Story & Photos by Jim Youngs

While production cars benefit from countless hours of engineering to address insulation issues, that’s not the case with most replicas and project cars. You typically start with a fiberglass shell and a bare chassis, and then you’re on your own when it comes to controlling high temperatures.

Fortunately, the aftermarket offers a number of heat-control products, and that’s just what I needed for my Porsche RSK Spyder replica. I’d already been advised by the manufacturer, Thunder Ranch, that I would have to address some heat issues in the engine bay. That’s because the turbocharged engine, a 2,110 cc modified Volkswagen Type 1, sits in a rather tiny engine bay, with the turbo sitting just inches below the fiberglass cover. All the extra exhaust tubing in the bay radiates even more heat, exacerbating the problem.

So how does one reduce the underhood temps on an air-cooled engine? I had already installed a few heat-control items, such as a large-capacity oil pan and full-flow oiling (to improve distribution from the stock setup, which isn’t sufficient for higher horsepower levels). I also added an oil thermostat and a Derale 96-row oil cooler with an electric fan and thermostat. What more could I do?

I received some pointers here from the guys at Design Engineering Inc. (DEI), a firm specializing in “thermal tuning.” Based on their recommendations, I ordered their Titanium exhaust wrap, aluminized Heat Shroud, Fire Sleeve and Titanium Protect-a-Boots. These items have a wide range of applications and would be ideal for most any project car. The exhaust wrap alone is said to reduce underhood temperatures by 50% and can withstand 1,800 degrees F.

The Heat Shroud is a high-temp fiberglass fabric bonded to an aluminized material with hook-and-loop closure. Designed to reflect heat from wiring and hoses, it can fit on diameters ranging from a half-inch up to 1.25 inches and can be easily cut to length.

Fire Sleeve is an iron oxide, silicone-coated fiberglass sheathing that provides protection up to 2,000 degrees F for insulating hoses, wires, fuel lines and more. It comes in 3/8-, 5/8- and 1-inch inside diameter kits with finishing tape for seams and sleeve ends. Protect-a-Boots slip over spark plug wires to provide 1,200 degree F protection.

As projects go, installing these DEI products is rather simple and straightforward. DEI also offers other products aimed at any number of insulation and heat issues, such as Boom Mat heat and sound control kits, air tube covers, mats and other types of sleeves and shielding. So what have you got to lose? Just some excess heat!

Heat Control F20

Here’s our engine bay with all the heat-control products installed. We also plan to add a turbo blanket later on for quicker turbo spooling.