After recently picking up a 997 (non-cab) I find the interior to be awfully loud during driving... between tire / engine noise especially when you get up to freeway speeds. I thought I would get 'used' to it by now but even on the shortest of drives it seems to induce a migraine. In order to hear music its almost like I have to 'overpower' the tire noise and starts to sound like I am at a rock concert. At times it does not bother me...but for most other drives I would prefer to have less 'noise'. The car is bone stock with low mileage - so it is not something that was tacked on previously impacting this.

I tried to address the issue by switching out older pirelli tires for 'supposedly' quieter Hankook V12s - but it did not create any noticeable difference

Now I love everything else regarding the car - just not the interior drone / tire noise it produces - and I understand inherently by design it will have more noise then many other cars.

Has anybody effectively mitigated and addressed that issue with the use of sound deadening materials? Did you do it yourself or take it to a shop (audio store)? And if you got this done how much did it cost you or effort involved? I have tried searching various forums / threads regarding 997 sound deadening and have not came away with any definite answers or how tos. Other 'sports/low insulated' cars seem to a much broader knowledge base of responses addressing this issue (lotus, gt-rs etc) but I cannot find much on the 997!

I would prefer not to rip out the interior - but would like to know how far I have to go in order to produce a 'noticeable' effect - AND if it is even achievable of getting decent results. Im not expecting 'lexus' like sound inside the car but do believe that a change can be possible to take the edge of to make it more daily useable.

 

What are your tire pressures? Seems lots of people here overinflate them, as does my dealer when I forget to tell them to not adjust my pressures. More (over)pressure, more noise.

 

Dynamat is very effective, but will require some interior and carpet removal.

 

If you think the 997 is loud you should have driven the English sports cars of the 60s and 70s! It's a "sports car"!!

If you want wuiet get a Mercedes!

Tom

 

Another Issue use Porsche approved Motul or Castrol oil versus Mobil 1. Myself and others have noticed a reduction in mechanical engine noise with this simple change.

 

sound deadening material helps alot, you have to take out thr rear carpet and line the seat pan, even up the seat back and wheel well. Every bit you can do helps that much more. It wont make the car silent but I would say it kills it 50%

 

I almost traded my 997 GTS because of the excessive road noise when on the highways around Dallas...but then I came to my senses. I put new Michelins on a couple of months ago, and that made a dramatic difference from the Pirellis, but that's because the Pirellis were running pretty thin on tread. The car is just fine on normal city streets, but as soon as I get to the longish highway drives, it becomes an exercise in futility to try to listen to the stereo, BT phone call, engine, exhaust, or even passenger. I know the car wasn't designed or meant to be the most serene of environments, but it should be better.

While the 991 is a dramatic improvement on the interior experience, I'm not going to consider one until at least the .2 redesigns come around (maybe with some of the Sport Turismo cues).

I did have someone mention the Dynamat product a few weeks ago, but haven't thought much of it until seeing this post again. Would like to hear feedback or insights to such a project. It appears as though it can be a weekend DIY type of thing. Disconnect the battery. Remove the seats and carpets. Center Console removal??? Cut and apply the sheets. Reinstall everything.

Sound about right?

But what sections of the car would get it? Floor pan (front and rear?). Rear bulkhead and side sections?

SocialPro: Good topic...thanks for posting. I'm interested in hearing more.

 

I would check to see if any of your wheels have bends. The easiest way to see if you have a potential wheel problem is to look at the number of weights on each rim. Also double checking your tire pressure may help.

I just switched from my summers (pirelli rosso's) to my winters Hankook V12's and noticed a big change in tire noise (for the better). My plan is to switch my Pirelli's to Michelin PS2's after this season.

 

Low profile/performance tires are the 'usual suspect' relating to 'road noise'. From my experience Michelins tend to be a bit quieter than their competitors.

Hitting those 'anti aquaplane' sections on LA freeways or off ramps can damage your hearing.

I solve the problem almost daily by turning up the volume on my audio.

How about some ear plugs?

 

It is definitely not the wheels as I just mounted a new set with a new set of Hankooks. I had the same tire on my 335 and it produced a big difference on that when I switched old tires out - but not so much on the 997...hardly can tell a difference from the worn Pzeros that I had.

Earplugs / turning up the volume on the radio is not the solution that I am looking for - I just want more silent interior with a bit of an exhaust growl. It sounds like dynamat / hushmat is the route to go - I am interested in hearing from members that have gone that route and can talk about their experience in getting it done (price / effort ) involved as well as results achieved. I am surprised that not more members here have looked into this as a somewhat 'refined' (were not even talking GT2 / GT3) level of sportscar feels like it should of had a better sound barrier for 100K+ pricetag.

And no - Mercedes / Audi / Lexus etc are not the route I want to go --- yes I understand they are quieter but do not have the 'feel' I am looking for. I would imagine it would be much harder to give a car the 'porsche' feel vs. trying to eliminate some extra tire noise that is why Im looking for a workable (potentially a DIY) solution.

 

I have ZERO complaints of interior/road/tire noise. A poll would be interesting. I added an x-pipe because the whole package was far too quiet.

 

I put up a thread like this previously and no one seemed to offer a solution. But now okb's reply seem to offer an option. 50% reduction is good. I just wonder if there is a lighter option im sure that that much dynamat must weight a lot.

 

Care to elaborate okb on your exercise? Im sure it helped and 50% is tremendous but did it also kill exhaust and intake noise? Did it rduce the sports car feel. Im inclined to believe the 991 went this route and so needed the symposer to put back some engine noise minus the tire rolling noise.

 

Do you have more detail on what you did (i.e. amount of material used, time/effort involved, costs, issues etc.)? Did you do anything up front - carpet, doors, roof?

 

The mbenzes iv had had this carpet like material lining the back where the wheel wells where at. I woukd think this is lighter but do not know ifmit would provide the same sound deadening as the dynamat. Hope othes would chime in on this thread.