Exhaust Drone!
Thread Starter
Racer
Joined: Nov 2013
Posts: 338
Likes: 8
From: South NewJersey
Exhaust Drone!
I have Headman headers to 2 1/2" pipes with X where Cat used to be with Dynomax mufflers. My engine is mildly built with a 515 lift cam.
At idle it sounds nice but at around 1500-2000 rpm the drone is bad. Upwards in the rpm range it gets better. I know this has beem discussed in depth but I tried a search and the topic really cluttered. any info or ideas would be great. Happy holidays!!
At idle it sounds nice but at around 1500-2000 rpm the drone is bad. Upwards in the rpm range it gets better. I know this has beem discussed in depth but I tried a search and the topic really cluttered. any info or ideas would be great. Happy holidays!!
Instructor
Joined: Aug 2016
Posts: 209
Likes: 24
It's the Dynomax mufflers. I had a Dynomax cat back with a Cat delete pipe on my mostly stock L98. I had stupid amounts of drone. It was louder inside the car then it was outside. I swapped out the Dynomax cat back for a Flowmaster set up and it was 1000% better. Now the Flowmasters are not perfect either but the car is a lot more enjoyable to drive and it is louder outside of the car then inside.
Instructor
Joined: Aug 2016
Posts: 209
Likes: 24
I just changed the mufflers and was much happier. With the headers it will be louder then mine. Adding high flow cats would tone it done some more if needed without hurting your performance. I would start with changing the mufflers and see how it sounds.
Cruising
Joined: Mar 2017
Posts: 12
Likes: 0
From: Hawaii
Recently ordered installed then removed the Borla catbacks for same reason, drone! It reminded me of riding around with open headers except less decibels but same super resonance. My wife hated it. I kinda' like it and might put it back on. I know is kinda' false advertising though no horsepower to back up all that sound. some day Melrose smooth flows.
Last edited by L98-C4-HI; Dec 21, 2017 at 08:49 PM.
Melting Slicks
Joined: Jan 2009
Posts: 3,482
Likes: 196
From: folsom california
It's the Dynomax mufflers. I had a Dynomax cat back with a Cat delete pipe on my mostly stock L98. I had stupid amounts of drone. It was louder inside the car then it was outside. I swapped out the Dynomax cat back for a Flowmaster set up and it was 1000% better. Now the Flowmasters are not perfect either but the car is a lot more enjoyable to drive and it is louder outside of the car then inside.
Le Mans Master
Joined: Aug 2015
Posts: 6,090
Likes: 1,972
From: St. Charles MO
FWIW, my car has LT headers, cats, and X-pipe instead of the stock resonator, and then Corsas at the back. It still has bit of a drone from about 1700-2000rpm, although it isn't anything close to unbearable/terrible. But this is just to say that Corsas are not a guarantee of no drone at all.
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Safety Car
Joined: Jun 2010
Posts: 4,564
Likes: 1,676
FWIW, my car has LT headers, cats, and X-pipe instead of the stock resonator, and then Corsas at the back. It still has bit of a drone from about 1700-2000rpm, although it isn't anything close to unbearable/terrible. But this is just to say that Corsas are not a guarantee of no drone at all.
Le Mans Master
Joined: Aug 2015
Posts: 6,090
Likes: 1,972
From: St. Charles MO
Well, technically the previous owner did. OTOH, if you hear it wail in its power band, you might assess it differently. It does sound spectacular, and I got lots of compliments on the music it makes. So it's a tradeoff.
More pertinent to this thread, the OP's car also has an X-pipe, so my experience may be especially helpful to him.
More pertinent to this thread, the OP's car also has an X-pipe, so my experience may be especially helpful to him.
Racer
Joined: Jul 2017
Posts: 422
Likes: 53
From: PA
I have Headman headers to 2 1/2" pipes with X where Cat used to be with Dynomax mufflers. My engine is mildly built with a 515 lift cam.
At idle it sounds nice but at around 1500-2000 rpm the drone is bad. Upwards in the rpm range it gets better. I know this has beem discussed in depth but I tried a search and the topic really cluttered. any info or ideas would be great. Happy holidays!!
At idle it sounds nice but at around 1500-2000 rpm the drone is bad. Upwards in the rpm range it gets better. I know this has beem discussed in depth but I tried a search and the topic really cluttered. any info or ideas would be great. Happy holidays!!
Team Owner
Joined: Jul 2004
Posts: 28,422
Likes: 3,275
From: Hartford WI
My conscience kinda died but I installed a single cat because I wanted to kill some of the noise from the LT headers and Borla Stinger system. It made the car somewhat irritating to the wife as opposed to "I don't want to sit in that car". I am looking at the Corsa system to see if someone has a take off or used one.
Tech Contributor
Joined: Jun 2004
Posts: 20,855
Likes: 959
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
I had drone issues on my non-C4 '69 at 1500 RPM with several exhaust configurations. Flowmasters were the worst. After 12 miles of driving with the Flowmasters I threw them away. I still had some drone with the new Dynomax mufflers, but it was at least tolerable. I took Vizard's advice (from one of his books) and put an H pipe right at the header exits/reducers. This got rid of about 90% of the drone, and the car is now quite pleasant to drive.
Team Owner
Joined: Jul 2004
Posts: 28,422
Likes: 3,275
From: Hartford WI
I had drone issues on my non-C4 '69 at 1500 RPM with several exhaust configurations. Flowmasters were the worst. After 12 miles of driving with the Flowmasters I threw them away. I still had some drone with the new Dynomax mufflers, but it was at least tolerable. I took Vizard's advice (from one of his books) and put an H pipe right at the header exits/reducers. This got rid of about 90% of the drone, and the car is now quite pleasant to drive.
Drifting
Joined: Jul 2009
Posts: 1,257
Likes: 98
From: Ashland PA
2021 C4 of the Year - Modified Finalist
you could try blocking one exit on each muffler, I did that on my last exhaust and the OBX I have now. you could try just shoving some steel wool in there just to try to see if it works then if you decide you like it plug it permanently.
Thread Starter
Racer
Joined: Nov 2013
Posts: 338
Likes: 8
From: South NewJersey
Thanks for All replies and info. I have also noticed my muffler tips are about two inched back under the rear valance. I would think moving mufflers back and behind the car would help also. I would love to get a pair of Corsa mufflers but I dont think you can just buy mufflers. the rest of my exhaust is fairly new. I tried to use older mufflers when I had the exhaust done. Now I need to address this. Merry Christmas.
Zen Vet Master Level VII
Joined: Mar 2016
Posts: 5,218
Likes: 1,174
From: Southlake, TX
Franklin, you are wanting a bit of both ends of the spectrum; high performance low restriction that yeilds big power and throaty sound.... but with no drone. (corsa fans jump in here and smack me)
You have to have a strategy and then go for balance and your definition of balance.
Of all the countless threads on this subject the only consistent "Zero Drone" solutions come from choice of THE MUFFLERS and not combinations of the headers, cross over, X pipes etc. 2.5 vs 3 inch pipes.
So, for zero/lo drone your choice is either Corsa Mufflers or a OEM/Walker solution. Frankly it dosen't matter what you do upstream.
