess I should add that I havent experienced a stock non-NPP system for any sort of comparing.

FloydSummerOf68

I have NEVER heard someone utter "as good as" when talking about stock base C6 muffler sound.

There is no car that sounds more anemic than a stock C6 with base mufflers...

Nothing you could possibly do would be worse

Top_Fuel

No need to be concerned. Pick up a pair of adjustable NPP collars and set the level of sound you prefer when the valves are closed.

Don-Vette

What Floyd said.

AORoads

I completely agree, and have what Top describes above.

My take on it from memory is that the base exhaust system w/o NPP is quiet. My car w. NPP but without the collars, is quiet but just a tad louder than non-NPP equipped Corvettes. However, with the collars, I've adjusted them to where I find it perfect at all times, and so do my neighbors who know that mine is not "the noisy Corvette". Really.

(because there is one in my development that IS "the noisy Corvette" and his neighbors really don't like him...."

brooklync5

I added it to my 06 along with the mild to wild switch. When it is closed it is pretty quiet and doesn't sound like much of anything. Open however I find it to sound just as good as any other after market "loud" exhaust out there. The mild to wild switch is great for when you want a break from the noise or when you feel like hearing all the noise your car can offer. This is my 3rd exhaust on this one vehicle and certainly is the best I've had so far. I don't think I'll be changing it again.

06 C6 vert

Thnx for the input,

Yes I did a swap from my stock into the Bassani system. The sound on it was incredible at revs and idle, but the drone killed me on my DD to work. I then swapped back into stock.

The Bassani had a huge Euro sound, very loud but a great tone to it.
didn't bark like a F car but more like a Austin Martin.

Thrash

When the NPP is closed it sounds like a Cadillac, and I love switching to that when appropriate ...

brooklync5

No problem. That's another thing about the npp system, even when open there I no drone!!!

CasualGuy

Get the NPP. You'll love it. I don't have M2W, which as I see it is just a good excuse to keep the revs up.

Every time those butterfly valves open up I can't help but grin from ear to ear!

vettenevodrvr

I had an '06 with base exhaust = quiet unless you really nail it. Not nearly as loud as the NPP with open valves.

I have a '10 with NPP and Mild to Wild = quiet when you want and loud when you want. NPP with open valves is a straight through muffler. Whenever I go into a tunnel, I open the valves, roll down the windows, and floor it. Music to my ears!!! Probably aggravates other drivers, but who cares.

With the valves open, you'll get some drone here and there, but not at cruising revs. NPP with a controller is one of, if not the best, exhaust for the 'Vette.

ontcanuck

Have a GS convertible with NPP option and mild and wild remote. Great sound,nice rumble at idle love it. Main fault is with the top up at cruising speed has a bad drone so thats were the remote comes in handy. The corsa extreme has a better sound all around and no drone best exhaust on the market IMO

dvilin

Fineride

I went from an 08 A6 NPP to 09 Z51 M6 standard exhaust. The NPP was considerably quieter in closed mode than the non NPP and did sound lousy especially at idle. I never tried the partial open so can't comment on that but that might be the way to go. With an A6 it was too loud to leave open all the time by pulling fuse. With the 09 non NPP, I actually like how it sounds enough to leave it stock. Having the M6 might make a difference as the engine probably revs more just driving around so I hear more engine/exhaust noises than with the Auto. Very pleased.

coolcat

The exhaust note with the flaps closed is embarrassingly quiet.
Sounds like a Chevy Malibu.

Your better off just pulling the fuse and listening to "The Sound of God"
roaring through your exhaust outlets.

RDKING

Awesome

Malco

I just changed from standard to NPP mufflers on my 2007 Coupe. The NPP in the closed position is slightly louder than standard. Open they are like having no mufflers at all.
On the whole I am glad I made the change.
You will need the NPP control kit. I have the NPP in a box.

laconiajack

This is definately the way to go. For an initial setting you might adjust the collars so that the valves are held open about 1/4 inch instead of closing all the way. This gives you a nice exhaust note with no drone, plus some burbelling and popping when backing down through the gears, yet won't make you an inconsiderate neighbor like those that simply simply pull the fuze.

j_digi454

Same for my 07. It is a little louder now with the valves closed since I added ARHeaders and Hi-Flow Cats.