There was a guy here on evom last yr. who removed his spare tire and used some sort of can spray that foamed up then solidifies into a packaging material texture were he then cut it to completely fill the void.

 

He used Great Stuff and laid down plastic liner to put it in. Do not just pour several cans of that stuff in the trunk without a lining, you'll regret it and your car will hate you.

 

One thing that is very important is type and exact routing of the exhaust - I was surprised that a JDM bumper with a re-angled exhaust tip took all the drone out of my Tanabe Medallion Concept G.

Forget dynamat and other stuff like that unless you want a lead sled.

Some of the new sound deadening products are great - spray-on and very light. They convert sound waves into heat waves.

I have them in a street driven rally car (non-Evo) with a gutted interior and full cage. It is very pleasant to drive even long distances.

Some links below.

http://silentcoating.com/

http://www.summitracing.com/search/p...-type/spray-on

 

In essence, sound excites the metal making it vibrate. The vibration is (kinda) turned into heat. I'm pointing this out, because there's a difference and that difference lies in the structural rigidity of the car, itself. Very rigid car, not a big impact. In terms of sound insulation, there's only one way for it to happen and it involves a physical barrier. That barrier can consist of sheets of lead - arguably the more effective route, but obviously very heavy - an underbody coating as link'd above, or mass-load vinyl as another example. Laying down Dynamat in the trunk, or a similar product, is no different that putting down a heavy blanket, but with additional drawbacks. It's not a solution.

Look, folks, this is complicated. Most things are, once they're taken beyond a superficial level. Almost every time one of these threads comes up, I link Don's site. He took the time to distill the info and it only takes him a few pages of text to discuss the constraints. That's as simple as this gets.

 

Can you link to "Don's" site again? I find my newly acquired IX to be more noisy then I'd like and would be interested in that read.

 

sounddeadenershowdown.com

 

Dynamat the doors and the rear deck. Big help to my evo x!

 

Haha, i'm surprised pulling the jack/wheel and some of that ~2mil liner, but ok. I personally would say no dynomat, or any of the similar materials. I've used a lot of it and don't think its worth the weight IMHO... I would put the jack and stuff back in to see if that makes a diff..

 

So, here is a crazy idea that probably makes no sense to a more educated person.

Instead of laying Dynamat in the trunk, what if you layed it behind the rear seat to "seal" the trunk off? Would put the added weight more towards the center of the car in front of the rear wheels.

 

would the apexi active silencer be of any help in this situtation?

 

I've got a Greddy Evo 2 on my Evo and it is one of the quietest exhausts I've experienced

 

The most effective weight conscience way to do this is with a varex muffler. It's so quiet I leave it full open and i'm rolling around with no interior from the front seats back.

 

Maybe it's just your tires? And not the car. My car is loud but I really dont hear the road I hear everything else rumbling and shaking to death lol