Let’s face the facts, cars are noisy and get really hot, especially kit cars. Unlike production vehicles, kit cars aren’t required to have pounds upon pounds of sound-deadening material or heat shields of any sort; the kit car manufacturer leaves that up to the customer.
Our Factory Five Cobra Jet Challenge project came to us as a frame with a fiberglass body mounted on it, with boxes and boxes of parts supplied to get it rolling. The engine, transmission, brakes, rearend, etc., were left up to us, which is why building a kit car is awesome; we can build it as we please. The 625 horsepower Coyote engine and Tremec T-56 Magnum transmission we chose for the build will make a lot of heat, and ultimately be really noisy, as riveted aluminum panels are the only components that separate the engine and transmission from the footwell and the rest of the cockpit. Out on the racetrack, heat can fatigue drivers and cause them to make mistakes. We need to beat the heat and keep the driver cool with this build.
For our build, Heatshield Products supplied its sound-deadening materials to cut ambient noise and vibration, as well as thermal-shielding products to keep the heat off of various lines that are in close proximity to the engine.
Keeping It Cool
Heatshield Products produces a plethora of sound-deadening and heat-insulating products, but our car didn’t come with any of that, which is why we wanted to keep it as lightweight as possible and still meet our needs. To dig up more information about the products and other uses, we sat down with Steve Heye of Heatshield Products for a little lesson on what we’re using.
On the racetrack, things can get heated up quickly for the driver and the car. With the engine running between 3,500 rpm and redline the majority of the race or session, the firewall and floorpan will get amazingly hot. With Heatshield Products’ Stealth Shield, we’re not too worried about our feet getting cooked in the footwell because it is rated for a continuous 1,800 degrees, and 2,000 degrees intermittently.
“The best way to stop heat is at the source,” Heye stated. “A lot of times that can’t be accomplished, but the next best thing to do is to stop it at the floorpan, firewall, or transmission tunnel before it gets to the metal. Once heat is into metal, it’s hard to soak it up.”
We were curious about what materials were used to create the Stealth Shield, and Heye had a good explanation for us.
“It’s actually technology we took from our welding blankets. You can hit a torch on one side, put your hand on the other, and it’s not going to burn. The material is called PAN-carbon, and it is extremely efficient at displacing thermal energy,” Heye explained.
For those that aren’t too in-tune with carbon fiber, PAN-carbon is carbon fiber that is made from polyacrylonitrile. About 90-percent of the fibers are polyacrylonitrile, while the other 10 percent of the fibers are made from rayon or petroleum pitch.
At just 1/8-inch thick, the Stealth Shield also applies very easily, and can be used over existing sound dampener products. If you have your car stripped of its carpet, all you have to do is lay it down and reapply the carpet. It can also be used in the headliner of a vehicle, but to keep the headliner from sagging, it needs upholstery adhesive. There are so many uses for the Stealth Shield, but in our Factory Five Cobra Jet Challenge project, it will be put to the ultimate test on the racetrack.
For the aluminum panels in the footwell, Heatshield Products supplied us with its sprayable DB Skin, which is a water-based, air-curing, vibration-dampening compound that bonds to sheetmetal, wood, plastic, and fiberglass surfaces. A proprietary blend of silica-mica and ceramic suspended in advanced chemical binder, it creates friction that greatly reduces structural resonance and vibration. It can also dampen vibration in a variety of panels over a frequency range of 10-40 kHz.
DB Skin adheres into every little crevice it’s applied on. For example, with a car that that’s stripped down and prepped for track duty, the DB Skin can be applied to all of the bare areas of the vehicle’s inner structure. It can also be applied to the outer door skins, and above the headliner.
“If you gut an interior, it’s really ideal to use the DB skin because it fills into all the nooks and crannies, which helps get rid of a lot of vibration noise. Panels can become loose, other parts flex over time, and the DB skin knocks the sound out without adding a lot of weight, turning the car into a big pig,” Heye quipped.
DB Skin can be applied in a variety of ways, such as spraying, brushing, or even rolling it. If you do choose to spray it on, your best bet will be to obtain a shutz-style spray gun, which will save you a significant amount of time applying it. For our application, we chose to roll it, but we’ll get into that during the install overview.
The final piece to the puzzle is Heatshield’s Hot Rod Sleeving. This thermal sleeve is capable of withstanding 1,200-degrees continuously, and 2,000-degrees intermittently, and is great for smaller lines and wires that are in really hot, tight places, such as the engine bay. With our Tilton three-chamber reservoir mounted to the firewall, the NiCop lines lead to the front brakes are going to be exposed to a lot of heat, especially the line that runs near the steering shaft next to the header.
“The cool thing about the Hot Rod Sleeving is that it is lightweight, does great in close quarters, and has a great OEM look to it,” Heye explained. “It’s got that old school look to it, but with modern technology; it’s a stealth way of keeping things cool.”
The Hot Rod Sleeving is a great addition to our engine bay, especially since everything is shoehorned into such a tight space. There will be a lot of heat radiating from the area, but we’re not too worried as many of the components will be protected by the this ingenious product.
Installing And Applying
The great part about the insulation and sound deadeners that Heatshield Products supplied us with is that they’re not hard to apply by any means. Since our brake lines run to their respective corners, we decided to install the Hot Rod Sleeving on the fuel line that runs parallel with the transmission as well; that line is going to get really hot. One line that really needed the Hot Rod Sleeving was the driver’s side front brake line after the bulkhead. The line is so close to the header, it would definitely contribute to boiling the brake fluid.
When it came time to secure the Hot Rod Sleeving to the lines, it needed to be adjusted correctly, then simply heated on both ends to keep the sleeve in place. This is to ensure that no heat can get past the sleeve seals.
Applying the DB Skin wasn’t a hard task at all, and it can be done in an afternoon, depending on the size of the project. To apply the DB Skin, you can use a shutz-style spray gun as we mentioned earlier, a paint brush, or a paint roller. The aluminum surfaces we’re going to be applying the DB Skin to didn’t need to be prepped in any intricate way, just wiped clean of any contaminants with isopropyl alcohol, preferably 91 percent. After we cleaned the surfaces, it was time to start applying.
The aluminum pieces were already powder-coated on the sides that will face the engine bay, so we’ll be applying the DB Skin to the inside of the footwell panels. We decided to take the different route and roll on the DB Skin, and it worked great; just give it a little time to cure, and it’s good to go. We also applied DB Skin to all of the panels that will make up the cockpit, rolling it onto the bottom side of the panels that will face the pavement and rearend.
Once we installed the pieces of the footwell that were powder-coated and had DB Skin applied, we laid down the Stealth Shield mat. In order for it to fit in all of the spaces, we had to cut it to the specs of the areas. The Stealth Shield doesn’t require any kind of adhesive for installation, but we used a high-temp interior spray adhesive to get it to stick to the sides of the footwell.
Overall, we tackled the whole footwell, the underside of the car, brake and fuel lines, and applied the Stealth Shield. It did help that our car was nearly bare to start with, too. We’re very happy with the quality of the products that Heatshield Products supplied us with, and we can’t wait to hit the track to really put them to the test.