NPP Exhaust Db Rating - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

shu92870 · 01-02-2021, 03:11 PM

I cant seem to find an actual answer as to what our
Camaro with NPP exhaust rating is.

Anyone have actual rating?

Or tracked Laguna Seca?
Any problems?
Can I get by with lifting?
I believe its a 90db or 92db day coming up.

ariZona28 · 01-02-2021, 05:58 PM

I'm facing a similar dilemma with a recently acquired vehicle. The facility in question (AMP, Phoenix metro area) has a limit of 96 DB @ 50ft. I downloaded an APP to my phone so I may attempt my own "sound check" in a few days. You may want to give it a try. I've been told my Z/28 w/NPP will pass with no problem. The Vette I'm playing with is a bit more boisterous!

Camaro2ss2010 · 01-02-2021, 06:43 PM

May not answer all of your questions but maybe this will help.

CamaroDreams76 · 01-02-2021, 07:14 PM

Autocross event i went to measured my car at 99db. I had highflow cats and stock headers. NPP valves were open.

They have a 101db maximum

shu92870 · 01-02-2021, 07:36 PM

Quote:

Originally Posted by Camaro2ss2010

May not answer all of your questions but maybe this will help.

Looks like I’ll definitely have to lift through the mic corner/corners.

Thanks that helps.

tartagliazl1 · 01-02-2021, 07:57 PM

I’m not familiar with that type of racing, but can’t you put them on a switch and keep them closed for the event. I programmed my NNP to open and close with the garage door buttons.

shu92870 · 01-02-2021, 08:14 PM

Quote:

Originally Posted by tartagliazl1

I’m not familiar with that type of racing, but can’t you put them on a switch and keep them closed for the event. I programmed my NNP to open and close with the garage door buttons.

1) I pulled my fuse.
2) Your not supposed to run the car with the flaps closed. I don’t want to add a button/controller.
3) Laguna Seca has noise restrictions in place. It’s city owned and it’s an expensive neighborhood. Even though the track was there first.

Southern Comfort · 01-02-2021, 08:28 PM

Quote:

Originally Posted by Camaro2ss2010

May not answer all of your questions but maybe this will help.

Source?

Camaro2ss2010 · 01-02-2021, 09:06 PM

Quote:

Originally Posted by Southern Comfort

Source?

Google “camaro npp exhaust decibel chart“ and click on images. It should be easily found that way. I have already closed the page or I would give you the link. Sorry

kaba · 01-02-2021, 09:38 PM

Quote:

Originally Posted by shu92870

2) Your not supposed to run the car with the flaps closed. I don’t want to add a button/controller.

Isn't forcing them shut strictly directing the exhaust through the muffler and closing off the more open tips?

Southern Comfort · 01-03-2021, 05:19 AM

Quote:

Originally Posted by Camaro2ss2010

Google “camaro npp exhaust decibel chart“ and click on images. It should be easily found that way. I have already closed the page or I would give you the link. Sorry

This looks like it.

https://www.mishimoto.com/engineerin...4-sound-check/

Google also returned a link to a mathematical formula for predicting sound level differences at different distances.

JD555 · 01-03-2021, 07:58 AM

Quote:

Originally Posted by shu92870

1) I pulled my fuse.
2) Your not supposed to run the car with the flaps closed. I don’t want to add a button/controller.
3) Laguna Seca has noise restrictions in place. It’s city owned and it’s an expensive neighborhood. Even though the track was there first.

That is like saying you cant run the car with a muffler. Where did you hear that? Its certainly isn't in the manual or they would give a way to keep them open in stock form.

shu92870 · 01-03-2021, 10:42 AM

Quote:

Originally Posted by JD555

That is like saying you cant run the car with a muffler. Where did you hear that? Its certainly isn't in the manual or they would give a way to keep them open in stock form.

Flaps run on ecu and open at 3500rpm. I can see if i can find the info.
But 1LE/ZL1/Z28 and i think some 2SS and 1SS had the NPP option.
Opening the exhaust flaps open the back pressure. Trying to run wide open with flaps closed would defeat the whole purpose.

Ill pass on setting up a button to try and hit to close flaps then Hit again to open after mic when running on a track wide open.

I think its an almost full throttle corner. Id rather work on hitting my line and slightly get off gas.

JD555 · 01-03-2021, 12:45 PM

I have the NPP but its still a muffler and not every SS has them. It will do no harm running closed. I get it it will be open when getting on it but you said you are not supposed to and that is not true. If you are worried wire them close them manually for the run.

01-02-2021, 03:11 PM	#1
shu92870 Drives: 2014 Camaro SS 1LE Join Date: Oct 2019 Location: Bakersfield CA Posts: 196	NPP Exhaust Db Rating I cant seem to find an actual answer as to what our Camaro with NPP exhaust rating is. Anyone have actual rating? Or tracked Laguna Seca? Any problems? Can I get by with lifting? I believe its a 90db or 92db day coming up.

01-02-2021, 05:58 PM	#2
ariZona28 Give speed a chance Drives: 2015 Camaro 2LS, 2015 Camaro Z/28 Join Date: Nov 2019 Location: Mesa, Az Posts: 2,234	I'm facing a similar dilemma with a recently acquired vehicle. The facility in question (AMP, Phoenix metro area) has a limit of 96 DB @ 50ft. I downloaded an APP to my phone so I may attempt my own "sound check" in a few days. You may want to give it a try. I've been told my Z/28 w/NPP will pass with no problem. The Vette I'm playing with is a bit more boisterous! __________________ 2LS: a TREMENDOUS machine. Z/28: it's a BIT MORE POWERFUL, of course.

01-02-2021, 06:43 PM	#3
Camaro2ss2010 Drives: 2010 Camaro 2SSRS M6 Join Date: Jan 2019 Location: Alabama Posts: 1,249	May not answer all of your questions but maybe this will help. Attached Images __________________ ECS supercharger, custom ground cam, ported throttle body, long tube headers, aeromotive fuel pump, fic injectors, ATI super damper, Corsa Extreme exhaust, elite engineering catch can and many other things.

01-02-2021, 07:14 PM	#4
CamaroDreams76 Tri-County Camaro SWFL Drives: 2013 IOM 2SS/RS/1LE Join Date: Apr 2013 Location: South West FL Posts: 3,082 View My Garage	Autocross event i went to measured my car at 99db. I had highflow cats and stock headers. NPP valves were open. They have a 101db maximum __________________ Just bolt ons........ https://www.camaro5.com/forums/showthread.php?t=343023

01-02-2021, 07:57 PM	#6
tartagliazl1 Drives: 2013 zl1 vert Join Date: Dec 2018 Location: Rochester, New york Posts: 956	I’m not familiar with that type of racing, but can’t you put them on a switch and keep them closed for the event. I programmed my NNP to open and close with the garage door buttons. __________________ 22% lower/ 2.5 upper/ 2” headers/ cat delete/ x-pipe/ 2 gallon x tank/ 100-3 pump/ fic 850/ dsx aux kit/ 103mm throttle body/ RPM 5” intake/ meth kit/ prometh lid injection/FI interchiller/ 160* stat/ ngk-7/ msd wires/ elite catch can/ tsp cam/ Che trunnions/ ported supercharger/ 1/2” lid spacer/ brick mod/BMR toe and trailing arms/ 751hp 757 tq SAE @17.3lb on a loaded dyno. Last edited by tartagliazl1; 01-02-2021 at 08:08 PM.

01-03-2021, 12:45 PM	#14
JD555 Drives: 2014 2SS RS, 6 sp man Join Date: Feb 2016 Location: Marlton, NJ Posts: 461	I have the NPP but its still a muffler and not every SS has them. It will do no harm running closed. I get it it will be open when getting on it but you said you are not supposed to and that is not true. If you are worried wire them close them manually for the run.