Roadster Interior Noise Reduction
 

I was unhappy with the road noise at high speeds in my roadster. I did searches in the forum and couldn't find where anyone with a roadster had attempted to reduce the road noise level. Tons of posts about coupes with detailed descriptions and photos but no roadster. After reading them all and confering with Guard Dog, I did a modified version of the coupe sound control on my car today.

Before any of you comment about turn the stereo up or buy a Borla CBE, I like engine noise and the car has a Stillen CBE system but I found the roar of the road a little annoying at high speeds and it made it difficult to have a conversation at normal speaking levels.

Today I installed dynamat extreme over all of the metal surfaces of the trunk floor and walls, exposed fender wells in the trunk and trunk lid. After installing the dynamat I stuffed the voids with poly batting and reinstalled the upholstry.

Next I put a layer of dynamat on the rear fender wells that are under the boot in the interior. It was very easy to do. Just open the top to about half way and lift the pleather material that covers the top motors and wiring and you can access the fender wells.

I then removed the door panels and intalled dynamat on the metal surfaces of the door. This was a rather difficult job when doing it for the first time because someone had to hold the door panel while the install was being done. The side airbag has an electrical connector that was a little scary looking and I didn't want to risk blowing the bags so I left it alone and just had my son hold the panel.

While I had the door panels off I replaced the Bose speakers with a set of Alpine two ways and replaced the door panels.

After a test drive, I was pleased with the results. The overall noise level was substantially down. I would estimate the decrease at about 30%. You still get a lot of the high frequency pings from rocks and debris coming off the tires and hitting the fender wells but they are much less anoying than with the dynamat. The low frequency drone sound is all but gone. I plan on putting on a set of Michelin Pilots when I wear out the OEM Stones and that should help even more.

I would recomend the install to anyone who is interested in a quieter interior sound level. I used six sheets of dynamat and it took my son and I about four hours to complete the project.

The new speakers sound great too. The midrange and upper ranges are much clearer and crisper than with the paper cone Bose models. The Alpines I installed are power hogs and the stock Bose stereo drives the small speakers in the dash pretty hard. It makes for an interesting sound quality that I am happy with. There is still not much base but that will not change unless you put an amp and a subwoofer in the trunk. Driving base is not that important or desirable to me so I will probably leave the stereo system alone for now.

:pics: please.

Glad to hear of your positive results.

Sorry, I didn't take any pics but can answer any questions you might have.

Which dynamat product did you use? How much did it cost?

Dynamat extreme. Got it on Amazon for $120 a box if I recall. It took about 3/4 of a box.

Hello everybody, new member here, European partially living in Mexico !

First of all my apologies for going straight to my question without presenting myself, but I'm quite in a hurry, planning a trip to South Mexico this weekend, and soon another trip to Europe.

I have the opportunity to buy a new 370Z Roadster at a very good price, but I don't have the possibility to see it (the car is in Belgium). Here in Mexico I have never seen a 370Z, and I think that the Roadster is not even sold. It would be for daily use, 2 or 3 month a year when I'm in Europe (tourism/business). I have to decide quickly since there is only one in stock (there is a coupe too).

I have seen complain about the overall noise level of the 370Z coupe and roadster. I have seen that this problem can be solved with Dynamat or similar, and this is not a problem for me to perform such installation.

My question is about the soft top. Is it better/sticker than the one of the 350Z ? A friend who drove the 370Z told me that it is the level of a BMW Z3, which is bad for a 2009 model.

How would you rate its acoustic and thermal insulation ?

SonnyC> now that you have Dynamat all your Z, is the noise coming from the top acceptable ?

Thanks a lot in advance, this forum is very nice, and maybe I will be soon an active member :-)

I don't own a 370z yet, but I went and test drove the coupe today and sat in the roadster. The top is very nice and although I never owned a Z3 I did own a Z4 for several years and the top on the 370z is just as good as the Z4 (at least from what I saw). The Z3 top, which I've only seen a few times is not even in the same ballpark. Of course, I can't speak to road noise as I just drove the coupe.

Most convertibles have terrible blind spots when the top is up, but none when the top is down. Not the 370z though, it sucked up or down, something to consider.

Noise
 

The noise was not really unacceptable before. It is better with the dynamat but I don't know that it was worth the work. The roadster is a very fun car and is a pleasure to drive. I think you would be very happy tooling around Europe in it.

OK thanks for your answers guys !
I will leave tomorrow for a 2 weeks trip in south Mexico. Then if the car is still for sale when I return, maybe cheaper than today, I will contact the vendor.

It's a black/black with 19inches, Navi, etc...

Just finished my doors...had done my trunk a few weeks ago. Still have to pull off the rear wheels and remove the wheel well liner and GTMat the wheel wells.

Hopefully that will get rid of the rocks noise and then i'll be good to go until I wear out these OEM tires.

I might - just might - have my custom guys pull out the seats and do the entire interior. But that's not a priority.

How much weight does it add to the car??

Interior, doors & firewall are probable the most important places to reduce noise.. At least that's what I would do.... My 2 cents :tiphat:

By interior I'm assuming you mean under the seats, behind the seats, and then the firewall under the pedals. I did the wheels wells on my G35S sedan and it made a noticeable difference.

It adds about 15-20 pounds for the entire interior.