Stingray Corvette Forum banner

1 - 20 of 51 Posts

·
Registered
Joined
·
39 Posts
Discussion Starter #1
I know there are a few threads regarding the NPP exhuast system.... But I dont beleive this has been thoroughly discussed.

My main item I want to discuss is again the aftermarket vs NPP.

I am about to place an order on Stingray and am curious if there is any benefit to ordering a NPP if I have intent to go aftermarket soon after. Are there aftermarket companies pursuing the possibility of integrating stock drive mode selector? And if so do you have to have a NPP equipped Stingray to take advantage of that?

Thanks for any insightful replies!
 

·
Registered
Joined
·
57 Posts
Sounds great when its on
I just wonder if its normal even with sound management off
it kicks into quiet mode at about 1500rpm and 35 mph
Still great option and car is so much better than my 07 C6 I had
which really surprised me
I would say go for it
Great to have option on sound
 

·
Registered
Joined
·
147 Posts
From what I've read, aftermarket exhausts will make use of the 4 valves from the stock NPP exhausts. I've seen several stock NPP exhaust systems for sale and the valves are not sold with them as they are fitted to the new exhaust. Not sure what happens if you buy an aftermarket system that does not use valves and you install it in a NPP optioned Stingray. I would think the system would throw a code when the connectors are not attached to the four valves units.
 

·
Registered
Joined
·
39 Posts
Discussion Starter #4 (Edited)
are the V4 valves only present on the NPP exhaust? because that would almost force my hand to purchase the NPP even if I intend to go aftermarket
 

·
Registered
Joined
·
658 Posts
I have the NPP and it sounds good stock and I love the way it functions.

However I added ARH long tubes and hi flow cats and the sound is amazing. I've had plenty of performance cars and this is the best sound car I've ever had.

With the driving mode in auto it's quiet and you can't even tell the car is a monster but once the valves open the car is loud and just sexy. Even driving with the valve open all the time there's no drone and fairly reserved until you step on it.

All in all the exhaust set up I have on my car is perfect for me and I can't believe the car sounds the way it does.... Sounds exotic.
 

·
Registered
Joined
·
4,656 Posts
are the V4 valves only present on the NPP exhaust? because that would almost force my hand to purchase the NPP even if I intend to go aftermarket
The front valves used for V4 operation are on all factory exhausts. The NPP exhaust has a baffling system in each muffler that will flow directly out of all 4 pipes when the second, rearmost set of valves is open. When those rear valves are closed the exhaust only flows out of the center 2 pipes using all of the internal baffling of each muffler.

If your car is not equipped with NPP the computer doesn't know there is a second set of valves so even if you install the NPP system and plug it in, assuming the wiring harness is even there (no one has confirmed that yet) the computer needs to be reprogrammed to enable the feature.

If you go aftermarket on an NPP equipped car then more than likely non of the valves will get installed and the system "may" throw an error code. If it doesn't throw a code it sill simply be sending signals to solenoids that no longer exist.

Bottom line, if you want a switchable exhaust buy the GM system, nothing in the aftermarket will touch it for price or performance, period! If you don't want switchable but want more noise than factory don't buy NPP.
 

·
Registered
Joined
·
39 Posts
Discussion Starter #10
Thanks again for the advice.... I may just get the NPP while I save up for the Corsa kits
 

·
Registered
Joined
·
463 Posts
Except incompatibility with AFM or other things, higher costs and negative resale impact.
The corsa is valve back, so you still have the one set. I haven't heard as of yet there being issues in 4 cylinder, is that what you mean by AFM? Of course it's costlier, it's aftermarket. The corsa exhaust sounds better IMO and the tips look wild. As for resale value, any car guy that mods knows that he has a back to stock sale before selling his ride.
 

·
Registered
Joined
·
489 Posts
Corey get the npp you will be happy with it if you want more aggressive sounds get headers and xpipe.
 
  • Like
Reactions: Sinner

·
Registered
Joined
·
39 Posts
Discussion Starter #14
I commited yesterday evening :). went with 2LT Z51. WITH NPP after reading all the advice/tips. Laguna blue, Kalahari interior, and all the black accessories of course. Couldnt do the 3LT, only because the Kalahari 3LT turns the entire dash tan. Doenst quite work with the exterior color scheme haha. And Napa wasnt a concern, not gonna be the daily driver :). thanks again for the help guys. And LOVE you Michael(H20)! haha, have to meet up in biloxi or something to waste some money.
 

·
Registered
Joined
·
16 Posts
I have the NPP and it sounds good stock and I love the way it functions.

However I added ARH long tubes and hi flow cats and the sound is amazing. I've had plenty of performance cars and this is the best sound car I've ever had.

With the driving mode in auto it's quiet and you can't even tell the car is a monster but once the valves open the car is loud and just sexy. Even driving with the valve open all the time there's no drone and fairly reserved until you step on it.

All in all the exhaust set up I have on my car is perfect for me and I can't believe the car sounds the way it does.... Sounds exotic.
Sinner would you happen to have a video of your setup? i also have the NPP and looking for headers. just curious to the sound.
 

·
Administrator
Joined
·
16,301 Posts
Whats the decibel rating at when the npp system is wide open?
loud :rolleyes: Too broad of a question. The db rating will vary based on how hard you stomp the gas peddle, where you are taking the measure, etc. Simple answer is that is is load and highly appropriate for the Stingray, yet fully in compliance with any DOT ordinances.
 

·
Registered
Joined
·
3,667 Posts
Whats the decibel rating at when the npp system is wide open?

On a dB A-scale, which I prefer to use for outdoor acoustic measurement under standard atmospheric conditions, the NPP exhaust is just slightly above the threshold of "wicked awesome"* at any RPM greater than 2000, let alone WOT!

*Measured using calibrated eardrums
 
  • Like
Reactions: RUMFITS

·
Registered
Joined
·
4,656 Posts
On a dB A-scale, which I prefer to use for outdoor acoustic measurement under standard atmospheric conditions, the NPP exhaust is just slightly above the threshold of "wicked awesome"* at any RPM greater than 2000, let alone WOT!

*Measured using calibrated eardrums
Too funny :)

BTW, we have nicknamed the car "Mad Dog" because of the way it barks and growls in the twisties with NPP open and rev matching.


Sent from my iPad using Corvette Stingray Forum
 
1 - 20 of 51 Posts
Top