Can't stand the drone anymore

its an undercar resonance, very hard to get rid of. I tried for years, tried every system, every trick.


I finally killed the drone, the fix is in here


Bob
 
I did a little more observing of the sound last night, it seems like from 1700-1900 rpm is where the sound tends to boom and drone. Downshifting to a higher rpm makes this go almost dead quiet. :confused:



Problem solved......... Drive faster!!! :biggrin:
 
its an undercar resonance, very hard to get rid of. I tried for years, tried every system, every trick.


I finally killed the drone, the fix is in here


Bob

That was good reading Bob, thanks.

In fact, I appreciate everyone taking time to post these suggestions. :D
 
I'm on my 2nd car with a 2-1/2" Pitbull system, and I don't think it's bad or loud at all. It really doesn't sound all that much different than the Hooker system I had on the last GN.

My buddy Jim V had the 3" single shot on his car... and I thought it sounded like a Kenworth. I didn't like it at all. I can't imagine a 3.5-4" single being any better... and in all liklihood, it's probably worse.

If I get another system, it will be one of the new 3" dual systems that's now available.
 
its an undercar resonance, very hard to get rid of. I tried for years, tried every system, every trick.


I finally killed the drone, the fix is in here


Bob

Very good read, Bob. It has actually got me rethinking my love for loud exhaust. Seems to be more logical to quiet down the noise. Well, the read of all those posts on the subject just put it all in a different perspective, and it made sense to me. Time to "rethink" loud pipes. Thanks for the read, Bob. And very good solution to exterminating the drone.

Bruce '87 Grand National
 
Very good read, Bob. It has actually got me rethinking my love for loud exhaust. Seems to be more logical to quiet down the noise. Well, the read of all those posts on the subject just put it all in a different perspective, and it made sense to me. Time to "rethink" loud pipes. Thanks for the read, Bob. And very good solution to exterminating the drone.

Bruce '87 Grand National

Although..... side pipes on a v8 have their place, Bruce. ;) :D



I believe I'm going to try a crossflow setup. One benefit right off the bat is the twin stainless tips that exit in the stock locations. I always felt the single shot left the car with just a hint of the unbalanced look when viewed from the rear.


Funny thing is I really like the sound of my open downpipe. I hear the turbo spool quite nicely.
 
I have the Hooker bolt-on dual system with a high-flow cat. Drones real nice around the parking lot, zero everywhere else. I might lose a tenth or two somewhere, but you will never care unless you run for slips every day.
 
I also read somewhere that installing a brace between the two rear framerails kills the drone, something to do with the harmonics. Haven't tried it.
 
I read the same thing so i replaced both rear frame mounts ,,it did not help,the post said the 2 frame rails acted like a tuning fork...;)..the only way that i removed a terrible drone and also some noiise on my hooker cat back with aero chambers was to install a third muffler (crossflow) in the system,,,now i am happy no drone less noise
 
ATR Crossflow Drone

I have an ATR 3" crossflow system and the drown is rediculous! The worst I have ever heard. I hope the new crossflow systems dont do the same thing!
 
There is one big thing that we haven't mentioned. Stick your air filter in a can.

Yes.. you can try it with an ATR 14" box or kenne belle 9" box.. putting your air filter inside the can.. even with the bottom cut out will take out a bunch of drone.

Also.. it's in the mufflers.. the Dynomax Race Magnums in mild steel are the most quite mufflers they dynomax made - definitely quieter than Edelbrocks, magnaflows, etc.. Even more quiet than the stainless versions - verified by Dynomax tech.

That's what I had on my car.. ATR 14" K&N/can and dynomax race magnum mufflers. I don't think there were many more quiet than my old car.
 
I also read somewhere that installing a brace between the two rear framerails kills the drone, something to do with the harmonics. Haven't tried it.

I have a piece of shallow uni- strut on mine not much different, I read use some 1" square stock I might try that and the intake canister, I have a TR cold air filter down low the sound on mine is not too bad if I crack the window some
 
I tried the cross braces, didn't help.

I tried the Borla venturis (I installed 3 of them), didn't help.

I put a flex section in place of the cat, didn't help.

I used every type of muffler, changed it some , but never eliminated the drone.

There was also the idea to cut slots in the tailpipes, I never tried that.

The triple muffler setup is the only thing that worked.

Bob
 
I also cut the slots in the tailpipe ha ha and i was so pissed off i used a grinding disc and really did some slots and it doesnt work .
 
I don't think there were many more quiet than my old car.


When I first drove my car after the new system was installed the thing that struck me the most was when I was sitting at a traffic light with the stereo set for a nice comfortable level, and when I pulled away from the light I didn't need to change the setting. It was the oddest thing, as I was in the habit of turning it up and down in city stop-and-go.

Bob

I'm not sure the intake can will make a difference, as at light throttle angles any intake noise is muffled by the turbo, intercooler, etc.
 
The intake can definitely works.. The factory does a ton of work on factory airboxes to get rid of resonance, etc. that's why modern intake tubes look funky.
 
Intake noise generally occurs at WOT. We are talking about drone at part throttle cruise.

Bob
 
Anybody ever try an exhaust wrap to see if it changed anything? Maybe dynamat in the floor board area?
 
It has its uses....

Was out cruzin with the family this past weekend and we were on a long 30mph stretch and as the car was droning away, the wife looks over at me and says " Ya know what I like best about this car? At a certain speed, the noise it makes totally drowns out the sound of the kids jabbering away in the back seat".

We're fine with the drone.:biggrin:
 
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