Exhaust drone - recently started
Thread Starter
Burning Brakes
Joined: Jul 2012
Posts: 945
Likes: 32
From: WV
Exhaust drone - recently started
This is my second year tracking my 1993 LT1, 6 spd.
The car has aftermarket shorty headers, stock cats and resonator, and 3 inch exhaust feeding Magnaflow mufflers.
Recently the exhaust has become a good bit louder and a very noticeable drone has developed. The drone starts around 2000 rpm and fades away beyond 2500 rpm.
I dont mind the louder exhaust, but the drone is annoying.
I have inspected the full length and dont find any leaks. Im guessing that the internals of either the cats or the resonator have worn out. From inside the car, the drone sounds very near, making me suspect cats the most, but thats hard to say.
Any ideas on what has caused it and how to correct it? Gut the cats? Replace resonator with X pipe?
The car has aftermarket shorty headers, stock cats and resonator, and 3 inch exhaust feeding Magnaflow mufflers.
Recently the exhaust has become a good bit louder and a very noticeable drone has developed. The drone starts around 2000 rpm and fades away beyond 2500 rpm.
I dont mind the louder exhaust, but the drone is annoying.
I have inspected the full length and dont find any leaks. Im guessing that the internals of either the cats or the resonator have worn out. From inside the car, the drone sounds very near, making me suspect cats the most, but thats hard to say.
Any ideas on what has caused it and how to correct it? Gut the cats? Replace resonator with X pipe?
Last edited by emptnest; Aug 6, 2015 at 04:02 PM.
Race Director
Joined: Sep 2001
Posts: 14,679
Likes: 752
From: NEwhere Ohio
When I've had this happen it's always been a leak somewhere.
I start the car up and, as its warming up, move my hand down the whole length of the system feeling for puffs of air
Don't do this when its hot, cause you will get burned obviously.
My recent leak was at a junction where this was an exhaust band clAmp. No matter how many times I adjusted it and re cranked down the clamp it still leaked.
I finally put RTV silicone and it quit leaking
I start the car up and, as its warming up, move my hand down the whole length of the system feeling for puffs of air
Don't do this when its hot, cause you will get burned obviously.
My recent leak was at a junction where this was an exhaust band clAmp. No matter how many times I adjusted it and re cranked down the clamp it still leaked.
I finally put RTV silicone and it quit leaking
Burning Brakes
Joined: Nov 2013
Posts: 914
Likes: 277
From: St. Petersburg FL
An H-Pipe just forward of your spare tire cover, between 1" holes in the pipes. (around $60.00 at your local muffler shop.)
Melting Slicks
Joined: Apr 2007
Posts: 2,616
Likes: 111
When I've had this happen it's always been a leak somewhere.
I start the car up and, as its warming up, move my hand down the whole length of the system feeling for puffs of air
Don't do this when its hot, cause you will get burned obviously.
My recent leak was at a junction where this was an exhaust band clAmp. No matter how many times I adjusted it and re cranked down the clamp it still leaked.
I finally put RTV silicone and it quit leaking
I start the car up and, as its warming up, move my hand down the whole length of the system feeling for puffs of air
Don't do this when its hot, cause you will get burned obviously.
My recent leak was at a junction where this was an exhaust band clAmp. No matter how many times I adjusted it and re cranked down the clamp it still leaked.
I finally put RTV silicone and it quit leaking
Mine started that, (not droning) but has gotten louder and started popping as well; it has developed an exhaust leak somewhere.
Thread Starter
Burning Brakes
Joined: Jul 2012
Posts: 945
Likes: 32
From: WV
When I've had this happen it's always been a leak somewhere.
I start the car up and, as its warming up, move my hand down the whole length of the system feeling for puffs of air
Don't do this when its hot, cause you will get burned obviously.
My recent leak was at a junction where this was an exhaust band clAmp. No matter how many times I adjusted it and re cranked down the clamp it still leaked.
I finally put RTV silicone and it quit leaking
I start the car up and, as its warming up, move my hand down the whole length of the system feeling for puffs of air
Don't do this when its hot, cause you will get burned obviously.
My recent leak was at a junction where this was an exhaust band clAmp. No matter how many times I adjusted it and re cranked down the clamp it still leaked.
I finally put RTV silicone and it quit leaking
I found a joint dripping condensate. Sealed it and almost all of the drone was eliminated. The remaining drone is limited to about a 100 rpm range.
I think I may seal all the joints next time it's up on stands.
Intermediate
Joined: Dec 2014
Posts: 35
Likes: 0
For storing my 99 vette for the winter, last year I used a trickle charger at home where I could see it. This year I will store my Vette away from home. Can I take my battery out for the winter and bring it home. Will this cause any problems next May with the computers? ETC.
Burning Brakes
Joined: Mar 2008
Posts: 881
Likes: 24
From: Coquitlam BC
One quick question DrDyno... Once you made this mod, other than curing the droning problem, did it change the tone of your exhaust?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski