# Foam filled A/B pillar



## backotruck (Jul 18, 2008)

Hey all, 

I am considering foam injecting my 98 Accord with foam in the A/B pillars. Good idea? No? There are already factory holes in the A's, so any foam that spills out I would just let dry and razor off flush. Any experience with this? Would it quiet my car? I have treated inner et outer door skins, and nothing else as far as treatment.

Thanks fellas,
backotruck


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## falkenbd (Aug 16, 2008)

what would this accomplish for you?

You can probably accomplish the same thing with a different product...


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## Trade-n-games (Nov 25, 2008)

My take on something like this is that since it is hollow and does not get wet there I would just stuff it with closed cell pad and that would help a little. If you were to get a ding/dent on the piller then it could be removed out for PDR. I hate door digs and when people fill all those spot in trunks and such the PDR tools can not get in there and then bondo and repaint is the only thing you can do.
second thing is I have had a few cars very layered up and then i could hear all the sound coming in threw the glass.


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

A/B pillars, prolly not worth it, they are small and well folded (for stiffness) but the rockers, that might be something to look at... 

I've done mine, along with various other areas... can I tell a difference, no, does it give me some sort of piece of mind, sure, I did the work...lol...

you can search out my "foaming fun" if you like, lots of pics..


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## backotruck (Jul 18, 2008)

This would be done from the inside, I forgot to mention. I took off the plastic molding and saw the bare painted metal when I was sitting in my driver's seat...I thought "Couldn't hurt to just fill that in with foam" It my quiet it down a little....Who knows...I have to wait until it warms up a bit anyway.


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## basicxj (Jan 1, 2008)

I was running some wiring down the a-pillers in my '98 Cherokee, and was surprised to see they'd filled the pillers with an expanding foam material at the factory and ran the OEM wiring below and outside the natural channel of the piller so fits under the trim...I had less room in there than I thought I might. Can't say the OEM work hass done a huge amount of good in this case- the factory used some closed cell foam under vinyl barrier on the firewall, foam in the pillers, undercoating and a Dynamat-like product on parts of the floorpan, yet the car still peaks around 90 db from road noise alone inside . 

Your results may vary.


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## gijoe (Mar 25, 2008)

Aaron'z 2.5RS/WRX said:


> A/B pillars, prolly not worth it, they are small and well folded (for stiffness) but the rockers, that might be something to look at...
> 
> I've done mine, along with various other areas... can I tell a difference, no, does it give me some sort of piece of mind, sure, I did the work...lol...
> 
> you can search out my "foaming fun" if you like, lots of pics..


I'd have to agree with this one. I'm not sure it'll make much difference, but I do little things like that for peace of mind. I guess somewhere in my mind I justify hours of work based on the theory that 'it can't hurt'


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## GlasSman (Nov 14, 2006)

Unless theres wind noise entering the cabin through those holes...I doubt it'll make a marked improvement.....but it's can't hurt...

......well unless you _*hurt *_yourself while you're doing it.....


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## tspence73 (Oct 14, 2008)

It's my opinion that every little bit to deaden/insulate the car/vehicle will do 'something' to help reduce the overall noise in the cabin. If you keep plugging away, taking out one problem area after another, it will eventually start helping. Sometimes you might have to double up on some insulating material in certain places. 

I especially intend on taking care of the body panels with VE damper on the front of the car or maybe use luxury liner on the body panels of the car where wind and other noises first start while driving. The firewall will be another spot to double up efforts on. Most of the noise while driving I figure would have to come from where the air meets the car. Hood, front quarter panels, *A-pillars*, roof, front doors and the engine noise comes through the fire wall, including wind noise. The floor of the car is also exposed to wind noise. The wheel wells of the car pick up major noise from the tires. It's easy to understand how this cabin noise in cumulative over a lot of surface area. You can't really treat the glass of the car (AFAIK) but you can treat everything else.

If all these areas get attention, I would have to think you'll get a big improvement in quietness.


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## capnxtreme (Feb 5, 2008)

tspence73 said:


> Most of the noise while driving I figure would have to come from where the air meets the car.


Why are you talking?


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## tspence73 (Oct 14, 2008)

capnxtreme said:


> Why are you talking?


Why do you have to be a jizz catcher?


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## FoxPro5 (Feb 14, 2006)

Before the impending derailment....

Is it really worth the time, money, energy...not to mention the complete mess...by adding a closed cell foam that doesn't absorb noise to panels that sound can easily refract around to achieve a 5% gain?

Road noise experiment: get on the highway after a fresh, clean snow and kill the engine for a few seconds. How loud is it inside your car?


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## falkenbd (Aug 16, 2008)

FoxPro5 said:


> Before the impending derailment....
> 
> Is it really worth the time, money, energy...not to mention the complete mess...by adding a closed cell foam that doesn't absorb noise to panels that sound can easily refract around to achieve a 5% gain?
> 
> Road noise experiment: get on the highway after a fresh, clean snow and kill the engine for a few seconds. How loud is it inside your car?


Just make sure you won't need your brakes or steering during those few seconds... [straight, flat spot with now traffic]


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## DaleCarter (Jan 3, 2008)

basicxj said:


> I was running some wiring down the a-pillers in my '98 Cherokee, .... yet the car still peaks around 90 db from road noise alone inside .
> 
> Your results may vary.



Your results may vary, especially if you don't drive a 10 year old Jeep!!

j/k, I loved my old Cherokee but DAMN they are loud.


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## Jimi77 (Jul 4, 2005)

DaleCarter said:


> Your results may vary, especially if you don't drive a 10 year old Jeep!!
> 
> j/k, I loved my old Cherokee but DAMN they are loud.



I know what you mean... the K&N intake and aftermarket exhaust aren't helping either.


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## Cdub78VA (Jan 4, 2009)

My bro has an old cherokee...pretty loud.


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## backotruck (Jul 18, 2008)

FoxPro5 said:


> Before the impending derailment....
> 
> Is it really worth the time, money, energy...not to mention the complete mess...by adding a closed cell foam that doesn't absorb noise to panels that sound can easily refract around to achieve a 5% gain?
> 
> Road noise experiment: get on the highway after a fresh, clean snow and kill the engine for a few seconds. How loud is it inside your car?


Wouldn't a 5% reduction from 70 be around 66.5? I don't think it would be very complicated to just spray and wait...BTW, I'm talking about INSIDE of the metal of the frame, not between the plastic and the frame...


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## bobduch (Jul 22, 2005)

Your not going to get 5% from 2% of the area of the car. 
I would use a fibreglass (I used Owens Corning Black Acoustic Blanket) type product on cloth so that no fibers are floating around. Absorbs move sound than foam. Also between plastic and metal. No you probably won't hear the difference. But do enough of these areas and eventually you'll gain some small benefit. 
The snow example is good. Same with fresh tar pavement. I get a 7db reduction in noise level at 70mph between fresh tar and concrete on the highway. Some of the firewall noise problem is the air intake for the heater. Noise comes right through it. 
A hoodliner is also helpful. I use Scosche AMT750 under the liner in my Honda van.
I also sprayed rubberized undercoating on the outside of my wheel wells. That helped a bit.


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## FoxPro5 (Feb 14, 2006)

backotruck said:


> Wouldn't a 5% reduction from 70 be around 66.5? I don't think it would be very complicated to just spray and wait...BTW, I'm talking about INSIDE of the metal of the frame, not between the plastic and the frame...


Have you ever used expandable foam before?

I just re-read your first post and you never said what your objective was in doing this. You asked if it will quiet your car and the answer is: not that you will be able to tell. Noise will just refract right around the pillars and go through the glass. It would be like filling every 3 ft or so of a wall with foam hoping to get a noise reduction across it. It's not going to happen as the noise will just take another route (ie the spaces you didn't treat). 

Closed cell foam is a good thermal product and that's why Great Stuff is used as a weather seals around doors and windows. Can it be much of a thermal benefit in a car? I guess anything is possible.

If you took an hollow steel pipe and filled it with expandable foam, it would probably resonate less and "feel" more solid. That's about all you can hope for by doing something like this IMHO. I know there's a similar product that race cars use in their rails to help reduce roll and stabilize the frame and such.


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

FoxPro5 said:


> If you took an hollow steel pipe and filled it with expandable foam, it would probably resonate less and "feel" more solid. That's about all you can hope for by doing something like this IMHO. I know there's a similar product that race cars use in their rails to help reduce roll and stabilize the frame and such.


That's just about my conclusion from me foaming my rockers... I wasn't expecting much, but, it's something i've wanted to do for years, and I got the chance, so I did it... 

I got more benifit from using overkill on the interior in terms of reducing the echo inside the car (sans interior at the time)


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## backotruck (Jul 18, 2008)

FoxPro5 said:


> Have you ever used expandable foam before?
> 
> I just re-read your first post and you never said what your objective was in doing this. You asked if it will quiet your car and the answer is: not that you will be able to tell. Noise will just refract right around the pillars and go through the glass. It would be like filling every 3 ft or so of a wall with foam hoping to get a noise reduction across it. It's not going to happen as the noise will just take another route (ie the spaces you didn't treat).
> 
> ...


I agree. Think I'll just stick to wheel well, and luxury liner.


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## dirthog (Jun 21, 2007)

Every time I've used expanding foam it hasn't helped. It actually created a squeak cause by it rubbing on metal or plastic.

I don't recommend expanding foam. 

As for closed cell foam or something like it, I say why not. If you have some left over and it's easy to install go for it.


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