Rear Trunk Heat, Trying to keep trunk cooler Options

[chads74]

I attemped trying to find something using the search and also google, but really only saw the rear insulator pad and dynomat.

What other ways have you kept the rear trunk from getting too hot? Lately I have been laying a moving blanket in the back when I want to take the car to the grocery store, so I can keep the plastic bags from melting to the metal. I would like something I can leave in the trunk and not worry about it.

[Michael RD]

Is your muffler heat shield in place ? (Under the trunk , over the exhaust.)

[bulitt]

Original carpet?

[chads74]

No heat shield or carpet in the trunk, and I am running a v8, guess I should have mentioned that. So I am not sure there is any hopes in lowering the heat back there.

I was thinking of adding some type of heat shield like the original exhaust heat shield. What is your experiences with it cutting down on heat?

[Michael RD]

I didnt realize a V/8. Headers? - Coating the exhaust? Wrapping the exhaust? Smaller rear valence? Diy heatshield? (IMG:style_emoticons/default/shades.gif)

[JmuRiz]

Installing the muffler heat shield and the stock dense rear trunk pad under the carpet should help a lot. I've never had issues with both in place on my car.

Using some other stick-on heat shield coating should work too.

[ThePaintedMan]

I agree with wrapping the exhaust Chad. You can usually find that fiberglass header wrap on Ebay fairly cheap, or from other racing suppliers like Pegasus or RacerPartsWholesale.

[SLITS]

While exhaust wrap keeps things cooler, it will cause the metal to crystallize due to the exhaust temp**. I don't know how long it takes for the metal to fall apart as we only wrapped the race cars.

** or so I was told

[Elliot Cannon]

Spray the underside of the trunk with VHT high temp paint. It makes a good insulator.

[chads74]

I have the headers/exhaust wrapped up the the mufflers, but still gets quite hot. No rear valence at all. I was thinking of a home made heat shield, steal or aluminum? Steal would be easy cause I could weld it to the bottom side of the trunk, but doesn't aluminum dissipate heat better? Would one of the stock heat insulators be the best option or is there something similar that is easier to get ahold of?

[Michael RD]

IMHO. - I would think a steel one. Dont just weld it flat to the trunk (underside) but put it on welded tabs or studs (removeable) to hold it off the surface, allowing airflow between the top of the shield plate and the trunk plate. What gauge mtl. you use depends on how many drops you want to retain it with.

[Andyrew]

Take a tip from the modern turbo guys. Grab some aluminum tape or gold tape and apply it to the underside of your trunk. It acts as a strong heat deterrent. Look up what the turbo guys use but there are a lot of products that work quite well. Combine that with some insulation in the trunk and you should be much cooler than you were
Id search for "heat shield diy "

[ThePaintedMan]

Forgot about the thermal gold foil. That is good stuff too. And not all that expensive considering.

https://www.pegasusautoracing.com/productde...asp?RecID=11221

[porbmw]

Forgot about the thermal gold foil. That is good stuff too. And not all that expensive considering.

https://www.pegasusautoracing.com/productde...asp?RecID=11221

It's been years now since I did it...but on my 930 I purchased a section of matting (it had a reflective surface...and the material in the middle had strands of fiber) and affixed it to a portion of the sheetmetal at the rear of the car that was getting REALLY hot....it did the job, and stood up well.

As recommended, see what the current recommended products are, as used by the turbo people....

[Dave_Darling]

The function of the heat shield is to prevent heat from going through it, not to dissipate heat. The only reason to use aluminum would be if you thought the weight mattered. (It probably doesn't, even in the lowest-powered and lightest of 914s--it certainly doesn't in a street-driven V8 conversion.)

Just use steel. And yes, mount it on stand-offs so there is air between it and the trunk floor.

Between that, and heat-reflecting foil, and a thick blanket on the trunk floor, you shouldn't be melting bags in the trunk.

--DD

[Harpo]

What about the front trunk?

David

[andys]

A heat shield with an air gap can be very effective at shielding heat, so your thinking is sound, IMO. As Michael mentions in his post, use some stand-offs and screw it in place. I'd opt for aluminum sheet to keep it light. Also, might have a sheet metal shop run a couple of beads to keep it from drumming.

Don't know what mufflers you're running, but I run FlowMaster's on my V8 for which they make heat shields specific to the 50 series mufflers. I also added heat shields to the tops of the exhaust pipes. Seems to be very effective.

Andys

[chads74]

Forgot about the thermal gold foil. That is good stuff too. And not all that expensive considering.

https://www.pegasusautoracing.com/productde...asp?RecID=11221

Not too expensive huh. George, you must make a lot more then I do.

So here is what I am thinking... High temp paint the bottom of the trunk, then make up a heat shield with a couple of the tabs welded on to make an air gap. Lets see if I can possably get that done this weekend and I'll be back to give results.

Thanks for all the input and good ideas that god my brain going.

[CptTripps]

Not too expensive huh. George, you must make a lot more then I do.

$32 for 12"X27"isn't expensive...what were you thinking of spending? You'd only need about 3' to do the whole area you're talking about. You may have more than $100 into paint and stuff by the time you're all done.

Wrapping the headers with heat-wrap like this is a good way to go, but I've been told that you need to be careful that oil doesn't get on it, as it'll permeate and then if it ever catches fire, you're kinda screwed.

Exhaust Heat Header Wrap 2 ROLLS

[chads74]

Not too expensive huh. George, you must make a lot more then I do.

$32 for 12"X27"isn't expensive...what were you thinking of spending? You'd only need about 3' to do the whole area you're talking about. You may have more than $100 into paint and stuff by the time you're all done.

Wrapping the headers with heat-wrap like this is a good way to go, but I've been told that you need to be careful that oil doesn't get on it, as it'll permeate and then if it ever catches fire, you're kinda screwed.

Exhaust Heat Header Wrap 2 ROLLS

Guess I was thinking I would need more then 3' of the gold foil.

edit: That heat wrap on ebay looks like a good price. I might have to pick some of that up to wrap the mufflers.