Ash flakes coming from exhaust - ZR-1 Net Registry Forums

Raykahn · 08-31-2024

This was something I noticed today upon starting the Z. These black flakes were coming out of the exhaust, mostly driver side. They are waxy on one side and matte on the other. I don't have cats, so wouldn't be from them. I'm thinking maybe some kind of resonator packing? My car has the Corsa catback setup. Car sounds normal, no lights popping up indicating a problem.

Has anybody seen anything like this? The one in the pictures is on the extreme large size from what I saw, most are very small.

WARP TEN · 09-01-2024

While I never saw this on my catless '95 or my catted '93, perhaps it could be just from carbon buildup that is finally flaking off. While not really related, I know that on the inside top of my Weber grill, it gets a buildup that looks like peeling paint, but the owners manual says it is just carbon and grease build up from cooking, so I use a wire brush to scrape it off. Would not surprise me that this might be possible in an exhaust system, especially if the car occasionally runs a bit rich. Just a thought. --Bob

Raykahn · 09-01-2024

Marc gave me a similar response, so that is probably not a bad assumption. He also informed me there is no packing in the Corsa resonators or mufflers, so its not that.

The car used to run very rich at WOT (below 10 AFR), but I dialed back the tune a while back. Perhaps this is just the build up finally coming out.

Mikey · 09-01-2024

Yeah looks like carbon flakes. Run some WOT on highway or somewhere when you can keep the pedal on the floor for some decent long pulls and you will clean more out.

09-01-2024	#2
WARP TEN Join Date: Apr 2007 Location: Lake Bluff, IL Posts: 2,088	Re: Ash flakes coming from exhaust While I never saw this on my catless '95 or my catted '93, perhaps it could be just from carbon buildup that is finally flaking off. While not really related, I know that on the inside top of my Weber grill, it gets a buildup that looks like peeling paint, but the owners manual says it is just carbon and grease build up from cooking, so I use a wire brush to scrape it off. Would not surprise me that this might be possible in an exhaust system, especially if the car occasionally runs a bit rich. Just a thought. --Bob __________________ 2016 Long Beach Red Z06 #10281 "POPS Z" 1995 Polo Green #409 "WARP TEN"--Haibeck 350/510 package, 4.10s, Hurst, Stock Exhaust with QTP Cutouts --Sold but still running strong 1993 Quasar Blue #161 "HIL KING" --Sold but still running strong, now with more than 120,000 miles 1967 Marlboro Maroon/Saddle Corvette Coupe 300 hp/4-spd --Sold a long time ago ZR-1 Net Registry Founding Member #95 NCM Lifetime Member Favorite Quote--Attributed to Mickey Thompson: "Too Much Horsepower is Almost Enough"

09-01-2024	#3
Raykahn Join Date: Jun 2022 Location: Virginia Posts: 84	Re: Ash flakes coming from exhaust Marc gave me a similar response, so that is probably not a bad assumption. He also informed me there is no packing in the Corsa resonators or mufflers, so its not that. The car used to run very rich at WOT (below 10 AFR), but I dialed back the tune a while back. Perhaps this is just the build up finally coming out.

09-01-2024	#4
Mikey Join Date: Jul 2020 Location: Nashville TN Posts: 323	Re: Ash flakes coming from exhaust Yeah looks like carbon flakes. Run some WOT on highway or somewhere when you can keep the pedal on the floor for some decent long pulls and you will clean more out.