Making dual mode exhaust loud

Tannero · 05-14-2025, 11:19 PM

Hey everyone.

I have a 2018 SS I put a Borla set of mufflers on and it sounds great.

I just picked up a 2021 zL1 and want to run it a little before I decide what I would like to modify if anything to it but want it to sound as loud as I can make the stock dual mode sound.

I set the drive sound to track.

Does pulling the fuse for the NPP valves make it any louder? Will it hurt anything like limiting back pressure?

Appreciate any input guys. Btw, the ZL1 is pretty damn impressive I must say from coming from a stock SS. Pretty impressed so far!

2018 Blue 1LE · 05-15-2025, 12:13 AM

Quote:

Originally Posted by Tannero

Hey everyone.

I have a 2028 SS I put a Borla set of mufflers on and it sounds great.

I just picked up a 2021 zL1 and want to run it a little before I decide what I would like to modify if anything to it but want it to sound as loud as I can make the stock dual mode sound.

I set the drive sound to track.

Does pulling the fuse for the NPP valves make it any louder? Will it hurt anything like limiting back pressure?

Appreciate any input guys. Btw, the ZL1 is pretty damn impressive I must say from coming from a stock SS. Pretty impressed so far!

WOW!!!!

Thanks for coming back from the future to let us know they bring back the Camaro.

RIPws6 · 05-15-2025, 04:33 AM

Quote:

Originally Posted by Tannero

Hey everyone.

I have a 2028 SS I put a Borla set of mufflers on and it sounds great.

I just picked up a 2021 zL1 and want to run it a little before I decide what I would like to modify if anything to it but want it to sound as loud as I can make the stock dual mode sound.

I set the drive sound to track.

Does pulling the fuse for the NPP valves make it any louder? Will it hurt anything like limiting back pressure?

Appreciate any input guys. Btw, the ZL1 is pretty damn impressive I must say from coming from a stock SS. Pretty impressed so far!

Pulling the fuse will help, but you might try buying the Range device to stop the car from deactivating cylinders and going into V4 mode. That does more to wimp out your exhaust note than the valves do in my opinion. Doing both would be great.

WhiteMale · 05-15-2025, 07:55 AM

Quote:

Originally Posted by RIPws6

Pulling the fuse will help, but you might try buying the Range device to stop the car from deactivating cylinders and going into V4 mode. That does more to wimp out your exhaust note than the valves do in my opinion. Doing both would be great.

One, Pulling the fuse will not make it louder it simply keeps the valves open all the time.

Two, it's a ZL1/LT4.

ZED SLED · 05-15-2025, 02:11 PM

^ what he said

Tannero · 05-15-2025, 08:56 PM

Quote:

Originally Posted by 2018 Blue 1LE

WOW!!!!

Thanks for coming back from the future to let us know they bring back the Camaro.

LOL - you got me!!! Ooops.... finger check.... 2018!

Tannero · 05-15-2025, 08:59 PM

Quote:

Originally Posted by RIPws6

Pulling the fuse will help, but you might try buying the Range device to stop the car from deactivating cylinders and going into V4 mode. That does more to wimp out your exhaust note than the valves do in my opinion. Doing both would be great.

Hey, thanks for the tip, didn't know you could deactivate that V4 mode - I'm going to look into that range device - never heard of it - thanks for that tip. Does sound pretty decent when the rpm's are up and it's in V8 mode, would be nice to see if that works!

ZED SLED · 05-16-2025, 07:18 AM

Quote:

Originally Posted by Tannero

Hey, thanks for the tip, didn't know you could deactivate that V4 mode - I'm going to look into that range device - never heard of it - thanks for that tip. Does sound pretty decent when the rpm's are up and it's in V8 mode, would be nice to see if that works!

When Whitemale mentioned in his post it is a ZL1/LT4 he was eluding to the fact that the LT4 in the ZL1 does NOT utilize AFM, so there is no V4 mode. This was only utilized in the LT4 for the Corvette. The hardware for it exists in the ZL1/LT4 but is turned off in the software.

Twizzty · 05-16-2025, 07:39 AM

When I put the back seat down it gets a little louder inside the car...

bishopts · 05-16-2025, 08:46 AM

The muffler is under the trunk and the seat muffles trunk noises. That's the case with all cars that have a trunk. Road noises will be more audible too.

Twizzty · 05-16-2025, 11:02 AM

you forgot it also helicopters over 80-90 mph with the windows down...

kropscamaro16 · 05-16-2025, 11:21 AM

afe power catback with npp will help alot!

Tannero · 05-16-2025, 12:00 PM

Quote:

Originally Posted by ZED SLED

When Whitemale mentioned in his post it is a ZL1/LT4 he was eluding to the fact that the LT4 in the ZL1 does NOT utilize AFM, so there is no V4 mode. This was only utilized in the LT4 for the Corvette. The hardware for it exists in the ZL1/LT4 but is turned off in the software.

Got it - thanks...

Tannero · 05-19-2025, 08:20 AM

Quote:

Originally Posted by kropscamaro16

afe power catback with npp will help alot!

I have been reading a lot of good comments on afe. Will consider for sure. Will try to find someone around me with them to hear them also. Txs for the reply.

05-14-2025, 11:19 PM	#1
Tannero Drives: 2018 SS / 2021 ZL1 Join Date: Jul 2020 Location: Lima, ny Posts: 40	Making dual mode exhaust loud Hey everyone. I have a 2018 SS I put a Borla set of mufflers on and it sounds great. I just picked up a 2021 zL1 and want to run it a little before I decide what I would like to modify if anything to it but want it to sound as loud as I can make the stock dual mode sound. I set the drive sound to track. Does pulling the fuse for the NPP valves make it any louder? Will it hurt anything like limiting back pressure? Appreciate any input guys. Btw, the ZL1 is pretty damn impressive I must say from coming from a stock SS. Pretty impressed so far! Last edited by Tannero; 05-15-2025 at 08:56 PM.

05-15-2025, 02:11 PM	#5
ZED SLED Drives: 2017 Mosaic Bk ZL1 M6 Join Date: Jul 2009 Location: South of Raleigh, NC Posts: 9,615 View My Garage	^ what he said __________________

05-16-2025, 07:39 AM	#9
Twizzty $$$$...$$...$$$...$$$$... Drives: 2021 Camaro 1SS 1LE Join Date: Jun 2019 Location: CFL Posts: 127 View My Garage	When I put the back seat down it gets a little louder inside the car... __________________ 2016 Focus RS MT - Sold 2018 Mustang GT A10 - Sold 2021 Camaro 1SS 1LE MT 2023 CX-50 Meridian Turbo 2023 KTM Duke 890 GP

05-16-2025, 11:02 AM	#11
Twizzty $$$$...$$...$$$...$$$$... Drives: 2021 Camaro 1SS 1LE Join Date: Jun 2019 Location: CFL Posts: 127 View My Garage	you forgot it also helicopters over 80-90 mph with the windows down... __________________ 2016 Focus RS MT - Sold 2018 Mustang GT A10 - Sold 2021 Camaro 1SS 1LE MT 2023 CX-50 Meridian Turbo 2023 KTM Duke 890 GP

05-16-2025, 11:21 AM	#12
kropscamaro16 Drives: 2016 1ss camaro Join Date: Feb 2016 Location: 909 Posts: 10,130	afe power catback with npp will help alot! __________________ 16 1SS NIGHTFALL GRAY METALLIC WITH NPP #BECAUSERACECAR #SAVETHEMANUALS

05-16-2025, 08:46 AM	#10
bishopts Drives: 2017 2ss 6mt Join Date: Mar 2024 Location: dallas Posts: 948	The muffler is under the trunk and the seat muffles trunk noises. That's the case with all cars that have a trunk. Road noises will be more audible too.

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