Afrosheen

One thing Infiniti owners have done in the past to quiet down road noise is to use foam insulation to fill in the giant empty caverns in the front fenders above the wheels. Some tried styrofoam and other insulators but the kind you spray between surfaces and expands seems to do the best. Those wheel arch body pieces are large and hollow and resonate with road noise. Closed-cell foam can also be used in the doors if there are significant hollow places. One last thing you may try (if your car doesn't have it) is the spray-on bedliner or other undercoating material on the plastic guards inside the wheel wells. I believe the rear wells already have this but the fronts may not.

SW17LS

Wow, cool! Thats something simple enough we all can do it. I too am interested to hear if you put the dynamat on both the plastic liners and the metal.

I'm happy with the sound level of mine, but quieter is better maybe I'lll give this a try...

Howiiieee

Hi folks:
I tried to put Dynamat on both the metal walls and on the back of the plastic liner. The Dynamat stick to the metal very well, but it is having problem sticking to the liners. The liners have felt like surface on the back and a flat white bag with some insulators inside. I put the Dynamat on the front liners (kind of stick to it), but not the back (does not stick well). I think it is as well as it can get.

The spraying foam sound deadener is hard to get, needs professional to work on it, and the result could be marginal. I think the Dynamat in the wheel wells is the most simple and economic way to achieve road noise reduction in any car for most of us.

DaSyce

iTrader: (3)

Suggestion.. Closed cell foam between wheel well liner... Similar to what second skin audio sells.

GregCanada

I know this thread is a bit old, but i have to agree with the other posters, dynamat is NOT meant to block road noise. It is meant to block vibrations. This is what you need to block sound (it's also alot lighter than dynamat) http://store.secondskinaudio.com/luxury-liner-pro/. Sorry to tell you but your audio shop guys are definitely not professionals in this sense.

Here are the stick on coatings they sell http://store.secondskinaudio.com/noi...tion-coatings/ - use this http://store.secondskinaudio.com/spe...udge-1-gallon/ and paint it inside your wheel wells. Nothing is going to stick to your plastic wheel covers as they will move / flex / shrink / get dirty.

Greg

silguy

Aren't our ears decible readers? j/p.. Maybe you should do more research before spending all that money, but if you have plenty of it, so be it. Hurts me just reading that you're disappointed w/ all that money you spent.
I've played w/ auto sound deadening and researched it awhile ago. It's labor intensive and expensive. You'd have to strip everything out is the most expensive part.
The noise that bothers me the most about this car is the window wind noise. Other than that, i think its pretty quiet, honestly. The next thing you could try is spray your whole car w/ sound deadening spray; QuietCar. You can also try to cover your flooring w/ sound deadening mats on top of your dynamat. But the droning noise is the tires and the road, so you have to block that area. Maybe you could try to spray your whole fender area. I don't think it'd make a difference if you got the dynamat on the plastic fender liner. That doesn't make much noise. Its usually the metal vibrating the sound. But since you're doing whatever it takes, do everything then. Good luck w/ the project. I'm subscribed so I can see your results.

Thanks for the pictures.

metrathon

Like others have said, you pretty much wasted time and money. Dynamat is for vibrations only, doesn't do squat to absorb noise. More research would have saved you lots of trouble. Now the car is noisy AND heavier. I went through the same story with one of my 5-series so I know it first hand.

There's no easy solution for sounds insulation. You need a combination of foam for small odd shaped enclosed spaces, and layers of special rubber and vinyl for floors, ceiling, etc. It's huge work, and up to a few thousand dollars, as you basically need to remove everything from inside of the car.

Good luck with your quest.

ISFPOWER

iTrader: (20)

howie wasted money and didnt take my advice. these placebo effects, lol.

dseag2

The only money he didn't waste is on the Michelin Pilot SS tires. I replaced my OEMs with plenty of tread left with Michelins and the car does ride much better and, like he said, feels the best in Sport +. I also find the car handles better.

MTerrence

I thought I'd make an extra post in this thread, because making a car quieter is something that I think has timeless appeal.

In my view, the road noise from the Lexus GS really stands out in comparison to the rest of the car noises, which are impressively well controlled.
As far as I can tell, the conclusion here is that the original poster made an error by using a vibration damping product when he actually needed a noise barrier to block airborne sounds.

I already have pretty good tires (Michelin Primacy MXM4s), but I'd be curious to hear whether there exist any good products for application to the car's wheel wells. All else being equal, I'd rather not take apart the interior.

Is there a practical, easy way to create a sound barrier on the wheel wells and knock the interior noise down a notch? If not, I'll just live with it. (Unlike the OP, I'm not used to a Lexus LS!)

GregCanada seems to be suggesting Spectrum Sludge - is anyone able to vouch for its quality?

EDIT: Derp. There's already a new thread on this topic going on. Sorry, guys.

Byprodrive

iTrader: (1)

[QUOTE=hadokenuh;8155478]The Michelin PSS is quiet among max performance summer tires but still not the quietest Michelin you can get though. The only way is to go with all season high performance or grand touring tires but that kills the purpose of driving a F-Sport.

+ all season tread designs are the most prone to causing noise, especially if they wear unevenly.

Byprodrive

iTrader: (1)

Michelins are as quiet as any tire made & will get quieter as they wear EVENLY. If you allow tires to wear unevenly you have altered the tread design & air moving thru the tread blocks can cause noise.

Beaznuts

Just my .02 cents...

I've had Dynamat on many of my cars and overall the GS doesn't seem live a vehicle that would benefit a lot by adding a bunch of Dynamat. Tires are definitely the root of much of the cabin noise. Taping or securing the window switches helped vibrations a lot from stereo noise but a tire change helps most with road noise.

I have a 2014 RWD with 19K running stock Bridgestones. I'm going to plus size wheels and go with RE750's to address the road noise I get from the stock tires soon.

GregCanada

I haven't used it yet - too many other projects on the go!

I've got their dynamat equivalent, and will install some of their CCF foam when time comes.