Intercoolers

Front mount intercooler

An intercooler’s purpose is to cool air that has compressed in either a turbo or supercharger. When air is compressed its temperature rises drastically, upwards of 300 degrees Fahrenheit, and becomes less dense and less oxygen rich. An intercooler is an essence a heat exchanger, like your radiator.
There are 2 main types of intercoolers air to air and air to water. An air to air intercooler uses outside air to transfer heat, while a air to water uses water to transfer heat.

In an air to air intercooler cool air passes through the intercooler tubes heating both the tubes and eventually the cooling fins. At the same time air from the outside passes through the fins of the intercooler, the heat from the tubes and fins is transferred to the air passing by on the outside. When it comes to an air to air intercooler setup there are different locations setups, different inlet and outlet configurations and different sizes. Locations for a front mount intercooler include, side mount intercooler and top mount intercooler. The location of the intercooler is key when determining how effectively it will transfer heat. The optimal location is a spot where the intercooler will have forced outside air blowing directly on it without any interference. This is why front mount intercoolers are very effective at transferring heat. They sit directly at the front of the car so they constantly have air from the outside blowing through the intercooler fins. Usually the only negative argument for a front mount intercooler is pressure drop. Pressure drop occurs because the route the air has to take to make it from the turbo to the front mount intercooler to the engine is long and not direct. Many front mount intercoolers today have been designed to help air flow and decrease pressure drop almost to a non-issue.

Top mount intercooler

Another cool setup I like is the hood scoop scooping in air directly to a top mount intercooler, like a Subaru Wrx. A major disadvantage to this is that your intercooler sits close to your engine which heats up your intercooler drastically reducing its efficiency for heat transfer. An advantage to this setup is that the air flow route from the turbo to intercooler to engine is short creating a more responsive setup.

A water to air intercooler is much like an air to air intercooler but this setup uses water to transfer heat instead of air. Since water is much better at transferring heat than air, you can have a smaller cooler which makes installing and finding an optimal location/setup much easier. In this setup water is pumped through the air/water unit where it meets the compressed air. Here the heat from the air is exchanged to the water. After the water has been heated it follows a path to a heat exchanger, like an intercooler or radiator where the heat is then transferred out of the water. Some obvious disadvantages that are inherent to a water-to-air setup are weight and mechanical malfunctions.

How Car Cooling Systems Work

Diagram of a cooling system: how the plumbing is connected

Although gasoline engines have improved a lot, they are still not very efficient at turning chemical energy into mechanical power. Most of the energy in the gasoline (perhaps 70%) is converted into heat, and it is the job of the cooling system to take care of that heat. In fact, the cooling system on a car driving down the freeway dissipates enough heat to heat two average-sized houses! The primary job of the cooling system is to keep the engine from overheating by transferring this heat to the air, but the cooling system also has several other important jobs.

The engine in your car runs best at a fairly high temperature. When the engine is cold, components wear out faster, and the engine is less efficient and emits more pollution. So another important job of the cooling system is to allow the engine to heat up as quickly as possible, and then to keep the engine at a constant temperature.

The Basics

Inside your car's engine, fuel is constantly burning. A lot of the heat from this combustion goes right out the exhaust system, but some of it soaks into the engine, heating it up. The engine runs best when its coolant is about 200 degrees Fahrenheit (93 degrees Celsius). At this temperature:

• The combustion chamber is hot enough to completely vaporize the fuel, providing better combustion and reducing emissions.
• The oil used to lubricate the engine has a lower viscosity (it is thinner), so the engine parts move more freely and the engine wastes less power moving its own components around.
• Metal parts wear less.

There are two types of cooling systems found on cars: liquid-cooled and air-cooled.

Liquid Cooling
The cooling system on liquid-cooled cars circulates a fluid through pipes and passageways in the engine. As this liquid passes through the hot engine it absorbs heat, cooling the engine. After the fluid leaves the engine, it passes through a heat exchanger, or radiator, which transfers the heat from the fluid to the air blowing through the exchanger.

Air Cooling
Some older cars, and very few modern cars, are air-cooled. Instead of circulating fluid through the engine, the engine block is covered in aluminum fins that conduct the heat away from the cylinder. A powerful fan forces air over these fins, which cools the engine by transferring the heat to the air.