Firewall Insulation

Real tech discussion on design, fabrication, testing, development of custom or adapted parts for Pontiac Fieros. Not questions about the power a CAI will give.

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CaptainHindsight
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Firewall Insulation

Post by CaptainHindsight »

What are you using for new firewall insulation? I had to remove it all due to mold and mildew from 25+ years of sitting in a near swamp. I'm using rockwool insulation and fabricating new heat shields from leftover 24ga stainless sheet.
The Dark Side of Will
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Re: Firewall Insulation

Post by The Dark Side of Will »

I have none on the Northstar car. Lack of it doesn't help the A/C any. I'm leaning toward getting something shiny to install... Switching to a Kirkey seat will probably get me to hurry up in that regard.

Here are some threads/links on the topic:

https://www.fierofocus.com/fierosails/Insulation.html

https://www.fiero.com/forum/Forum3/HTML/000077.html#p38

https://westcoastfiero.com/products/eng ... insulation

Edit: Try searching for "Fiero firewall insulation pattern"
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Shaun41178(2)
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Re: Firewall Insulation

Post by Shaun41178(2) »

I have none. Its not really needed for heat If you want to reduce noise that's a different subject
The Dark Side of Will
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Re: Firewall Insulation

Post by The Dark Side of Will »

The firewall gets pretty hot, especially after a long drive. There's insulation on the inside, but more insulation on the engine side would help more.
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CaptainHindsight
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Re: Firewall Insulation

Post by CaptainHindsight »

I have plenty of 24ga SS sheet that I'll cut to cover the rockwool. Trying insulate the heat as well as sound. The factory fiberglass has held up pretty well. It just has too many microbes, spores and fungi living in it. After finally removing all the trunk carper and lining as well you can get right up to the car without the strong scent of mold and mildew.

https://www.owenscorning.com/en-us/insu ... hermafiber

Will likely do this to the interior under the carpeting and console.

Image
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Emc209i
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Re: Firewall Insulation

Post by Emc209i »

Forum member Trinten paid me to install the shiny insulation on the engine side when I did his F23 swap. It works but it isn't pretty. What you and I are both after is the black fiberglass mat, which I don't know where to get from yet.

Heat shields, large and small, resonate and vibrate like you have no idea. I learned this in short order when I built some for my 3.4 DOHC swap back in antiquity. The stock heat shields have ribs molded into them to reduce resonance. If you build something out of flat stock its going to rattle like your mothers bed frame when you were conceived.
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CaptainHindsight
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Re: Firewall Insulation

Post by CaptainHindsight »

If you want black fiberglass insulation:
https://www.owenscorning.com/en-us/insu ... ic-blanket
https://www.buyinsulationproductstore.c ... thickness/

Yes I'm starting with flat SS sheet. The rockwool will be placed over a polymer insulator that is water proof to keep moisture off the painted steel firewall to prevent rust. There will not be any channels placed under the rockwool to prevent drainage obviously. The SS heat shield will be placed directly onto the rockwool that will act as a dampener for vibrations.

Old exhaust shields tend to rattle all the time and you have to solve for least vibration. If the firewall heat shield rattles you just have to investigate and quiet it down by adding ribs, lips, extra supports, etc. etc. Same as dealing with any other engineering issues.
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draven
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Re: Firewall Insulation

Post by draven »

My "plan" is to go with a layer of the boating engine bay insulation with an aluminum sheet patterned from a template from fieroGuru. Then polish, brush, lizardskin, or gold foil the aluminum based on the heat my setup produces.

Probably lizardskin the other three sides of the bay. Waiting on a nomad's C3 project where he's using lizard skin to decide... otherwise cover the three remaining sides with black fiberglass...
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