Non NPP vs NPP on non npp car
Thread Starter
Melting Slicks
Joined: Aug 2010
Posts: 3,063
Likes: 82
From: Tumwater, WA
Non NPP vs NPP on non npp car
I am trying to get some sound clips that show the difference between a non npp exhaust and a npp exhaust on a non npp car. Im assuming that if I put a NPP exhaust on a Non NPP car that the exhaust will always sound like the NPP with valves open? And will the AFM valves on my Non NPP car still work if I do the swap? Im sure this is probably the cheapest way for me to increase my exhaust note some. Thanks.
Melting Slicks
Joined: Jun 2004
Posts: 2,087
Likes: 1,361
From: Macon GA
I’ve got an NPP exhaust waiting to go on my non-NPP car now…I got it for free from a member here who just wanted it gone. I just had to go get it. The AFM valves will work as normal, but yes the NPP valves will just be open all the time…
Melting Slicks
Joined: May 2005
Posts: 2,990
Likes: 330
From: Key Largo Florida
Thread Starter
Melting Slicks
Joined: Aug 2010
Posts: 3,063
Likes: 82
From: Tumwater, WA
Love to hear how you feel about the sound/volume difference when you put it on. Not too many C8s around here so it may take a bit to find a NPP exhaust.
Thread Starter
Melting Slicks
Joined: Aug 2010
Posts: 3,063
Likes: 82
From: Tumwater, WA
I'd say yes and yes to your questions. I had NPP exhaust on my C7 and always left it loud. I've purchased a Z51 exhaust just haven't put it on yet. Should happen in the next week or two.
https://youtu.be/jS57w33KrLw?si=iDqdUxPaQPaKaa6e
https://youtu.be/jS57w33KrLw?si=iDqdUxPaQPaKaa6e
Cool there is a difference and probably just right for me. Where I live the house are real close so done want to wake to whole neighborhood. Also waiting to see what yall will pay for install or are yall doing it yourself?
Safety Car
Joined: Jan 2005
Posts: 4,508
Likes: 1,460
From: Pittsburgh PA
2025 C8 Stingray of the Year Finalist - Unmodified
2024 C8 of the Year Finalist - Unmodified
I have been playing with the same idea. Should be able to get one for free in August at Carlisle where they are piled up next to the aftermarket installations tents. I'm not really dissatisfied with the base exhaust and absolutely refuse to pay a few thousand $$$ for a set of mufflers and pipes.
Melting Slicks
Joined: Jun 2004
Posts: 2,087
Likes: 1,361
From: Macon GA
…I’m at 2700 miles on my ‘24, but plan to put on the NPP exhaust maybe this summer. I got it for free, but drove 200 miles to go get it…still well worth getting a free exhaust!
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Advanced
Joined: Dec 2021
Posts: 67
Likes: 39
I just swapped an NPP into a non-NPP. Sounds better but not incredible. Cold start is killer tho. For a free exhaust system or super cheap, its worth it versus thousands for after market. If installing it yourself, it's a pain and you will need a second hand.
Le Mans Master
Joined: Mar 2001
Posts: 8,471
Likes: 3,970
From: Omaha
2020 Corvette of the Year Finalist (performance mods)
C4 of Year Winner (performance mods) 2019
NPP open all the time is decent, but still too quiet for many. We put 8K miles on our 23 SR with NPP before getting the Z06, probably 80% of those miles with the NPP set to Track, and my wife never once complained about it. There's really no downside as there's no drone (due to the AFM flaps still working), but under about 4000rpm, it's still pretty quiet in the car. If you can get an NPP for free/cheap, it's worth considering.
By comparison, on the very first drive in the Z06 in Tour mode my wife said it was loud.
By comparison, on the very first drive in the Z06 in Tour mode my wife said it was loud.