Hot Air Robs Power: How to beat the heat
|In order to defeat heat in your engine bay, you have to know the causes of it. High underhood temperatures decrease the density of the air entering your engine, and hurts your power output. On top of that, heat increases your chances of "detonating". Detonation is when the air and fuel doesn't ignite evenly across the cylinder, causing the air/fuel mixture to explode unevenly. Detonation can cause large amounts of damage to an engine very quickly (most commonly the pistons, rings, and head). So why do we wan't be to beat the heat? Simply put - colder air is more dense than warm air, and thus creates more horsepower, and safer engine conditions.|
|What are the causes of heat|
Many things create heat on a vehicle. The following sentences will cover the primary contributing factors to heat on your vehicle.
1) Perhaps the biggest contributor of heat is the ambient air your car is breathing. On a hot day, the air your car is taking in is already poor. There's not a lot we can do about this - but its good to be aware of.
2) Another major player in the heat game is your engine itself. Hot parts under your hood create a closet of heat in your engine bay. This heat spreads to all other components under the hood.
3) Another contributing factor is simple maintenance and upkeep. If your radiator isn't full to the top with coolant, then you are already starting to let heat take over. Proper maintenance is key to keeping your ride running cool.
4) Ineffeciency. This comes into play more with forced induction fed engines. Compressed air is HOT already, but using the wrong size of turbo can make things much, much worse.
5) Outside conditions such as long, steep hills, and stop and go traffic can play hell with your vehicles temperatures as well.
Now that we know what causes heat, lets do what we can to prevent it, and lower air intake temperatures.
Heat from ambient air
Heat from ambient air can be reduced by having your air filter in an open area, where it gets a lot of fresh air from outside the engine bay. Cowl induction hoods, cold air intakes, and ram air are all effective ways of drawing cooler ambient air into your engine.
Hot engine parts = hot engine bay
There is only so much you can do about hot engine parts in your engine bay. They're going to get hot. . . we can't stop this, however we can soften the blow from it. One way to "kill" the heat is to not allow it to escape from the places where it resided to begin with. This can be done many different ways, here are a few:
Jet Hot Coating
Thermal Heat Wrap
Getting your exhaust manifold wrapped, or coated will drastically decrease your engine bay temperatures. This also puts more stress on your manifold, but this is when buying quality parts pays off.
Aside from wrapping your "hot parts" to keep the heat in, creating air passages into your engine bay will also help to keep the heat down. If cold air (at driving speeds) is able to easily enter your engine bay and push out hot air - engine temps will decrease.
Maintenance and Upkeep
This should be a no brainer, but it never ceases to amaze me how often it is overlooked. If you don't check your coolant regularly, you could be giving up valuable cooling provided by the top rows of your radiator (if there isn't any coolant on the top rows). It is also necessary to make sure your fan(s) are in proper working order. . . a malfunctioning fan could mean sky high engine temps in a very short period of time. Even simple things like, making sure your radiator cap has a good seal, making sure your oil is changed in regular intervals, and making sure there is no air in your coolant system can save you tons of heat related heartache. Good upkeep is key to enjoying your ride for years to come.
Compressed Air and Inefficiency
Whenever air is compressed, heat is generated as a result. The air receives a good deal of this heat. While some forced induction motors simply breathe hot air all the time - it isn't the only option. Some options to look into are:
Air to air intercooler
Air to water intercooler
All of the above devices are used to cool the compressed air down as much as possible before it hits the cylinder.
Now we know that compressed air is hot, but what about inefficiency and heat?
On a turbocharged vehicle, the size of turbo being ran plays a BIG role in the temperature of the compressed air it creates. A turbo that has to spin far faster than it was intented to spin will quickly become extremely hot, and inefficient. This creates very high intake temperatures, and will decrease the horsepower output of a vehicle.
For example. If Joe's stock turbo on his Eclipse is only meant to push 15 PSI of boost, and he's pushing it to 20 PSI, chances are he's blowing HOT air, and is at risk for detonation to occur in his engine. If you want to make X number of horsepower, make sure you get the proper size power adder for your goals, or you may end up in this position.
You can't change your surroundings...per say. You can however be aware of your surroundings to avoid nasty situations. Steep hills, and stop and go traffic will cause your car to run much hotter than normal. Just know your surroundings, and don't try to push your car too hard under these conditions.
Heat's a bitch, but beating the heat can be done effectively - and the rewards are plenty.
Aside from the tips mentioned above, here are some other performance parts that may aid you in "beating the heat".
Air Directional Inserts