Black soot on outer pipes....
Thread Starter
Burning Brakes
Joined: Jul 2013
Posts: 1,147
Likes: 107
From: Cherry Hill PRNJ
Black soot on outer pipes....
I have a 2014 Z51 and have turned the "sound management" to "off" for that sweet burbling sound....when I have not had time to do a thorough detail job, I have noticed black soot on the two outer pipes...the inner ones look shiny....
I was thinking perhaps that turning the sound management off just bypassed the mufflers, but it doesn't sound loud enough to be just straight pipes as on some other beasts I have owned...
Anyone have an explanation for the soot?
I was thinking perhaps that turning the sound management off just bypassed the mufflers, but it doesn't sound loud enough to be just straight pipes as on some other beasts I have owned...
Anyone have an explanation for the soot?
Team Owner
Joined: Jul 2006
Posts: 97,155
Likes: 1,471
From: Calgary, AB. There's a reason why white was the only color offered on every year Corvette. Proud Canadian German Jamaican!
St. Jude Donor '09, '12-'13-'14-'15-'16-'17
normal, with the sound mgmt turned to the "off" position, 80% of the time the exhaust is heading out the outer pipes. I pulled fuse 42 and have the exact same thing, routine cleaning and polishing will relieve any permanent soot build up.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 34,840
Likes: 12,281
From: NE South Carolina
I have a 2014 Z51 and have turned the "sound management" to "off" for that sweet burbling sound....when I have not had time to do a thorough detail job, I have noticed black soot on the two outer pipes...the inner ones look shiny....
I was thinking perhaps that turning the sound management off just bypassed the mufflers, but it doesn't sound loud enough to be just straight pipes as on some other beasts I have owned...
Anyone have an explanation for the soot?
I was thinking perhaps that turning the sound management off just bypassed the mufflers, but it doesn't sound loud enough to be just straight pipes as on some other beasts I have owned...
Anyone have an explanation for the soot?
Last edited by JerryU; Jul 22, 2016 at 10:24 AM.
Team Owner
Joined: Nov 2007
Posts: 45,247
Likes: 8,509
From: Rochester, NY
Team Owner
Joined: Oct 2004
Posts: 25,583
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The richer starting gas mixture comes starlight out those lower restriction pipes versus going thru baffles in the muffler in the center pipes. That happens when you start regardless of the mode set. Until the exhaust gets hot, the water, which is a significant product of combustion, is liquid and causes the carbon to drip out.
If you don't let it build up over time, just a quick spray w/ detailer and a rag keeps them shiny. Even if you do let it build up, any metal polish very quickly takes care of the baked on soot.
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Thread Starter
Burning Brakes
Joined: Jul 2013
Posts: 1,147
Likes: 107
From: Cherry Hill PRNJ
The richer starting gas mixture comes straight out out those lower restriction pipes versus going thru baffles in the muffler in the center pipes. That happens when you start regardless of the mode set. Until the exhaust gets hot, the water, which is a significant product of combustion, is liquid and causes the carbon to drip out.
Melting Slicks
Joined: Apr 2002
Posts: 2,438
Likes: 590
From: Tellico Plains Tennessee
The two inner pipes are the fully muffled pipes. They are always open. The two outer pipes are the NPP "loud" pipes. They eliminate a lot of muffler when they open, thus louder. They get smutty when the NPP is open, path of least resistance, and stay clean when they're closed. If you look inside the two outer pipes you can see the NPP valves, butterfly type valves, that open by computer command. Or by removing the fuse, or by changing the driving mode, or by a switch installed by the owner. 
