Corvettes give us many reasons to love them, but there are also some issues that provide plenty of room for improvement. Insulation is one of those areas, as original Corvettes eventually start transmitting road noise inside the car, and we all know the feeling of heat resonating into the cockpit. When restoring or customizing a vintage Corvette, it’s always a good idea to install a barrier between the fiberglass and the upholstery in an effort to insulate the cockpit from noise and unwanted temperature changes. For our C3 project car being built up at Hot Rods by Dean in Phoenix, we used a series of Dynamat Xtreme Custom Cut kits, which are designed for either the coupe or the convertible. The pre-cut kit means you don’t need to take a razor knife to make holes for bolts to pass through, and it also means trouble free carpet and upholstery installation.
For our project, we ordered the floor kit, trunk floor kit and door kit. We also grabbed a couple rolls of DynaTape to cover the seams and a rubber roller to press the material into the crevices of the floor, doors and storage areas. Installing the Dynamat material was straightforward and simple, but getting your car prepared can take some time. Luckily, we were coming from the ground up with our C3 build, but if you’re planning to insulate your car with Dynamat, it would be a good idea to plan some other upgrades while you have every stitch of the interior out of the way. New carpet is a no-brainer, and you can easily rack up a hefty bill at your favorite Corvette parts supplier if your Corvette’s interior is stripped down to the bare bones. (Later, we will show you how to install our Summit carpet package for the C3 Corvette along with the upholstered seats and our door panels from Corvette America.)
The beauty of Dynamat is that it made an instant difference in our Corvette. It gives the car a more solid feel and definitely provides a more solid “thunk” when closing the doors. Whether or not your car will be outfitted with air conditioning, the heat barrier is a nice feature of the Dynamat material. Overall, the Dynamat installation took us a few hours, but we were starting with an empty shell. If you’re installing Dynamat on your driver, expect several hours of removal and installation (R&I) of interior parts to get the job done. Either way, this sound and heat barrier is a worth every hour and every penny you spend on it.
1. We’re using a Dynamat Xtreme Custom Cut kit, designed specifically for 1968-’82 Corvettes. Dynamat offers a floor kit, trunk floor kit, door kit and roof kit, which provides the ultimate sound damping and heat protection on all surfaces.
2. The Dynamat Xtreme Custom Cut kits feature pre-cut pieces of the insulation material. We cut the paper backing to lay out the pieces to make sure the orientation is correct before adhering them in place.
3. The passenger footwell was our first area of concentration. Obviously, the interior is stripped down to the bare minimum, but we also vacuumed and cleaned the floor panels before laying down the Dynamat material.
4. Dynamic Controls (makers of Dynamat) also offer this rubber roller, which is a must-have item when installing Dynamat. You’ll find that the adhesive side of the Dynamat is extremely sticky, but it still needs to be pressed down firmly to properly adhere. This roller does the trick.
5. With the footwell area completed, we lay out the seat area. Notice the precise cuts, which make this a straightforward install. Once we’ve decided on the final location, and prepped the floor surface, it’s time to remove the paper backing and lay down the material.
6. We carefully lay the floor section of Dynamat material in place, and then press it down with the roller. Next is the transmission tunnel side strip.
7. The pre-cut pieces install in the flat areas, and typically stay out of the compound curves. Notice the gap between the floor sheet and the narrow strip that goes alongside the transmission tunnel.
8. To help fill in the gaps, we used DynaTape. This is a 2-mil aluminum finishing tape, which offers continuous coverage in the hard-to-reach areas. We simply remove the paper backing and install it to seal up the seams.
9. The rubber roller works nicely to remove air bubbles and ensure proper adhesion of the DynaTape.
10. Once again, we cut the paper backing, allowing us to test fit the Dynamat sheet, but this time it’s on the support panel behind the seats. When we’ve determined the proper location, we remove any debris from the surface and then carefully place the sheet.
11. Moving on to the doors, we are using the Dynamat Xtreme Custom Cut XGM C3 D door kit. The installation of Dynamat on doors helps with pesky rattles and clunky noises when closing the door.
12. The custom-cut kit makes for easy installation, but we’re sure to press the material into the nooks and crannies of the inner door surface to make for a long-lasting bond.
13. The Dynamat kit even comes with small pieces for use on the door inspection cover and areas around the window regulator. These pieces may seem small but they play a big part in making this Corvette feel better than new.
14. Using the Dynamat Xtreme Custom Cut Trunk Floor kit (part number XGM C3 T), we start with the storage area behind the seats. This area is a common source for trapping heat and resonating road noise and vibrations.
15. The area behind the seats of a Corvette is often hard to access, but it’s worth the effort to fully insulate the interior. The flat sections of the trunk floor kit are easy to install; simply peel, stick, and run over it with the rubber roller.
16. With the trunk floor kit installed, we’re ready to fill a few of the gaps with DynaTape and then it’s time for some fresh carpet inside our C3 coupe.
17. Although the car is still “empty,” the difference when closing the doors is substantial. Once the carpet is installed and the remainder of the interior is assembled, this car will be quieter and cooler than ever before.
Photography by Brian Brennan