4x4jeepmanthing

Hey all,

Im looking for your suggestions on heat shielding, mainly over the Trans tunnel area and exhaust.

Ide like a non spray product, dynamat or similar options.

I am taking other steps to reduce heat via upgrading the little stock Trans cooler to a bigger b&m,and probably adding an airbake pan above the muffler/cat.

My interior is carpeted still so I'll be pulling it to install something. Sound deadening is a bonus but not a priority so thank you for any suggestions!

DustyWagoneer

A week and a half ago I drove my XJ to Ouray,CO from SOCAL.
Driving through the hot Mojave desert, and Utah, Nevada, AZ, NM deserts was brutal!!

But a few things learned about how hot things get in the XJ from my 2000 mile trek.
First thing is that the trans tunnel gets boiling hot.
I can see why the Jeep engineers ran the AC duct under the console. I had some candy in a bag in the console and it was completely melted. Hand sanitizer was at boiling point too.

Secondly, The cabin in the Jeep was crazy hot as well.
I installed foil lined ThermoTec insulation in the jeep a couple years ago thinking it would help with heat management as well as sound deadening?
Well it did, but to be honest it was not enough to do the job right. Face it, AMC Jeep wanted to make the XJ affordable, and did not want to spend a lot of money on it. ChryCo just caried on with AMC's design until 97.

Thirdly: The fuel was at boiling point in the tank.
I had major vapor lock going across the Nevada desert at night when it was still 105* out. I found that topping off the tank when it got to 1/2 helped cool the fuel pump down, and keeping it from vapor locking on me.
But I know I need to look at doing some heat shielding back at the tank where the exhaust runs next to the tank.

So I have been doing a bunch of thinking on how to help fix these three areas of heat penetration into the cabin, and in the gas tank.

First off your on the right track with some kind of heat shield for the catalytic converter and muffler.
The transmission tunnel however your gonna need to address the problem from underneath the XJ. If you have a center console, you will not be able to add to much insulation there. The mounts for it are close to the sheetmetal, and if you add to much insulation your console will not screw down to the floor without breaking the already brittle plastic.
I am thinking of buying some of this stuff to mount underneath on the trans tunnel; https://www.pegasusautoracing.com/pr...p?Product=1828
I have new to me seats, so when I goto install them I will add another layer of thermotec on top of the other one. But just cut out where the center console goes, as to not lift it any higher.
In the pictures you can see I put the foil side down against the floor pans, and firewall.
The next layer I will put the foil side towards the carpet.





You can see the front console mount. The carpet was right to the top of that mount.

On the underside of the tranny tunnel I think I am going to use this stuff?


That is the heat shield from Pegasus racing.
I used that stuff on my old Porsche 914/6 race car on the firewall, and it kept me much cooler on race days.
I might also use that on my gas tank too??

5-speed might have some ideas to, as he road races, and heat mitigation is important to racers.
There is my .02 worth!

All I know is my trip was horrible till I got to cooler temperatures up in the CO mountains.

4x4jeepmanthing

First off thank you for all of your input, it has spawned more questions for what and how to achieve good results.

I feel your pain, I had recently replaced my exhaust and it cooked my carpet "tweakers stole my converter, its a big issue out here", so I have various reasons for finally tackling this issue. Every time I drive long trips into these CO mountains, this jeep is an oven and she works hard flinging bigger tires around.


I'm a little curious on the undercarriage application of the reflective adhesive shielding. Doesn't the undercarriage have undercoating on it and will such a layering stick to it?

Inside the vehicle, will putting your second layer with the aluminum side up change how this material works, as in locking heat into the cab?

Seeing your pictures has brought another thought to mind. How much surface area needs to be covered to be effective? None of these products are cheap, I certainly hope something out there works very well, and isnt too bad on expense. My initial thoughts were to coat the tunnel and passenger side floor pans with some heat shielding.

I'll be getting new carpet, the piling ( grey padding underneath the carpet) is something im curious about as well, though I belive it to be more for sound deadening, I assume it does help with heat as well.

Is it important to have an insulated layer vs say something comical like going bananas with many many rolls of heavy aluminum foil?

DustyWagoneer

I have to drop my tranny and tc, so when those are out I will take all the undercoating off. When those are out I will clean, sand and paint before I stick the heat mat on there.
I have to remove my exhaust to drop the tranny & TC. So when I do I will add heat shield above the muffler and cat.

My theory is for the foil side down on the sheet metal to reflect heat back, then up to keep cool in (or in the winter heat in).
If you buy the ACC carpet kit I would suggest going with the ""Mass Backing"".
I bought an ACC carpet kit for my FSJ Wagoneer with the Mass Backing, and it made a HUGE difference in sound deadening. It also provides a water proofing between the carpet and sheet metal.
It is a bit of a pain to get to lay flat, but carefully using a heat gun, or laying it in the sun for a while helps with that.

4x4jeepmanthing

ok gotcha, goo gone pro and a little heat works like a dream getting that stuff off btw. I'll keep the carpet molding tip in mind! It'll depend on how much extra it costs for the mass add on but I'll certainly look into this option.

I wonder if some aluminum sheeting on top of the thermo insulation layer would work instead of a double thick layer, unless that's what you want.
Ive ive found a few more manufacturers for heat shielding and might be narrowing down which I choose.


Has anyone ever made something like a fin or scoop that would help push air into the Trans tunnel to pull some more heat out, just spit balling a thought here, I have no idea if something like that is practical.