Intercoolers
When air is compressed, it heats up; and when air heats up, it
expands. So some of the pressure increase from a turbocharger is
the result of heating the air before it goes into the engine. In
order to increase the power of the engine, the goal is to get more
air molecules into the cylinder, not necessarily more air
pressure.
An intercooler or charge air cooler is an additional component that
looks something like a radiator, except air passes through the
inside as well as the outside of the intercooler. The intake air
passes through sealed passageways inside the cooler, while cooler
air from outside is blown across fins by the engine cooling
fan.
The intercooler further increases the power of the engine by
cooling the pressurized air coming out of the compressor before it
goes into the engine. This means that if the turbocharger is
operating at a boost of 7 psi, the intercooled system will put in 7
psi of cooler air, which is denser and contains more air molecules
than warmer air.
