Quote:
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.
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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.