18 It’s worth noting that wrapping the headers doesn’t get rid of the heat of engine combustion, it just holds it in the header pipes. As you can see, they are still glowing inside the wrap. We didn’t see any horsepower gain on the dyno, but that was because the engine is being fed temperature-controlled air into the carburetor. In a race car the wrap will significantly reduce under-hood temps, and if you don’t have a hood scoop it means the air going into the engine will be cooler. Using a wrap or some type of coating to keep heat inside the headers will keep components, oil and even the air/fuel charge cooler, which should make for a healthier, stronger racing engine.