When you’re trying to make a lightweight 1977 Chevy Nova with a high-revving small-block 327 more livable, comfort usually takes a backseat. Project Mighty Mouse was built to scream, not coddle. But the heat, drone, and road noise that come with that kind of performance can get old fast, especially if you’re trying to actually drive the thing. While we are waiting on the final engine parts, now is the perfect time to address future concerns about the heat and road noises. We took the opportunity to get ahead of the problem using the Design Engineering Inc. ATAC barrier system.

Meet The DEI ATAC System

To deal with the heat and sound, we turned to the team at Design Engineering Inc. (DEI). They’ve built a reputation for creating effective thermal and acoustic solutions for everything from full race cars to daily drivers. Their New Advanced Thermal Acoustic Coating (ATAC) and matching Red Oxide Primer caught our attention because of its ability to handle both heat and noise in one step. Both products are water-based, easy to clean up, environmentally friendly, and proudly made in the USA.

Interior Removal And Prep Work

The first step was stripping out the interior. The bench seat came out easily with four bolts, one in each corner. The seat belts were removed using a T50 Torx bit. This was also a great time to vacuum out debris and get the floor ready for cleaning. We wiped down all exposed metal using brake cleaner to make sure the surface was clean and free of any oil or residue.

With the interior fully stripped, it was also a great opportunity to make any necessary upgrades. If you’ve been meaning to rewire anything or inspect your floorpans, now is the time. With full access to the cabin, jobs that would normally be frustrating become much more manageable.

Using a ratcheting wrench to remove your bench seat is the key. A normal ratchet setup is too bulky, and a normal wrench is slow. This was a huge headache saver.

Before diving into the coatings, safety was a priority. We wore a 3M respirator throughout the prep and spray process to avoid breathing in any fumes or fine particles. It’s something I didn’t take seriously enough back in my teenage years, but as I’ve gotten older and a little wiser, I’ve learned that protecting your lungs is worth the effort, even when using water-based products like these.

The brake cleaner helped prep the surface for the primer. The respirator definitely saved some brain cells, seeing how the fumes can build up while spraying stuff in the car cabin that’s closed off.

The Sprayer And Application Options

We opted for DEI’s dedicated ATAC Spray Gun, which is fitted with a 2.0mm tip designed for the thicker consistency of both coatings. It gave us excellent control and helped produce a uniform texture without clogging. While we used the spray gun, both the Red Oxide Primer and ATAC can be brushed or rolled on, depending on your tools and workspace.

Spraying The Primer

After masking off surrounding surfaces and setting up fans for ventilation, we got to work applying the Red Oxide Primer. This base coat helps prevent corrosion and improves adhesion for the ATAC layer that follows. Even though it’s marketed as a brush-on product, spraying gave us smoother results. We applied the primer at 40 psi and found it laid down evenly without any clogs or splatter. After the first layer, we waited 12 hours before applying the second. Then, we gave it a full 24 hours to cure before moving forward.

Spraying The ATAC

With the primer fully cured, we moved on to the main event, spraying DEI’s ATAC coating. This material combines thermal and acoustic insulation into a single application. It’s designed to block radiant heat and reduce vibration-based noise, making it ideal for performance builds like this one. We used DEI’s spray gun again, this time at 60 psi. That fell right in line with DEI’s recommended range of 60 to 80 psi. We sprayed on two coats, giving it 12 hours between each. Thanks to the humid Missouri weather, we let it cure for 48 hours before putting anything back inside the car.

ATAC is different in that it does both heat and sound control in one product. We have found others need to use two different coatings to get both heat and sound control. That is the main benefit of this product. You can also use damping material right over top of this as well if the build needs to have extra damping and vibration control properties – Steve Garrett,  Sr. Graphic Designer

Product Testing And Comparisons

One of the most compelling reasons we chose ATAC over traditional options is its versatility. Most builders rely on a combination of heavy, asphalt-based sound deadeners and separate thermal barriers like foil-backed mats. That can work, but it adds a lot of weight and complexity. ATAC simplifies the process by combining both functions into a single product. It bonds directly to metal, reaches tight corners, and adds minimal bulk. It also doesn’t require an adhesive, which means no mess, no peeling back over time, and no fighting gravity during installation.

ATAC offers a clear weight advantage over damping material, especially when fully applied. Boom Mat is heavier, and full coverage adds significant weight. Damping material controls noise and vibration more effectively due to its mass. At 2 mm thick, ATAC performs similarly if applied to the same thickness. – Steve Garrett, Sr. Graphic Designer

DEI also confirmed that ATAC can be layered underneath traditional damping mats if needed. While the coating alone provides excellent thermal and acoustic control, it gives builders the flexibility to adjust their interior to meet specific goals. With ATAC, there is no limit on the number of layers you can spray. The number of layers you spray affects how well the interior of your car is shielded from heat and noise. DEI recommends a minimum thickness of 12 to 16 mil. Just know that the more you spray, the more weight you’re adding. This means that there is a certain point at which you should either lay the Boom Mat on top instead of spraying more or use only something like the Boom Mat to achieve your goal.

Builders should also know that ATAC is compliant with both ASTM E84 and MVSS 302 standards. That means it passes flammability and smoke development tests used across the automotive and construction industries. Whether you’re building a weekend cruiser or planning on track time, that kind of safety certification adds peace of mind.

Real-World Performance Expectations

While the car isn’t back on the road just yet, we’re confident the ATAC coating will make a big difference. Cars like this Nova, running long-tube headers and no under-hood insulation, are notorious for cooking the footwells and filling the cabin with unwanted exhaust drone. ATAC’s rated 350°F continuous and 400°F intermittent temperature resistance means it’s well-suited for exactly that kind of environment.

DEI also pointed out one of the biggest benefits of ATAC: it handles both thermal and sound management in one go. That’s not just convenient; it saves weight and space compared to using multiple layers of mats, foils, and foams. In builds like ours, where weight savings and clean aesthetics matter, that’s a huge plus.

We’re particularly looking forward to the difference ATAC makes during long summer drives. With no functional air conditioning and that aluminum firewall delete panel sitting right behind the exhaust collectors, the interior could easily turn into a sauna. By spraying the firewall, floorboards, and trans tunnel, we’ve done everything possible to keep that heat out of the cabin.

Reassembly And Final Thoughts

After curing, we reinstalled the original carpet over the freshly coated floor. The ATAC gave it a clean, even base to sit on and added a level of heat and noise protection that will make a noticeable difference once the car is back on the street.

A plastic paint scraper made tucking the carpets under the trim light work.

Be sure to torque your seats and seat belts correctly upon reinstallation. The bench seat bolts down with the same four half-inch bolts, and the belts go back in with a T50. Since this is an older car with no airbags, these are your only real safety restraints, so take the extra time to get them right.

One major benefit we’re looking forward to is how ATAC helps insulate the firewall. Since we’ve deleted the factory AC and heater box, we have an aluminum panel in its place. That panel sits right behind the header collectors, which generate a ton of heat. Spraying ATAC on the inside of the firewall will go a long way toward keeping that heat from radiating into the cabin.

Impressively, neither the primer nor ATAC ran downwards after being sprayed on the firewall.

Overall, the DEI system was straightforward to install, and we appreciated the flexibility to spray or brush both products depending on the need. With the interior cleaned up, the floor protected, and the heat barrier in place, Project Mighty Mouse is one step closer to hitting the road in comfort and style.