Turbo Intercooler Works

A turbocharger uses exhaust energy to compress intake air and thus stuff more oxygen into the combustion chamber. More air equals more power. In this video, we can witness the path. The turbocharger's compressor wheel draws outside air from the airbox and compresses it. According to the Ideal Gas Law, an increase in density corresponds to a rise in temperature. Higher intake-air temperature reduces the efficiency of an engine, and that's where an intercooler comes in. This heat exchanger, which typically looks just like a radiator, cools the intake air.

The denser, hotter air travels from the turbo's compressor to the air-to-air intercooler (so called because it uses air to cool air). After the intercooler, the cooled—and now even denser—air travels to the intake manifold, where it's distributed to the cylinders. The injectors squirt in the fuel, the spark plug fires and the mixture burns, creating the high pressure that drives down the piston. The spent gases exit the cylinder and then drive the turbine side of the turbo, completing the cycle. When no boost is required, like when a car is coasting, a wastegate opens to allow the exhaust gases to bypass the turbo.