under carpet heat insulation

[bluecoupe30!]

I often see a product like Dynamat applied to the inner floor before carpets. This product specifically speaks about noise reduction. With the suffocating heat soak that we experience inside a Coupe, I feel this is an excellent opportunity to introduce a product that can also minimize heat transfer into the cabin. What have you used and are you happy with your choice? Also, between this self adhesive barrier, did you also add some foam, or jute or whatever, underlayment, before finally finishing with your nice, new carpet? Thanks, Mike

 

[rsporsche]

sound insulation is different than heat insulation. probably best to stop heat soak by insulating the tranny tunnel (inside and out) to shield the temp from the exhaust. the first thing to consider is this heat shield where the exhaust goes under the firewall. this is a pic from Coupeking's website. this is a BMW part that is not expensive and is used in conjunction with the firewall insulation ... which is NLA from BMW. you can buy an aftermarket piece from Coupeking or CS Werk. what i like about the Coupeking piece is that it extends down to give better heat protection where the exhaust goes down.

the next thing to do is to insulate the rest of the tranny tunnel. we are going to try the piece from the e12 / e28 and see if we can make it fit. somebody else on this forum had made one with flexible insulation that looked pretty nice ... but don't remember hearing how it worked out.

after you do the underside, you can use spray-on thermal insulation on the tranny tunnel and use whatever sound insulation that you want on the rest of the interior (spray-on or dynamat). be advised that dynamat can be quite heavy.

 

[eriknetherlands]

sound insulation is different than heat insulation. ..... somebody else on this forum had made one with flexible insulation that looked pretty nice ... but don't remember hearing how it worked out.

We'll you may be referencing to my attempt at solving the heat soak. I made this heatshield out of an E60 part. As i haven't driven my car yet, i can't say how much difference it makes. I als have the part that RSPorsche mentions; I'm sure that will also make a tremendous difference; perhaps even the same amount as the large shield I've added additionally.

 

[bavbob]

Since I had the interior gutted, I put a butyl -based heat and sound barrier, .067inches in thickness throughout the interior, including the tunnel and firewall. On top of this, I used Dynamat, 1/2 inch foam on the floor pans, tunnel and up the firewall as far as possible. This all about matched the thickness of the original stuff (that black stuff and the rubber/foam matting). Then carpet and then cocoa mats. The dynamat is self stick but I exposed the self stick only along the edges in case I ever needed to remove it (taking the original insulation out by hand....well you get paranoid).

Those snorkels along the firewall have been mentioned and I made sure I got those (still avail at La Jolla but a few more bucks than the website states). WRT how it all functions, I feel nothing along the tunnel or firewall (on my CS is stock). Entire exhaust is also painted with VHT ceramic paint. No heat shields as of yet.

 

[HB Chris]

I don’t know why but I’ve never experienced the dreaded heat soak from the exhaust even in Paso Robles coming home from Monterey when it was 95 degrees, and that was before I fixed my A/C system. And I don’t have a heater bypass either, maybe I am just lucky.

 

[eriknetherlands]

I've had my radio die on me on longer trips in the summertime here in the Netherlands because the thing would just reach boiling point. After a 15 minute coffee break it would have cooled down enough to work again for 45 minutes. (Could that have been from the exhaust, or was there something wrong with radio?)

 

[Cornishman]

On a RHD the drivers side, right, is a lot hotter than the left side. This is due to the route of the exhaust. On my RHD car the non standard exhaust sits even further to the right.

Does anyone have concerns over any of external these heat shields collecting and holding water if accidentally driven in the wet?
Does Dynomat, or similar products, seal so well that water can.t get underneath it and keep the inside floor wet? With carpets they can be pulled out if wet.

 

[bluecoupe30!]

A lot of useful info here, and quite creative "prototypes". I am trying to determine what product of all of the foil and adhesive, thin types of heat or sound barriers to use. Dynamat ,HushMat , XMat etc, and others are out there. I will choose something like this, then perhaps something on top. In fine print, these products mention they work really well if you put some other adhesive foil product on top. Then I would place some type of underlayment then carpet.
This all started with heater service, so now interior is gutted. Will complete this inner floor prep and perhaps I can drive again. The under-the-car heat remediation, will be for another day. Thanks for all the input.

 

[Drew Gregg]

sound insulation is different than heat insulation. probably best to stop heat soak by insulating the tranny tunnel (inside and out) to shield the temp from the exhaust. the first thing to consider is this heat shield where the exhaust goes under the firewall. this is a pic from Coupeking's website. this is a BMW part that is not expensive and is used in conjunction with the firewall insulation ... which is NLA from BMW. you can buy an aftermarket piece from Coupeking or CS Werk. what i like about the Coupeking piece is that it extends down to give better heat protection where the exhaust goes down.

the next thing to do is to insulate the rest of the tranny tunnel. we are going to try the piece from the e12 / e28 and see if we can make it fit. somebody else on this forum had made one with flexible insulation that looked pretty nice ... but don't remember hearing how it worked out.

View attachment 126252

after you do the underside, you can use spray-on thermal insulation on the tranny tunnel and use whatever sound insulation that you want on the rest of the interior (spray-on or dynamat). be advised that dynamat can be quite heavy.

I have the Coupe King firewall insulation and the tunnel Header metal piece installed. They seem to keep the heat out from below. The metal plate needs to be secured with weld nuts. I have extras if anyone needs them.