Valved Mufflers
Thread Starter
Cruising
Joined: Dec 2024
Posts: 10
Likes: 1
Valved Mufflers
Anyone know a company that sells valved mufflers? Have a 2007 Base. I know valvetronic sells them but I’m pretty sure they don’t fit. Reason for this is that I want to cam mine but don’t want it super loud all the time since it’s my daily and I don’t want to wake neighbors up all morning 😄
Pro
Joined: Apr 2016
Posts: 602
Likes: 243
From: Indiana
If you go the factory NPP route, the ‘06-‘10 Z06 mufflers can be modified fairly cheaply to be pretty rowdy open but very quiet closed. It’s a very cost effective solution as your all-in cost will be significantly less than aftermarket systems, especially if you can weld. ‘11 and up Z06 or any ZR1 mufflers are already rowdy from the factory, but will cost quite a bit more too.
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Race Director
Joined: Sep 2003
Posts: 16,836
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From: Database Error Indiana
Anyone know a company that sells valved mufflers? Have a 2007 Base. I know valvetronic sells them but I’m pretty sure they don’t fit. Reason for this is that I want to cam mine but don’t want it super loud all the time since it’s my daily and I don’t want to wake neighbors up all morning 😄
Le Mans Master
Joined: Dec 2013
Posts: 6,337
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From: Charles Town WV
2024 Corvette of the Year Finalist - Modified
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Can confirm valvetronic's fit. Talked to one of their reps last year who sent me videos of them on a c6z, bought a set and have them setting here just waiting to find the time to install.
Burning Brakes
Joined: Apr 2016
Posts: 1,120
Likes: 110
From: Chattanooga TN
Le Mans Master
Joined: Dec 2013
Posts: 6,337
Likes: 5,112
From: Charles Town WV
2024 Corvette of the Year Finalist - Modified
2023 C6 of the Year Winner - Modified
2022 C6 of the Year Finalist - Modified
I mean from what i could tell in the video they sounded pretty decent but that being said it wasn't the best quality video either. I'll try to get a good recording when I get mine installed, still need to buy tips and find the time to get it to my fab guy.
Pro
Joined: Apr 2016
Posts: 602
Likes: 243
From: Indiana
Out of curiosity, what do these sound like? How loud open/quiet closed? Do they compare to anything on the market? And finally, drone?
Looked them up and thought they might be a good drop in custom option to replace my factory NPP. Goal was to swap to Borla Atak as I absolutely loved it on my last Z06, but always open to other options.
Looked them up and thought they might be a good drop in custom option to replace my factory NPP. Goal was to swap to Borla Atak as I absolutely loved it on my last Z06, but always open to other options.
Supporting Vendor
Joined: Jan 2016
Posts: 82,030
Likes: 717
From: Orange County, CA
Out of curiosity, what do these sound like? How loud open/quiet closed? Do they compare to anything on the market? And finally, drone?
Looked them up and thought they might be a good drop in custom option to replace my factory NPP. Goal was to swap to Borla Atak as I absolutely loved it on my last Z06, but always open to other options.
Looked them up and thought they might be a good drop in custom option to replace my factory NPP. Goal was to swap to Borla Atak as I absolutely loved it on my last Z06, but always open to other options.
--Josh
Heel & Toe
Joined: Oct 2024
Posts: 17
Likes: 3
Valved mufflers
Texas Speed just came out with a valved axle back system. My stock npp mufflers on my 07 zo6 died on the last track day of 2024. Out of curiosity I cut them open and found massive cracks and a couple holes in the internal baffling. Anyway, I went with the texas speed valved axle back kit.
Word of warning, the zo6 kit does need some "massaging" to clear the differential cooler. This looks to only be an issue with the early Zo6. Mine is a 2007. My buddies newer c6 zo6 has a different differential cooler and should clear. Should fit perfect on a base corvette.
The sound with the valves closed is about the same as my stock zo6 npp mufflers. Zero drone at cruising. Open the valves and you release the hounds of hell. It gets very "aggressive" with the valves open.
Build quality is on par with the others such as Borla. High quality stainless thru out.
Would I go texas speed again? Yes, but I'd understand that the early zo6 may have differential cooler clearance issues and need adjustments.
Word of warning, the zo6 kit does need some "massaging" to clear the differential cooler. This looks to only be an issue with the early Zo6. Mine is a 2007. My buddies newer c6 zo6 has a different differential cooler and should clear. Should fit perfect on a base corvette.
The sound with the valves closed is about the same as my stock zo6 npp mufflers. Zero drone at cruising. Open the valves and you release the hounds of hell. It gets very "aggressive" with the valves open.
Build quality is on par with the others such as Borla. High quality stainless thru out.
Would I go texas speed again? Yes, but I'd understand that the early zo6 may have differential cooler clearance issues and need adjustments.
7th Gear
Joined: Feb 2026
Posts: 7
Likes: 0
Sorry for the dumb question here, but which valvetronic universal option? "Single Inlet Single Outlet" or "Single Inlet Dual Outlet" or the T style?
Just got the car and it's in storage so I'm not too familiar with the exhaust setup!
Thanks...
Just got the car and it's in storage so I'm not too familiar with the exhaust setup!
Thanks...
1st Gear
Joined: Mar 2026
Posts: 1
Likes: 1
i made the mistake of getting the dual outlet with a 3.0 outlet. It looks like **** but sound super mean.
they just stick out so far and it’s very difficult to get them in a good position. Much easier with a single to single
Unfortunately I will probably have to purchase a different set of mufflers and get it redone. If we aren’t able to reposition them
Melting Slicks
Joined: May 2018
Posts: 2,091
Likes: 600
From: Question Government
Your 3.0 outlets look fine, as long as they don't scrape going up driveways or over speedbumps. I'd use black muffler paint to spray everything visible but the 4 actual tips.
Last edited by RetroGuy; Mar 9, 2026 at 11:12 AM.