slicky rick

The 991 is being complemented as having a lot better noise management. Tire noise in the 997 has been the major compalint that seemed to have been addressed in the 991 design. My question is, though for sure no simple mod can improve tire road noise drastically but has anyone tried to add sound deadening material in the right places to reduce these tire and road noises. I am not talking about worn tires here as some of the other posts. I am referring to good sound deadening materials place in strategic points to lessen intrusion of tire and road noise in the cabin...this should be a good exercise.

Byprodriver

Are you talking about new Porsche approved N rated tires? If so DynaMat is great for lining floorpans etc.

okbarnett

I have noise dampening material in a 996 and 997. It helps alot. Since I removed the rear carpet to use gt3 type carpet, I put in material over the entire rear tub section and floor, what ever i can get to. It doubles the noise reduction of the carpet.
You are still going to have big sound from 11 in wide wheels and low profile tires, they are noise generators.
But my sound lever is noticably quieter than a stock car

slicky rick

Brother what did you use? Dynamat too or those soft blanket like material with the plastic backings similar to the items used behind the rear seats of mercs?

slicky rick

Did you remove the rear seats first and put the linings and then reinstalled? Weight penalty?

RichFL

How do you remove the rear carpet? I might want add some sound proofing.

okbarnett

I put gt3 rear carpet, no seats no holes. You remove the seats , then the carpet section. then put the material over everything you can get to. I have used black butyl rubber and foil lined vinyl, both are the same sort of material and just depends on the one you want. They are about the same price. I got them on ebay. I used about 18 to 22 squares, each are 12x12. I put them on the drive way and get them hot then put them down. you can go under the seats and the front floor, just keep taking the carpet up. They weigh about 5 lbs total, I guess
The theory behind this is not to block the sound. It is to dampen the vibrations of the body which is caused by the vibrations of the engine, road, tires, etc. the only way to block the sound is to wear ear plugs.

RichFL

Got it. Thanks.

dndodd

I took a different route using Dynamat with the foil a strategically places, pieces on the plastic underneath the car and in the wheel wells.

I felt this subdue the resonance between the plastic and the sheet metal I like the difference.

You can tell the difference by just knocking on the plastic before and after material applied

Don't need to add a lot, the car will never be Lexus quiet but it certainly took the edge off for me. Sorry no pics.

See this thread on for my original post;

http://www.6speedonline.com/forums/9...ml#post3427313

RichFL

I picked up the Porsche last week so I'm not thrilled by the idea of tearing the interior apart. The work you did sounds like a great compromise.