I did search, and found lots of comments and information about sound deadening. But, I did not see any specifics on my question that I describe below. And, I respectfully ask that a Forum Moderator does not move this message to a different sub-forum since it’s about sound and CES implementation in the Z.

Background information: I have a 2003 coupe. This model is not unlike a traditional station wagon car where the rear wheel-wells are inside the car. With the rear wheel-wells inside the car, there is significant road noise.

Additional comment: I notice that the Z convertible and the G35/37 coupe do not suffer this noise-issue because the rear wheel-wells in these models are inside the trunk and well-insulated from the car’s interior.

My question: Has anyone placed sound deadening only in the rear cargo space covering the rear floor and the rear wheel wells? If you have done this, how do you rate the result in quieting the road noise?

More information: I am asking this question because I am installing a rearview camera, and this is a good opportunity (since I will be pulling up the carpeting) to place sound deadening if it is any advantage.

Thanks in advance for any comments, advice, or personal experience.

--Spike

 

It will help some, but dont expect it to be like a lexus. I have dynomat, I would say it cut road noise 10-15 percent.

 

I used dynamat extreme. I thought it worked very well but I took everything out of the hatch area and double layered some parts.

 

I just got done doing my Nismo. No it will not ride like a lexus, however it will cut down more than 10-15 percent. I do have some insight on this as i have just done mine that I would be more than happy to help you with. If you would like myy phone number Pm me and I will give it to you, or you can just PM me with yours.... I used Dynamat extreme bulk kit with 36 sq feet. One pack is not enough to do the floor area if you do it right. I would say get 2 packs if that is all you are doing..... I am on my third box and have only done to the seats. Like I said I think i can help you and save you a lot of time and hastle if you would like to talk.

Chris

 

I layed eDead V1 in the entire rear hatch area. Costs less than $1 per square foot. It took me 30 square feet to do the hatch area and rear speaker enclosure.

It only slightly killed the road noise. Much quieter that it was before, but still not to my liking. The common thing to do is lay 2-3 layers of edead V1 in the read to have it make a big difference. Also, my spare tire isn't in the back, so I'm assuming that the empty space under the carpet lets more sound in. Could just be me tho.


If you can get a hold of some... Half inch thick foam bed material works very good as a sound deadener. Sounds lame, but it works very good. It is similar to the material of the contour pillow if you can remember that.

 

Due to the nature of the way sound travels, it's fairly unlikely that you can lower the noise from the tires being in the cabin as much as we'd like. It's possible to lessen the noise, maybe even dramatically, but might take quite a bit of material to get it down to the point of say the convertible, or a standard sedan, where the wheel wells are separated by a closed air space.

Sound loses the most amount of energy when its medium changes. In the coupe the most we can do is add mass to the metal it travels through.

TK

 

I use "GSI dampit". Covered my rear hatch as shown by the pic. Wen i took the car out like dat, there was a diferrence (less noise) compared to without fully applying the sound proof. It made a difference when all the interior panels are put back into place. Road noise to me sounded lesser den before, as others indicated around 10%-15%.

http://i210.photobucket.com/albums/b...00637small.jpg

 

Ooppss cant edit post, here ya go...

 

I used a gallon of edead V3 liquid in the hatch area (probably overkill), as well as layering one to two layers of 1/4" neoprene foam over the V3. After putting all the panels back, I glued two layers of 3/8" foam carpet pad together, cut it to the size of the carpet and placed it underneath.


There is definitely a noticeable difference in sound reduction and I enjoy not being able to hear little pieces of gravel get kicked up into the wheel wells (which always annoyed me before).

 

I used Second Skin's Damplifier Pro in the hatch of my Z. I can't say I noticed much of a difference. The "tings" turned to "ticks" but that was about it.

 

Not sure how much it will help, but you might want to put some material in the areas behind the seats where the bose sub and pass. glovebox go. I noticed when I installed my sub there was a lot of metal exposed in those areas.

 

Thanks guys… very helpful responses. A specific mention is in order to 9292 for taking the time to post a picture.

I would think anything approaching a 20% reduction in road noise and outside noise is significant since that is a noticeable improvement that makes things better.

Some comments:
That (“being able to hear little pieces of gravel get kicked up into the wheel wells”) is very annoying and is something I definitely want to handle with sound deadening. Thanks for your comment.

I notice the same thing you mention. The large pod behind the driver/passenger seats (holding the rear glove box, OEM Bose Subw, and the small upper cubbies) has no sound deadening (i.e., no insulation or carpeting). I think this is an area that allows a lot of road/carriage noise into the car’s interior. In fact, I think Nissan should have addressed this problem in the initial design.

Your comment describes the problem well, and propably the solution. “Piling-on” a bunch of sound deadening cannot do what adding some air-space accomplishes.

And, much thanks for the others responding: zguy3, Bazten1, whitemikecn, Silverstone-Z (great avatar BTW), and DVFlyer. You guys provide very helpful advice.

I hope there are others who want to comment. I'm particularly interested in hearing about sound-insulation in that big pod behind the driver and passenger seat.

--Spike

 

As for the gravel hitting the wheel well... I think I might have come up with a solution.

You know that truck bed liner stuff? That thick, textured black stuff? I've been thinking about picking up a couple cans and lining the exterior part of my wheel wells with it. Instead of the gravel hitting the metal, it'd hit this thick material. Theoretically, it should deaden the sound of it a lot.

 

^^ I agree, but my body-shop source cautions that this could trap moisture and promote rusting.

I’m confused and not sure what to thing here. My instinct is that you propose a good solution.

--Spike

 

It could trap moisture... good point. Forgot about that.