SurfDog's Soundproffing journey
 

I Couldn't take the noise. I want to LOVE my Z, but the Friggin' road noise is killing me!!!

So... Dynamat!

Here are some Photos.
This one is about 1/3 the way into Dyna-carpeting my Hatch.
Nissan 370Z Forum - SurfDog's Album: Surfdog 09 370z sport - Picture

Here is the trim I pulled to get access.
http://www.the370z.com/members/surfd...-out-trim.html

Pulling the trim seemed a bit intimidating, but I spoke with my dealer service manager and he gave me some tips and advice (it was actually pretty easy)

Anyhow the results are noticeable but NOT A HOME RUN:icon14:

I have ordered a 10 square foot FREE SAMPLE of GT Mat from Pintsized725. I will put it on the Doors as soon as I can find some time. I suspect 10 feet will *probably* only cover 1 door. We'll see.

My plan looks like this:
1. Dynamat hatch: done- result: noise is better, but not better enough.
2. GT Mat doors:Materials on order. Results-TBD
3. GT MAT or Dynamat Wheel Wells. Results-TBD
4. install quieter non-stock tires: I'll wait till my tread gives out: Results-TBD
5. Consider active noise cancelling sound system in cabin: Results-TBD

I'm looking for suggestions. So far my results have been a bit underwhelming.

The photo doesn't show it; I forgot to snap a "job done" photo (because I was beat), but I Dynamatted every inch I could reach of that Hatch and up into the left fender as far as I could reach. It improved, but DID NOT solve the problem.

If anybody has really nailed this problem down and can help me with "best bang for the buck" suggestions, please chime in. I don't need the Z to be silent, just pleasant to drive on longer trips.:driving:

I'm certainly no expert at sound deadening, but I've tackled projects like this on previous cars - in a similar manner. I think the primary reason you didn't get the results you were looking for (nor did I on my previous cars) is that you really need to take a three-layer approach as outlined here:

http://www.sounddeadenershowdown.com/cgi-bin/index.cgi

The layers, from the bottom up, should be a 1) dampener, such as Dynamat or even Frost King from Lowes, 2) a closed-cell foam and 3) mass loaded vinyl on top.

Dampener materials don't have the necessary mass to knock out much sound, they only dampen vibrating panels (still important, though). Ideally, you'd want to use lead for its optimum sound reduction, but it's restrictively heavy and difficult to use...hence the mass loaded vinyl as a substitute.

Most of the big name products out there that people tend to use fall more under the 'dampener' category, and don't have the acoustic suppression properties people are looking for.

I'd recommend getting a digital sound level meter (Radio Shack has one for around $50) to measure sound levels on some test roads at set speeds to monitor results.

Just my two cents, though, is that I'm shocked at how refined the Z is. It measures about the same dB levels as my daily driver ('08 Mazda3) and really only exceeds it on horribly rough pavement. I was sure that I'd be looking into a project like this once I got my Z, but after a month of ownership I don't think I will - that shouldn't detract from what you're trying to do here, though. Good luck.


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We were just talking about some of this Here http://www.the370z.com/audio-video/6...o-install.html

You need foam instead of a mat layer.

Hushmat or dynaliner

Dynaliner

Thanks! I'll look into it!

I plan to stop all the panels I can reach from ringing with Dynamat. And I will definitely layer the hatch.

The Z is new to me with used stock tires. I suspect new tires are needed. I think this might help a lot as most of my complaint comes from rough pavement noise.

There are liquid solutions as well, that are much more.... permanent

How is this going? OP, have you made any progress? I'm pondering sound deadening options for the new Nismo and am very curious about your findings.

I agree with you Rockhound, I too followed the noise threads on here for months before buying my car and was prepared to do some sound deadening. After having the car for awhile it doesn't seem to be an issue for me. I think the quality of road surface probably has a lot to do with it. The stock tires also have a low rating for road noise.
I may do the doors as some have indicated it marginally improves front speaker audio quality.

The hatch dynamat helped. Doors next. I think it will be done then though I will definitely not go stock on next tyres.

Definitely worth the effort and 200 bucks to do hatch.

Have you considered using any closed-cell foam or mass loaded vinyl for true noise suppression? Some companies make a combined product that has both materials bonded into one sheet. Cutting one to size for the floor of the rear hatch would likely have a huge impact - just a thought.

Here's an example:
Mass Loaded Vinyl 48W w/Closed Cell (per foot)-Super Soundproofing Store

I have, but I'm worried that I will have to trim my foam "inserts". (That grey styrofoam stuff that goes around the spare) in order to fit them on top of the presumably thick extra layer. My trim already got a bit snug after dynamat.

I do not really care about cutting the stuff, but this is my city car (not my Colorado car) so I don't have much in the way of a garage and tools to modify my foamies.

I might use a mass loaded foam barrier like dynaliner on the doors though.