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      05-17-2013, 10:34 PM   #1
mike519
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Dynamat for drone

OK, so I am thinking of trying to pick up some sound deadening material like Dynamat to line the truck and, if necessary, elsewhere. I like the sound of my SS Race cans but find drone at low RPM is likely what's bugging me.

I have never used mat like this before. In a roadster, will it help? I think it would if the drone is truly coming from resonance in the car's panels.

Any experience in using this specifically for exhaust drone would be appreciated.
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      05-17-2013, 10:51 PM   #2
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Why not trade it for a powerloop?
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      05-17-2013, 10:55 PM   #3
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Dynamat alone wont do anything for drone. I have SS Race and X-pipe, lined the entire trunk with Dynamat and the drone is still there. However, it help a little bit with the vibration. Dynamat basically a sound dampening.
Do a search, there were many discussions about it here.
The drone isn't too bad with the SS Race and most noticable at only certain RPM. I learn and dont stay in those RPM range.
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      05-17-2013, 11:27 PM   #4
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Quote:
Originally Posted by seank
Why not trade it for a powerloop?
You were serious in the other thread? If so, PM me...how old your powerloops are, pics, etc.
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      05-18-2013, 11:34 AM   #5
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I posted this in another thread on sound dampening road/tire noise in the roadster. I think the sounds outside the car creep in this way, and unless we address this area you'll still get some drone coming through, even if you use closed cell foam for example ................... but I could be wrong

http://www.zpost.com/forums/showpost...5&postcount=26

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      05-18-2013, 03:26 PM   #6
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Quote:
Originally Posted by mike519 View Post
You were serious in the other thread? If so, PM me...how old your powerloops are, pics, etc.
Kind of serious. I think it is closer to the .sound that you want but power loops are 2 times the price of the SS race exhaust if I remember correctly.

To bad you don't live closer, so we could trade back and forth.
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      05-18-2013, 04:35 PM   #7
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Something to consider. If you look at a number of exhausts on BMWs you will see a rubber and metal object bolted to the muffler or close to it on the pipes leading into the muffler, this is a frequency attenuation device. It dampens the frequency within its designed range (drone). A friend of mine who I trust, told me his even has a frequency indicated on his.

I have played around off and on with my Ford Expedition and it's straight through Magnaflow muffler which has terrible drone. I simply attached a 1 pound lead ingot to the intake side of the muffler and noticed a difference in drone level and quality. The change wasn't a night and day difference but it did take the hollow edge off the sound and slightly lessened the volume. Placement along the exhaust is important and seems to have it's greatest effect on or up against the muffler itself.

It might be worth the minimal amount of time and effort to pick up a pair of these from the local salvage yard and attach them to your mufflers. It might help.
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Last edited by Incompatible; 05-18-2013 at 07:01 PM..
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      05-18-2013, 05:02 PM   #8
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Quote:
Originally Posted by Incompatible View Post
Something to consider. If you look at a number of the exhausts on BMWs you will see a rubber and metal object bolted to the muffler or close to it on the pipes leading into the muffler, this is a frequency attenuation device. It dampens the frequency within its designed range (drone). A friend of mine who I trust, told me his even has a frequency indicated on his.

I have played around off and on with my Ford Expedition and it's Magnaflow muffler which has terrible drone. I simply attached a 1 pound lead ingot to the intake side of the muffler and noticed a difference in drone level and quality. The change wasn't a night and day difference but it did take the hollow edge off the sound and slightly lessened the volume. Placement along the exhaust is important and seems to have it's greatest effect on or up against the muffler itself.

It might be worth the minimal amount of time and effort to pick up a pair of these from the local salvage yard and attach them to your mufflers. It might help.
Good idea, will give it a shot, thanks.

Come to the conclusion that it sounds awesome from outside the car but its just the drone inside that bugs me. I may pick up some Dynamat and try it to see as well as the weight idea here.
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      05-18-2013, 07:02 PM   #9
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Quote:
Originally Posted by mike519 View Post
Good idea, will give it a shot, thanks.

Come to the conclusion that it sounds awesome from outside the car but its just the drone inside that bugs me. I may pick up some Dynamat and try it to see as well as the weight idea here.
Let us know how it turns out.
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      08-05-2013, 12:55 PM   #10
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The only thing Dynamat will do is prevent the body panels you apply it to from vibrating at low frequencies. Exhaust drone issues are mostly airborne noise, which Dynamat does not address. You'd need something much thicker, like 1-2" thick dense foam, to really make a difference. Even then, you'd have to basically apply it to the whole floor and trunk to completely seal the passenger cabin off.

Don't waste your money on Dynamat.
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      08-05-2013, 01:55 PM   #11
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Ideally what you want is both dynamat and closed-cell foam.
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      08-05-2013, 02:49 PM   #12
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Interesting discussion....
DKF was just telling me that they are looking at a drone elimination product to bring to our market.
It basically lets you dial in, or tune the exhaust to cure the dreaded drone.

I will be posting details in a poll very soon.
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      08-05-2013, 10:15 PM   #13
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I've had luck pumping something like this into the frame rails of cars to reduce road noise.

http://www.smooth-on.com/Rigid-and-F...122/index.html" rel="nofollow" target="_blank">http://<a href="http://www.smooth-on...index.html</a>

This is basically a pourable closed cell foam. You could easily pour it on flat surfaces. If you're creative you can cast it into or onto 3d surfaces. It's easily sanded and you can seal the top with epoxy and/or fiberglass. The 8lb is close to balsa and the 26lb stuff is close to the density of poplar or pine. It also is an excellent adhesive. It will stick to just about anything that isn't greasy or waxy.
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      08-05-2013, 10:44 PM   #14
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Honestly, you're gonna spend a bunch of time and money trying to fix the drone, when the only true solution is to replace it with a less aggressive muffer. If you want a bunch of noise, get electric cutouts
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      08-06-2013, 07:08 AM   #15
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Quote:
Originally Posted by inTgr8r View Post
Interesting discussion....
DKF was just telling me that they are looking at a drone elimination product to bring to our market.
It basically lets you dial in, or tune the exhaust to cure the dreaded drone.

I will be posting details in a poll very soon.
poll is up.... http://www.zpost.com/forums/showthre...1#post14449601
Sorry, its not an immediate solution, but an interesting concept rather that replacing the system as ZStig mentions.
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Last edited by inTgr8r; 08-06-2013 at 07:14 AM..
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