Internal combustion engine applications generate a lot of heat and sound. That's just the nature of the beast. And though many parts are designed with that in mind, it's not something you should necessarily leave unaddressed.
To manage thermal conditions and keep a cap on unwanted noise, many people turn to heat shields and protective wraps, as well as sound absorbing/dampening materials. While some builders dismiss these add-ons as an unnecessary expense, it’s important to point out that more than just comfort and style are on the line -- we’re talking about performance and reliability as well. Excessive heat in particular can really do a number on your vehicle, from melting wires to leaving you with a vapor-locked engine that eventually breaks down.
Ultimately, determining whether the investment is worth it for you comes down to understanding a little bit more about what insulation brings to table, and how it might benefit your application.
Keep reading to learn what exactly these products are, and some of the common ways they’re put to use.
Breaking Down Heat & Sound
OEMs send their cars out with insulation to deal with heat and sound for a reason. Some builders might strip some of it away in the name of weight savings, but that doesn't mean there's no point to it.
Hot and loud cars simply don't sell. Manufacturers have to do what they can to keep these factors under control to ensure their cars are comfortable enough to drive on a daily basis.
Insulating is how that's done.
Every panel of the cabin is backed with insulation of some kind to dampen sound levels and keep heat isolated. In combination with additional components to achieve similar goals and those that reduce vibrations throughout the various operating systems, you end up with a pretty cushy environment anyone can enjoy.
That's not to say insulation products are necessary solely for those applications and don't have a place in the performance world.
Heat causes a lot of problems in terms of performance and longevity. If you don't keep it under control, it can easily rob you of horsepower and quickly lead to the destruction of parts. So even if racecar drivers are willing to take hits in terms of creature comforts to save on weight, you'll have a hard time finding a serious machine without insulation protecting delicate parts from heat sources.
So, to start with the basic question of whether or not it's worth insulating for heat and sound, the answer is yes. About the only time you wouldn’t is when you’re modifying very little with the factory insulation in place.
Insulation for Safety and Comfort
If you're building a daily driver or cruiser, the engine is probably pretty close to stock, and the primary concern is insulating the cabin for comfort. That's where manufacturers like Dynamat and Thermo-Tec come into play. They have a long list of sound-deadening and insulating mats to improve comfort.
These mats are what you see stuck to the metal behind the carpets and door panels to keep sound and heat out of the cabin. If you want to eliminate as much sound and heat as possible, you could add these mats to every panel possible, which is extremely effective.
Alternately, you can pick and choose where you apply them. Many builders use less mats to save weight. Though cutting down does increase noise, effective placement can still reduce the harshest sounds to balance comfort and performance.
In the case of the average performance build, there are a few key areas you need to keep in mind. More specifically, you want to be mindful of anything coming close to the exhaust.
Starting with wiring, there are some simple solutions to keeping shorts at bay. Basic wire looms are enough to prevent abrasions and minor heat sources from ruining your day, but they won't cut it if a wire bumps up a hot header. In this case, DEI is the brand to look to. They offer sleeves designed to be used specifically with spark plug wires, as well as for more general purposes that protect anything within from extreme heat. At the very least, this simple addition will save you from a performance-robbing misfire. At the most, it can prevent an electrical fire.
The same can be said for fuel lines that run close to heat sources. It's not uncommon for fuel to boil if heat isn't controlled in a high-performance application. Obviously, that's a recipe for disaster, and insulation is a way to prevent that from occurring.
Preserving Performance
Safety is a primary concern, but it's not the only reason insulation has its place on your vehicle. Any motor head will tell you that heat, while a byproduct of power production, kills performance.
Cooler air is denser and able to contain more oxygen. That's part of the reason why cold air intakes, intercoolers, and hood scoops are such a big deal in the performance world. They don't have to fight the battle alone though, as insulation can work wonders in this department as well.
Take header wraps, for example. They help keep the heat in the exhaust system, reducing temps in the engine bay. This simple change can help improve the quality of air available to the engine for better combustion and keep the engine operating temps at optimal levels for enhanced gains. The heat also helps "lubricate" airflow through the exhaust system, so keeping it contained there offers even more gains.
Insulation can also be applied to intake hoses to help keep engine bay temperatures from influencing air flowing within. A simple layer of heat-reflective tape can be a worthwhile modification if you're after the coolest, densest air charge possible.
User-Discretion Advised
These are all just examples, and they may not apply to every situation. DEI, Thermo-Tec, Dynamat, and many others offer insulative products to solve a number of problems. However, to get the most out of it, you really need to understand the problem you want to solve and how insulation will help.
On its own, insulation is a simple piece of material that is good at dampening vibrations and deflecting heat. It's up to you to decide what's right for your situation.