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Discussion Starter #1
here is my situation,

i live in Montreal Canada, and the road on like war zone. I now have 18" rims and damn the it is noisy inside on the highway. I can hear the sound of the wind and the sound of the tires rolling on the road. Now my car is noisier than my sister's civic 2000. (by the way no rattle at all on the civic)

Id applied B-quiet (something like Dynamat, Brown Bread...) the whole trunk and the door panels and still as for the road noise it hasnt much change . Even with 2-3 layers. But i notice the sound quality increased dramatically. The sound of the base is somewhat "firmer".

I heard tha we can put expanding foam like GreatStuff. I saw a member applying Expanding Foam in the trunk between the car body and the trunk panel.

i know they are not specifically made to be used in cars.

Then where else can I apply Expanding Foams on our 6?

What are the Pros and Cons to this?

Thanks in advance!


Ps: please do not tell me that i should have bought a Camry or Accord instead. I have my own reason of choosing the 6.
 

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well.... It will work. but it is messy. You would probably be better off spraying the foam onto something then "painting" it onto the parts you want coated.
 

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Discussion Starter #3
well.... It will work. but it is messy. You would probably be better off spraying the foam onto something then "painting" it onto the parts you want coated.
[/b]

I wont be messy, I wouldnt apply that where we can see it, but rather places that are hidden. For example, between the car panel and the black fabric/plastic/or dont know what in the trunks.

I was thinking more about places with cavity, and fill those cavity.
 

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I bet you could cut down road noise, get some performance, and get a smooth ride if you went with a smaller rim.
 

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Discussion Starter #5
true true, but i like 18'' better!

stock tires were 215/50/17

my new tires are 225/45/18, there isnt that much of a difference. probably the tires are more aggresive
 

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Did you apply anything to the floor boards under the carpet... I saw a post not to long ago where someone had their interior out and it looked like there was damn near no sound deadening before they put down some. Not sure if they removed before putting more on. But I believe I saw them say it was a LOT better afterwards.
 

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Check this post. He is giving you a textbook example of removing road noise.
 

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Discussion Starter #9
Check this post. He is giving you a textbook example of removing road noise.
[/b]

yes i saw that post, but i dont have the courage to take everything off...
 

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Most road noise comes from the roof believe it or not. The wind makes much more noise over the roof then you think. The floor would be the firewall would be the next source of noise followed by the floor.

As far as tire noise, there really is no solution to that other than get new tires.
 

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Yeah, if you don't do your floor forget about getting rid of the majority of the road noise especially in the fender area. My floors are completely covered and I still hear a good deal of noise, although I have a lot more to cover and I'm missing my carpet, panels, and everything else. I'd say the road noise decreased by about 50% with just the floor dynamatted.

The floor on our cars are just bare metal, the only thing that provides any type of sound deadening is a foam that is on the bottom side of the carpet. That foam doesnt even cover everything, it is only in certain places.
 

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Yeah, if you don't do your floor forget about getting rid of the majority of the road noise especially in the fender area. My floors are completely covered and I still hear a good deal of noise, although I have a lot more to cover and I'm missing my carpet, panels, and everything else. I'd say the road noise decreased by about 50% with just the floor dynamatted.

The floor on our cars are just bare metal, the only thing that provides any type of sound deadening is a foam that is on the bottom side of the carpet. That foam doesnt even cover everything, it is only in certain places.
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Dynamat FTW, used it for 4 years and never thought it didn't work for road noise or sound dampener. My 97 Explorer had Dynamat on the flooring but none in the roof. ROad noise went down to I'd say 35%-40%. I know most sound dampeners are the same, just letting you know Dynamat actually works. You might want to try looking into tires if there are no other options, just deal with the ones now then in a bit buy new ones, like say after winter into summer when you'll actually be able to use them.
 

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Discussion Starter #13
oh well, i dont drive that much now that i am in University. It is downtown and it is too much of a hassle to find a cheap parking, traffic, gas.... i just take the bus and metro.

last summer i dynamated under the backseats, the trunk and 2 doors... i will try the roof next summer and the expanding foams.

is there a how to on removing the roof interior???
 

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If you do use GreatStuff, make sure you wear gloves, or you'll be pealing it off your hands for DAYS afterwards.

Also, keep in mind that it sticks to EVERYTHING, and can be a real bitch to deal with and clean up.

Good luck!
 

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you said you noticed the road noise after you put on your wheels, so, i can bet money its the tires that you have on there. you might try getting different tires. what tire do you have on there (brand and model)? i've experienced loud road noise on Dunlops and Nittos Neo Gen
 

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If you do use Great Stuff make sure you use the blue can with the yellow top. It is low density, soft, foam. I've used this on several cars now and it works awesome. If you use the black or the red can you are going to have a mess and it expands. When it expands it can actually crack your interior. The best solution that I've found was to dynamat the outside skin of the car and any major interior flat supporting sections, then use the blue Great Stuff to fill in voids. Just remember, if you fill an area with foam and you need to get in there it's a pain. Be careful with the doors as you need to allow for the window glass and tracking. All of that said you will notice a HUGE difference. Road noise is lower, your stereo will sound allot clearer as it's not competing with your tires, and another side benefit, your car will heat/cool allot better. If you are going to go through the trouble of foaming another anti noise solution is to dynamat the floor of the car. It's allot of dynamat but even if you just do under the mat of the front seats you will be removing allot of engine/wind noise. Hope this helps.
 

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Discussion Starter #18
If you do use Great Stuff make sure you use the blue can with the yellow top. It is low density, soft, foam. I've used this on several cars now and it works awesome. If you use the black or the red can you are going to have a mess and it expands. When it expands it can actually crack your interior. The best solution that I've found was to dynamat the outside skin of the car and any major interior flat supporting sections, then use the blue Great Stuff to fill in voids. Just remember, if you fill an area with foam and you need to get in there it's a pain. Be careful with the doors as you need to allow for the window glass and tracking. All of that said you will notice a HUGE difference. Road noise is lower, your stereo will sound allot clearer as it's not competing with your tires, and another side benefit, your car will heat/cool allot better. If you are going to go through the trouble of foaming another anti noise solution is to dynamat the floor of the car. It's allot of dynamat but even if you just do under the mat of the front seats you will be removing allot of engine/wind noise. Hope this helps.[/b]

i already dynamated the rear floor of the car. I noticed that there is a lot of noise coming from the the trunk (when the back seats are folded). I dynamated alreaty the whole trunk!

What i'll do this spring is put foam in the back seats, then dynamat it. also put foam in the rear fender of the car (between the outter panel and the trunk)

I will use the blue can with the yellow top, thanks for the advise!



you said you noticed the road noise after you put on your wheels, so, i can bet money its the tires that you have on there. you might try getting different tires. what tire do you have on there (brand and model)? i've experienced loud road noise on Dunlops and Nittos Neo Gen[/b]
i have the stock RX-8 tires. Bridgestone something. they are 225/45/18.

shitty tires, after 10,000 miles they are all worn off, road noise is unbelieveble.
 

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Discussion Starter #20
do realize that the foam over time will deteriorate leaving grainy mess[/b]

oh ya? even if put in hidden areas?
i have no intention to put in the door though.
 
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