[DGthe3]

Originally Posted by ParisTNDude

The LS3 engines in C6 Corvettes were rated at 430 HP and increased to 436 HP with the addition of the NPP exhaust.

Most of us spend a lot of money on axle back exhaust systems where the manufacturer claims as much as a 15 HP increase, but I doubt anyone could prove that with a dyno comparison of before and after. However, if you're a drag racer and .001 improvement in your ETs wins a race, you might appreciate 6 HP.

I'm confident the new engine is much more efficient than the LS3 and the HP increase with NPP may not be measurable. I added the remote actuated switch on my Grand Sport for the NPP since, when open and at steady speeds, it does have a minor drone to the exhaust sound. It doesn't bother me, but my wife wouldn't like it so I can close the valve when I want to.

And on the LT1 in the Corvette, its 5 hp.

Anyways, just about everybody would like more power. Thats not the point I was making.

Take two otherwise 2016 Camaro SS's, but have one with the NPP & one without. Race them side by side at the strip all day long, switching drivers & lanes frequently to try and isolate just the cars. Better yet, do it with about a dozen pairs of cars, in order to get a more representative sample (just in case one car was a lemon/factory freak). If you do all that, and analyze the timeslips identifying the car that was the faster on average in each pair, I bet that the odds that its the one with the NPP exhaust won't be much better than 60-40.

Why? Because between the 1% allowable difference in engine output allowed by the SAE & other tolerance-type differences (overall weight, drivetrain efficiency, etc) between supposedly identical cars, adding 1%-ish more power doesn't guarantee that it will be the faster car. The extra weight for the system probably takes away a decent chunk of the possible advantage that the NPP could provide. And yes, I am talking about ~10 lbs here ... no, its not very much but neither is 5 hp.

Anyways, getting back to our little imaginary testing scenario, the NPP car would already be faster in some pairs even if that exhaust did nothing. In others, the gains from NPP wouldn't be enough to overcome the cars other slight deficiencies. In the remainder, yes it would make the difference. But if it takes a day of drag racing a couple dozen cars to sometimes see if its the deciding factor ... I think its safe to say that there is no real difference in performance between the two.









I also think I need to clarify my suggestion that GM might only be advertising the higher number (if there is any difference between the two). My unsaid assumption is that when GM gives the rest of details on the 2016 Camaro (pricing out the rest of the accessories/options, giving fuel economy numbers, etc) they'd say something along the lines of "the 2016 Camaro SS makes 450* hp (*455 with NPP)" -not that they would forever hide the fact that the regular car makes less power than ones equipped with the optional exhaust.

I don't think GM will actually do this mind you, I was offering it as an alternative to them claiming no increased power.

[ParisTNDude]

Originally Posted by DGthe3

And on the LT1 in the Corvette, its 5 hp.

Anyways, just about everybody would like more power. Thats not the point I was making.

Take two otherwise 2016 Camaro SS's, but have one with the NPP & one without. Race them side by side at the strip all day long, switching drivers & lanes frequently to try and isolate just the cars. Better yet, do it with about a dozen pairs of cars, in order to get a more representative sample (just in case one car was a lemon/factory freak). If you do all that, and analyze the timeslips identifying the car that was the faster on average in each pair, I bet that the odds that its the one with the NPP exhaust won't be much better than 60-40.

Why? Because between the 1% allowable difference in engine output allowed by the SAE & other tolerance-type differences (overall weight, drivetrain efficiency, etc) between supposedly identical cars, adding 1%-ish more power doesn't guarantee that it will be the faster car. The extra weight for the system probably takes away a decent chunk of the possible advantage that the NPP could provide. And yes, I am talking about ~10 lbs here ... no, its not very much but neither is 5 hp.

Anyways, getting back to our little imaginary testing scenario, the NPP car would already be faster in some pairs even if that exhaust did nothing. In others, the gains from NPP wouldn't be enough to overcome the cars other slight deficiencies. In the remainder, yes it would make the difference. But if it takes a day of drag racing a couple dozen cars to sometimes see if its the deciding factor ... I think its safe to say that there is no real difference in performance between the two.

I also think I need to clarify my suggestion that GM might only be advertising the higher number (if there is any difference between the two). My unsaid assumption is that when GM gives the rest of details on the 2016 Camaro (pricing out the rest of the accessories/options, giving fuel economy numbers, etc) they'd say something along the lines of "the 2016 Camaro SS makes 450* hp (*455 with NPP)" -not that they would forever hide the fact that the regular car makes less power than ones equipped with the optional exhaust.

I don't think GM will actually do this mind you, I was offering it as an alternative to them claiming no increased power.

I don't disagree with anything you said. However, there must have been a reason GM designed the NPP considering the miniscule weight increase and extra circuitry to actuate it other than the sound. It doesn't operate in current cars except when engine RPM is above 3500. I'm assuming they believed it would positively effect the performance. A lot of us spend a ton of bucks on mods that increase HP by less than 6. I'm not sure the extra cost is worth it since spending that much money elsewhere might be more effective.

[mt3130]

Originally Posted by ParisTNDude

I don't disagree with anything you said. However, there must have been a reason GM designed the NPP considering the miniscule weight increase and extra circuitry to actuate it other than the sound. It doesn't operate in current cars except when engine RPM is above 3500. I'm assuming they believed it would positively effect the performance. A lot of us spend a ton of bucks on mods that increase HP by less than 6. I'm not sure the extra cost is worth it since spending that much money elsewhere might be more effective.

I'm only buying it to suppress the exhaust sound when I start my car early in the morning and drive through my community. I like the loud exhaust, but others don't. Even I don't want some jerk driving through my neighborhood at 5 AM doing that.

[DiGiam]

Originally Posted by Ragnar

All 5th Gen SS LS3's were rated for the same hp. You would have to think that electric assisted power steering and NPP would add something to the LS3.

The NPP for the Camaro was developed from the ZL1. I guess it was good enough to have as an option for the manual packages and still good enough for the Z28! I'm glad that I ordered it on my car, I would want it again.

Now, 6th Gen offers it right away and more packages! I can't wait to here one in person.

Exactly. The 13-15 electric power steering, npp, ls3 cars typically dyno around 380 vs 365 for the older models. My stock 1le made 382. I think GM didn't want to piss off some of the older Camaro owners by rating it at 440hp and they didn't want it to look like such a small hp gain from the 5th to 6th gen. It may be sort of the same thing with the vette. They don't want it to be the any closer to the vette's power

[jimmypop13]

Originally Posted by mt3130

I'm only buying it to suppress the exhaust sound when I start my car early in the morning and drive through my community. I like the loud exhaust, but others don't. Even I don't want some jerk driving through my neighborhood at 5 AM doing that.

I'm the same way but I thought I read somewhere that the npp on the new camaro will open wide when starting the car and then close up so there is a loud growl while starting. That defeats a little bit of the purpose on why I want it though. I want full manual control of the valves at all time. I need to find out exactly how the new system will work

[Number 3]

If it's like the Corvette used to be, you only had to pull fuse to have them open all the time. Many folks ran a switch to enable turning it on and off.

Open all the time can be pretty bad though. On the highway, it was miserable in a C6. But for distances, tolerable.

GM can't do this due to noise pass by, which is what this feature enables.

If you want, you could say it "cheats" the test.

[SSport16]

Originally Posted by jimmypop13

I'm the same way but I thought I read somewhere that the npp on the new camaro will open wide when starting the car and then close up so there is a loud growl while starting. That defeats a little bit of the purpose on why I want it though. I want full manual control of the valves at all time. I need to find out exactly how the new system will work

How ever you leave it when you turn off the car is how it will startup, so if you leave it in track, which is the loudest, it will startup in track/very loud.

[Marine Corps]

Wow, now I'm really confused. If the NPP option made any difference in the HP numbers I would have thought GM would have stated so. Since they haven't I'm inclined to believe that there's no HP increase. GM didn't hesitate to mentioned the 5 HP increase in Corvette.

[laborsmith]

Considering the history and influence of the Corvette managers, especially as regards the Camaro, I am wondering why any one is surprised. Or why there would be an expectation of anything different than what we have seen so far.

Laborsmith

[SSport16]

I am just happy that they gave the LT1 in the SS the same HP as the Vette, without the NPP of course...lol.

[Sinnthetic6]

I wish I knew where I saw it, I think it was with the original press releases when the 'official' unveiling occurred months back, but I specifically recall GM stating that horsepower for the SS was 450 and 455 if you choose the dual mode exhaust (NPP) option. I will see if I can find the article(s)

[tswilie]

I guess there is more difference in torque 469 to 465 in the vette. So 10 ft- lbs between the camaro and the vette

[xgnxs]

Originally Posted by tswilie

I guess there is more difference in torque 469 to 465 in the vette. So 10 ft- lbs between the camaro and the vette

...what? C7 is 460 tq without NPP, 465 tq with. Not sure where the 469 is coming from. Goes from 455 hp to 460 with NPP.

[tswilie]

Sorry about the fat fingered response, just on principle and audio pleasure I am hoping the dual mode exhaust provides a power boost in hp and torque. Even if it doesn't really your ears will be whispering to your brain "it's feels faster"