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.