How exactly does and air-to-air intercooler cool the air that goes through it? what is in the intercooler that makes it cooler?
Its works just like your radiator, except replace the water flowing through the radiator with air.
An air to air intercooler keeps the compressed air inside the intercooler, then ambient air flows over the outside of the intercooler. Fins on the inside and outside increase the surface area to transfer heat better.