heat insulation for exterior of footbox

[BigShooter]

Hey Y'all,
I was a bit into my build before I started really thinking about sound and heat insulation. so for now, I have a layer of kilmat 80 on the interior panels of the interior (plus the FFR carpet), but I'm wondering if there is such a thing as heat insulation to go on the outside of the footboxes - particularly in the front which is so close to the headers. At this point in the build it's too late to do any spraying. Is there some type of layered material that looks good that could provide extra heat insulation in this area?

[Chopper]

I have DEI Floor and Tunnel Shield in my roadster. I think it looks decent, classic-ish, but take your time with the tape on the edges. Functionality wise, it works well. I have insulation under my carpet inside, this lowered the footbox wall temperatures another 10 degrees. Since this picture was taken I have added it to the top of the passenger footbox as well (minus the vin plate)

https://photos.smugmug.com/Cars/Cobra/n-PLTRn/i-HbNBFff/0/d24c566e/L/i-HbNBFff-L.jpg

If you don't mind a more modern look, I have seen Heatshield Products Lava Shield Matt and it looks pretty nice, it's a bit thinner than the DEI floor and tunnel shield.

Both are sold in a variety of sizes, just a couple of example links.

DEI Floor and tunnel Shield (Silver, also sold in black):
https://www.summitracing.com/parts/dei-050503

Lava Shield:
https://www.summitracing.com/parts/hsp-770002

[Ted G]

I used an additional sheets of aluminum with an air-gap. Theoretically, this might be the best option. You can also line the back of this with a lava shield if needed. I also have my foot boxes lined with Cool Mat. I think this is a good look where you can have the panels powder coated, polished or whatever look you are going for. Here is a couple of pictures:

172098 172099


Ted

[Alphamacaroon]

FWIW you may not need it. I worried about it a bunch, but after 2,500+ miles (many in 90+ degree days) I've never felt like my feet were uncomfortably hot. Keep in mind I do have 3 layers on the inside -> Noico sound mat -> Noico foam insulation -> Carpet.

[edwardb]

Same here. Two layers on the inside firewall (Second Skin Damplifier Pro, Dynamat 11101 Dynaliner), Lizard Skin thermal insulation and sound control everywhere else, plus carpet. Zero hint of heat into the cockpit with now ending my third season and 5,000+ miles. Also with plenty of hot summer days. Helped perhaps by the Coyote which is a relatively cool running engine plus the separate radiator cooling tunnel of the Coupe design. I like keeping the engine side clean and haven't found the need for anything there.

One other comment I always add to these discussions. Make sure you have absolutely no air from the engine compartment infiltrating the cockpit. If you do, will feel like the heater is always on and defeat your other heat mitigation steps.

[David Williamson]

I only used Dynamat on the inside of all the aluminum panels and I on a hot day it does get warm in the car but I really think it is from the sun not the under hood heat. Even the door sills do not get hot while the car is moving, after it has been stopped they get slightly warm, not hot. If the sun is out the AC is on especially it the car was parked outside.
David W

[Namrups]

Paul, Why did you use the Second Skin instead of the Dynamat for the sound deadening?

[Alphamacaroon]

Echoing Paul's comments on the heat intrusion from the engine bay... I have my cockpit pretty well sealed off, but funny enough the place I feel the most warm air coming in is from the door sill near the top front hinge. I can't tell if it's because I don't have that area sealed well enough off, or another theory I have is that the aerodynamics of the car cause heat to be sucked from the cowl vents and then sucked back in through the door and window area (I haven't put my windows on yet). It's not bad enough to scramble to fix it, but it's really the only place inside of the car I can feel any sort of heat coming from. Either way, the solve is to close up air flow gaps— radiated heat (like from the headers) doesn't seem to be a problem with this car.

[JohnK]

I chose to add some heat shielding on the exterior of the footboxes since I have catalytic converters in my headers. I have no idea whether they are necessary, or whether the Lizardskin heat + sound insulation I sprayed on the inside is sufficient. Nonetheless, here's what I did. I started with DEI Floor and Tunnel Shield II (https://www.designengineering.com/floor-tunnel-shield-ii-21-x-24/) material on the outer sides of the footboxes. This is a perforated aluminum material with an insulating layer bonded to it. I didn't want taped edges, so I came up with a way to roll the edges using my sheetmetal brake. Details here (https://thefactoryfiveforum.com/showthread.php?31167-Greek-Guys-Garage-Roadster-Build-9509-(Picking-up-the-chassis)&p=462793&viewfull=1#post462793). This material comes rolled up, so you need to straighten it out, but it never gets perfectly flat and you can still see some waves in it. The perforated aluminum is also a bit too soft to fold back on itself at the edges, and split in some places, leaving some razor-sharp edges. Not a big deal on the outer walls, as the body will hide them, but I wasn't 100% happy with the result. For the rest of the footbox panels that would be more visible, I switched to DEI stainless steel acoustical floor & tunnel shield (https://www.designengineering.com/stainless-steel-acoustical-floor-tunnel-shield-22-x-19/). This is a perforated stainless steel material, similar in appearance to the aluminum but is roughly 4x the price. It comes as a flat sheet and is quite a bit more rigid than the aluminum heat shield, so it lays very nice and flat. I used the same technique to fold the edges over to get a clean finished look, and this worked much better on the SS material. Details here (https://thefactoryfiveforum.com/showthread.php?31167-Greek-Guys-Garage-Roadster-Build-9509-(Picking-up-the-chassis)&p=464566&viewfull=1#post464566). I'm much happier with the finished product with the SS panels but using the aluminum in the non-visible areas is fine (and quite a bit less expensive.) Here are a few photos of the end result.

Stainless steel panels:

https://thefactoryfiveforum.com/attachment.php?attachmentid=151521&d=1627956429

Aluminum panels:

https://thefactoryfiveforum.com/attachment.php?attachmentid=150889&d=1626410239

[edwardb]

Paul, Why did you use the Second Skin instead of the Dynamat for the sound deadening?

No complaints with similar products from Dynamat. I've used Second Skin products before, find them to be high quality, and usually cheaper than Dynamat which tends to command premium pricing. Either, plus many others, are fine. Of course every brand claims theirs is the best. I haven't found a huge difference in what I've used.