Exhaust drone - recently started
08-06-2015, 03:35 PM
#1
Burning Brakes
Thread Starter
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; 08-06-2015 at 04:02 PM.
08-06-2015, 04:03 PM
#3
Race Director
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
08-06-2015, 07:15 PM
#4
Burning Brakes
An H-Pipe just forward of your spare tire cover, between 1" holes in the pipes. (around $60.00 at your local muffler shop.)
08-07-2015, 07:13 AM
#5
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.
08-10-2015, 09:56 AM
#6
Burning Brakes
Thread Starter
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.
09-22-2015, 09:36 AM
#7
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.
09-22-2015, 11:14 PM
#8
Burning Brakes
One quick question DrDyno... Once you made this mod, other than curing the droning problem, did it change the tone of your exhaust?