Dual-mode exhaust must rarely be ordered

[Camaro_Corvette]

Originally Posted by cornerspeed92

If its just a gimmick,then whats the reason our "STOCK" 1LE's are putting done 400+ at the rear wheels? and it sounds bitchen!!!!!!!!!!

Who dat?

EDIT: nevermind, found it myself. Damn

[natmad]

For $895, select Camaros can be equipped from the factory with an exhaust system that not only sounds fantastic (see video above if you don't already drive one so equipped) but also allows for noticeably quieter cruising with no droning. You get the best of both worlds. Quite an amazing gimmick.

Now, let's modify a dual mode exhaust Camaro with long tube headers, high flow cats, an intake and a tune. We still have an exhaust system that sounds fantastic and is noticeably quieter at cruise. Did I say that already? When modified, the NPP exhaust option is probably going to sound louder with a lower tone without being too loud. Nice. I will not buy a Camaro without it. Nor will I buy a Camaro without the 1LE package either, but that's another story.

Dissing the NPP makes no sense other than what Aesop's sour grape's fable can explain. Think about that with a glass of Woodford's Reserve.

[gajagfan]

Originally Posted by Camaro_Corvette

Everything I've ever read says this exhaust will give you a HP gain.

It does not. The restrictions of the exhaust system are up stream of the mufflers, which is where the NPP happens. Please show me one piece of GM literature that shows that the NPP adds power to a Camaro. I do not think you will find one.

[Norm Peterson]

Originally Posted by natmad

For $895, select Camaros can be equipped from the factory with an exhaust system that not only sounds fantastic (see video above if you don't already drive one so equipped) but also allows for noticeably quieter cruising with no droning. You get the best of both worlds. Quite an amazing gimmick.

I'd listen to it if I knew which of several videos coming up on that link was intended and if my computer would play it (it won't).

I suppose that if "the sound" is all that important to anybody, then it's a good thing for them. But it's not dissing the NPP for anybody else to imply that it isn't for them.

I happen to like my cars to eventually have some "voice". But not badly enough to ever mod an exhaust system right away, and never to be so much louder that I'd want to be able to tone it down at times. Something with reasonably low restriction that falls somewhere in the middle all of the time works for me. For me, $900 would be better spent toward seasonal tires, or the wheels to put them on, or on a few track days beating up on them.


Norm

[natmad]

It is certainly reasonable to believe that reducing the backpressure in the exhaust under load via the NPP bypass sysem can result in a small gain in power over the standard exhaust with all other things being equal. The Corvette demonstrates this effect with published horspower figures.

It is also reasonable to consider that Chevy chose not to publish a similar increase in power for the Camaro due to certification and testing costs or maybe they just didn't want to stir the Camaro fanbase pot. Also, the electronic power steering system probably frees up a little power without a certified published increase figure.

Perhaps these two real possibilities can explain slightly higher wheel horsepower numbers found by some forum members here with cars thus equipped. If an aftermarket cat back can free up just a little power, why not the NPP? Thinking about that over a bowl of Cheerios.

[davidcroft]

Originally Posted by S3XPanther

Video please.

http://www.camaro5.com/forums/showth...=274776&page=2

click on the blurry picture of the car on the dyno. Only vid I have of the car....crappy I-phone vid at that

[Chi-One]

Originally Posted by mhoskins76

You sure about that? Tried building one on the GM.ca website and you can't get the NPP with an auto. The NPP is only available with a V8 and the 6-speed manual.

I have it on a 2LT with auto.

[Rocky1974]

I hate it!.............Because I don't have it..............

[Rocky1974]

Originally Posted by gajagfan

It does not. The restrictions of the exhaust system are up stream of the mufflers, which is where the NPP happens. Please show me one piece of GM literature that shows that the NPP adds power to a Camaro. I do not think you will find one.

I don't know whither it does or not, but the same option gives the Corvette an extra 6 horsepower, so I believe it "could". The fact that you can't find any literature supporting a horsepower gain, may have more to do with internal GM politics than actual horsepower gains. GM always keeps the horsepower ratings lower on the Camaro vs the Corvette, even when they have the same exact hardware. They always blame it on inferior Camaro exhaust systems, which may be true, but I have my doubts.

[dave eckhardt]

I have a 2013 2 LT conv.automatic coming with dual mode exhaust.my understanding is you can't order a SS that has dual mode exhaust and automatic.might have something to do with active fuel management system.someone in the know please respond.

[Norm Peterson]

Originally Posted by Rocky1974

I don't know whither it does or not, but the same option gives the Corvette an extra 6 horsepower, so I believe it "could". The fact that you can't find any literature supporting a horsepower gain, may have more to do with internal GM politics than actual horsepower gains. GM always keeps the horsepower ratings lower on the Camaro vs the Corvette, even when they have the same exact hardware. They always blame it on inferior Camaro exhaust systems, which may be true, but I have my doubts.

6 HP sounds about right. Steady-state flow suggests a little over half a psi reduction in backpressure across the muffler at max power can be achieved, which sounds reasonable.

All it takes is things like an eighth inch difference in pipe size or different elbows to make a small power difference. Or the tune might be just that much different.


Norm

[gajagfan]

Originally Posted by Rocky1974

I don't know whither it does or not, but the same option gives the Corvette an extra 6 horsepower, so I believe it "could". The fact that you can't find any literature supporting a horsepower gain, may have more to do with internal GM politics than actual horsepower gains. GM always keeps the horsepower ratings lower on the Camaro vs the Corvette, even when they have the same exact hardware. They always blame it on inferior Camaro exhaust systems, which may be true, but I have my doubts.

It will never happen, but wouldn't it be interesting to do back to back dyno tests on the same car, one pull without NPP, and one with?

[PYROLYSIS]

Originally Posted by gajagfan

It will never happen, but wouldn't it be interesting to do back to back dyno tests on the same car, one pull without NPP, and one with?

And they would both have to be 2013 SS's or newer as the electric power steering is said to save a few horsepower.

[Norm Peterson]

As long as the comparison runs were made on the same car on the same day, the model year or the presence of other options or different equipment should not matter. All you'd be looking for here would be the difference that NPP makes - all by itself. So it wouldn't matter if it ended up being something like 436 vs 430 or more like 400 vs 394.


Norm