Foam in airbox

Any of you guys take the foam located in the airbox under the filter to make the car sound louder? I've heard that you can take the foam out to give your car a little more roar but will this have any affect on the performance?

there is no foam in my airbox.

LOL..I thought so too but somebody I know personally did this and he told me that he took the foam or whatever out under the filter, now his car sounds a bit louder. Im going to check and take some pics to post. I also thought to myself this must be the dumbest post that I've ever posted.

No clue what you are talking about, really...but I'll give you my opinion anyway If there's foam in there, don't you think it may be additional filtering?

Not in any of my 3 PCars...............

If by foam you mean the foam that spilled out of your beer...yes it should be removed. There is no foam in the airbox...LOL.

In my '02 there is some "foam" in the airbox. This "foam" is in front of the drain slits for the air intake. I assume this is to allow the water out but keep anything from entering through the drain. I don't know about any performance increase, but if everything else is stock it might seem to be slightly louder with it removed. Imo..I would leave it in, I recently found a couple of mice that had some how found their way into my intake, so for me the fewer holes the better.

it's good way to get something you don't want in your engine in there.. leave any filtering/blockades on there.. not worth the risk.. if you want a loud car, get the fabspeed bypass for $400..

This is located in the airbox, under the air filter and is a baffle to reduce sound It's a sponge type material held in with a plactic bracket and 6 phillips head screws. Makes a minimal but noticable difference in sound, not performance.

This mod reminds me of the people drilling holes in their 964's airbox for extra sound. Simple yet effective if one is looking for more roar in your 996. Thanks for the pic Vulture.

That looks very interesting. I may have to tool around over the weekend and check it out. Of course, if Porsche had really wanted some proper dampening, I'm surprised that they didn't go with Dynamat or a more proven product. Foam? Hrmph. I have no response for that.

I'm close with the crew over at TPC. This is one of their suggestions. I did it, sounds a little better.

Is that the "airbox muffler" that gets deleted when you get a Fabspeed or Schnell intake mod kit?

OK, I found this thread which sort of answers my previous question...it appears to be for noise. Appears different years don't have it..(mine is an 02 C2) There is a small, maybe 1/4" drain hole under it, not enough to worry about mice, for sure. While searching , I found lots of references to the airbox being sealed. In mine the right rearward quadrant has maybe 60 small maybe 1/8" holes drilled in (factory drilled, not owner) so it is most defnitely NOT sealed...anyone know when this occured or why?

Haven't seen any newer threads on this. Based on this thread and one in Renntech, I'm just going to remove the foam in my airbox. Mine's really brittle and I'd rather not have it circulating.I can't find the specific part number just for the foam. It's the foam in the upper half of the box. Popular vote is that it just dampens sound. Any one have any updates on what this foam does and whether or not it's important?

Sound deadening.

Thanks. I have a cab so that's kind of pointless. Out it goes!

I removed mine on my '02 with no ill effects (didn't expect any). They just fall apart after 15yrs.

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Yes! That, or pay $6 for a GUARDS RED resonator plug & $28 for a silicon hose.

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Where? I want to remove the resonator but cannot find a custom fix to block the hole. The resonator neck sticks through the hole.

its a Helmholtz Resonator and shapes sound waves almost like a speaker trumpet. I replaced my old foam with new similar foam.

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This design, though I forget the exact diameter that fits. Mine is a tight fit but after a few twists it stays put. Apparently, they come in Speed Yellow too cap: https://www.homedepot.com/p/Gripper-...FYW8dwodbiICVA silicon hose: https://www.ebay.com/i/152402030748?chn=ps&dispItem=1

Well, I got no input other than to say we need to see more of Russ Murphy around here.

New guy here. Reviving an old thread, as this is the only information I could find anywhere about this foam. Mine is also degraded to the point that it just crushes down and falls apart. You can see in the photos below, that this foam does not cover any holes (theorized to keep bugs out). It sits at the bottom of the lower half of the air box and not having a weep hole there makes no sense to me. I�d love to replace it just for the sake of having it refreshed. Has anyone here, since this thread died, been able to figure out what it�s really for and if there is a replacement?

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I am guessing it absorbs any moisture that enters the box from the side intake. My box has a few very small holes under to allow drainage? I am replacing mine with sponge washcloths since Porsche parts can�t find it listed anywhere. In fact they said I had to order a new box to see if it was included 🧐

The perforations and foam are just for "acoustics", to get a certain sound from the intake system noise ... a tuning device... The air box does need enough holes for water drainage in case of a torrential down-pour......you certainly don't want to ingest water into the engine, a hydro-lock would occur .. I have seen some engines hydro-lock due to water ingestion from a poorly designed air intake system....The Ranger comes to mind, if you try to forge a flooded street with about 18 inches of water, the engine will gulp water and hyrdo-lock due to the location of the intake air ducts...

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where to you get the foam used to replace that �stuff� that fell apart in the bottom of the air box?

Foam was degraded to dust in mine so I removed it and I covered most of the holes. There are holes left to drain water if needed, but normally not driven in rain. Also, I collected several air boxes from junked 996s and they all have different hole configurations.

Yep, all the different hole configurations make a slightly different intake sound... On the 986 Boxsters there are 5 different intake pipes from throttle body to air box in 5 different degrees of Helmholz resonators. One has 2 , one has 1, one has a smaller one, and one has none...The one with none is the loudest and was used on the 2004 Spyder Aniversary Edition..

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I found this on Amazon and am going to try retro it to my airbox. https://a.co/d/635j3VA

I was looking for the same thing after I removed my airbox today - so that link is very helpful. The foam was falling apart and moldy. You can see from the image that it seems to be used for a moisture absorber or trap - did nothing to stop leaves from getting in though . Some of the screws holding down the 'foam cage were also rusty that will need to be replaced.

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Same. @43rdworld did you get new screws? If so do you happen to have the specs? Thanks

Did you closed the Resonator?

I haven�t yet but I plan to. I�d still like to have the airbox clean and change the screws and the foam if it�s best to keep the box closed to some extent regardless of noise

I never did find the OEM part numbers. Wound up getting some off of Accu - 4/10 Pozi Flanged Screws in black stainless https://accu-components.com/us/plast...ng=1&c=2&gQT=1 If I recall, they were a touch larger, but worked just fine.

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Thanks for the reply @43rdworld . Yeah I couldn't find the part number either, the screws are not on the diagram on the parts catalog unfortunately. When you say a touch larger, do you mean the thread?

Its to absorb moisture in the airbox, holding it /absorbing it so it has time to evaporate gradually and work through the intake as opposed to having a puddle sloshing around ie after you wash car and water gets in.