Larry B.

I just finished putting the Dynamat UNDER the rear carpet, directly to the floor via the self adhesive. I used Dynamat extreme and a layer of jute. I also have a Loyds mat on top.
The results were only a very slight change over just putting the material under the mat. The rpm at which the drone is most noticable actually changed. I can't say it is better or worse.... but it is different. I does get better as the engine warms up. Now I have to wait to see what the wife says.

Jagcvette

What type of transmission do you have?

Larry B.

A4 with 3.15 diff.

fredgpowell

If it is that bad then I would just take it off. Corsa has been known to have no drone but i dont know about fitment issues with the automatic trans. Hope you get it fixed. You might want to get some of that Dynamat under teh car while it is on a lift. Just a suggestion.

cerino2000

I can't think of any flowmaster system that doesn't drone.

30YR W8T

I agree about the Flowmaster drone. Last month I installed Flowmaster 40's in place of the stock mufflers on my C6 and needed to install Dynamat as well. The car sounds great going through the gears and when you step on it, but going down the highway at 75+ mph the drone is still fairly loud. However, there is no doubt the car liked the muffler change, so I will put up with the drone for now.

SellingBMWforC6

Thanks for the update. Time for an MN6 conversion?

DoSvdanye

What RPM are you running when it's droning? Most V-8's of any configuration drone at about 1600-1800 RPM. Just an inherent harmonic of a V-8. I had the opportunity to ride in an 06 Z06 a few weeks ago and it had a drone to it at those RPM's too. It was stock.

Larry B.

Hey.... I just noticed something.... The stock exhaust tips have a buch of little hole on the inner wall.. I know automakers don't do things for no reason.... I'm going to play around with some inserts with holes. I like tinkering with stuff... has anyone put the stock tips back on aftermarket mufflers?

30YR W8T

Yes, Thats exactly what I did. If you lossen the clamps on the exhaust pipes in front of the diff and pop the hangers loose you can pull just the two rear section out of the car. We cut the stock pipe and tips off at the mufflers. Flowmaster 40's are almost the same size and will fit in the same space, you are re-using the stock over axle pipe and tips. I think I read somewhere else on this forum where someone thoughts those holes were for some type of sound control.

aaaaa

They are supposed to reduce whistling

30YR W8T

A+4 thanks...that was it

need-for-speed

I have seen people try various methods to remove resonance once they install an aftermarket system with resonance (which includes most aftermarket brands). And I will never believe that an X-pipe will solve the problem either. I think that is just mind over matter , and "wanting" to believe the problem is gone. Since resonance occurs at such a low frequency, I can't see how dynamat would eliminate it either.

The only way to get rid of the resonance is to get rid of that exhaust and install Corsas or the OEM system. Good luck to you.

Larry B.

OK... I did some research on this... Tips with holes are actually called resonators. The are a few different types. Here's what I did. I got some reducers about four inches long, drilled holes (actually a lot) in the smaller diameter and inserted them small end first into the flowmaster tip...So now I have a dual wall type tip. WOW!! incredible ... The drone is almost COMPLETELY gone. I couldnot believe it. ALL of the annoying vibration/resonance gone. The sound is almost the same..... maybe a little quieter. I love to tinker with stuff and it is even better when it all works the way you plan it.

Blvdbrawler

Drone drone drone...I cant take it! Just leave the stock exhaust on if you dont want the car to sound good. Or simply buy yourself a pair of ear plugs...A lot cheaper than all these mats and the this and the thats...I mean really guys its a Corvette...A muscle car. What would you have done 20 years ago put a sock in the exhaust tips? Flowmasters are made to flow...Where theres more FLOW theres more sound. Is anybody under 60 years old on these forums?

Larry B.

I have had a lot of muscle cars. Muscle cars of years gone by didn't have the resonaton I spoke of. If you put a pair of glass packs on and no tail pipe... Leave them hang under the car.. you would get that drone. Only a few people young or old could stand that for more than a few days. And BTW.... more flow doesn't always help performance. Engines need some back pressure to be efficient with a stock cam and induction system. Tuning the exhaust controls the back pressure and is actually better than open pipes. Loud is not always better or faster. Lots of us older guys grew up with muscle cars. This is definetly not a old farts forum so give us a break.
Go check out the Mercury Grand Marquis forum.

30YR W8T

30YR W8T

Larry,
That was a cool idea and really cool if it did cancel some of the drone especially at the highway crusing rpms...1500-1800. How did you attach them so they would stay in place? Of course you know now I will be messing with this also.

30YR W8T

NFS,
You are absolutely right, an "X-Pipe" or H-pipe in my case will not eliminate the drone, however, Dynamat will and does reduce the heard resonance in a car. If you dont believe me, pull up the hatch mat and insulation from the back of your car then take a ride with the windows up, Dynamat does the same thing in principle as your mat and insulation by reflecting some of the sound waves back or absorbing them.

Tom400CFI

FYI, That's not accurate info.

There is a difference between velocity and "back pressure" no engine wants back pressure. Period.

-Tom