We all know dynamat does prove results... and for the most part i always see people use one solid sheet.

At Toby's shop i saw that all it took was one piece of dynamat to stop the little bell from making much noise at all.

That got me thinking, instead of using the entire sheet to cover up one panel, could i cut up a sheet, spread the blocks into a checkerboard pattern and cover more surface area on say two panels instead of one? would it lose effectiveness dramatically or is there really no difference at all and the single sheet thing is mainly for aesthetics? (and because no one wants to waste all that time sticking a hundred little blocks in their car.

I've never had experience with dynamat and the horrible flex my old ass car makes from the trunk makes me cringe when i hear it from the outside.
I'd like to get a practice packed down well so when i finally buy a Z32 I can put down some dynamat, if needed, in the most effective way.



I've also heard about doubling up on it? Any point to that or is it kinda like adding that 4th coat of lacquer, isn't necessary but for some reason you feel like it might. (ignore the actual number, i'm just making a point)


Thanks.

 

i don't know much about the dynomat itself, however, i have a basic understanding of the physics behind the vibrations.
The checker board pattern would cover more area however, not more surface area. that seems to be the key. the more surface area covered, the less vibrations. you can have a little hole and that will allow for vibrations and sound loss. doubling it up would benefit, but probably not in a very noticable way. Maybe if you were pushing 150+db then maybe that would help, but your standard set up wouldn't gain that much considering the cost.
like i said, i don't know alot about dynomat, just basic knowledge, so I might be way out in left feild.

 

I gave up on matting, I will do my doors. But I have 3 layers on my trunk lid and it still rattles liek crazy.

 

Its not so much my trunk lid making the noise, its the surrounding panels for the actual trunk, like the side wall or something... i wanted to get a bit of dynAmat and cover those two and hopefully prevent it from sounding like complete crap but I guess that'd be pointless.... im going to just not touch money for about 6-8 months till i buy a Z32. I'll worry about it after the car is in my driveway.

 

Dynamat works a couple of ways. One is by just adding weight to a panel, thereby requiring more energy to vibrate it. Second, it is semi-viscous, vs a pure solid, which also helps suck up vibrational engery.

Covering an entire panel would maximize both of these, but smaller pieces can be used effectively, as well. If you put a strip of dynamat across a trunk panel, for example, it will keep vibrations from running across it...kind of like an island keeping the ocean waves from going through it. Obviously, the more you can put on, the better, but I don't think its linear...ie, twice as much dynamat does twice as much good.

The roof of my caprice only has three strips of dynamat on it...I think they are like 15x30, or something, and it doesn't vibrate much.

Now, if I'm doing a door skin, then my goal is not only vibration dampening, but rear wave blocking. I'll try and cover all of the factory access holes, keeping the rear wave from coming around and cancelling the front wave. Here, I'll probably end up covering the hole skin.

Short answer...some is better than none, and might not be any worse than lots.

Toby

 

I have the sides of my trunk dynamatted and it seems to do the job for that area, still flexes but doesn't rattle.

 

exactly thats what i need it for.

The trunk lid is expected to rattle but i hate that the side walls do it too, it sounds extra terrible.



Thanks Toby and 727 for the info.