An intercooler's primary function is to cool the charge air after it has been heated due to boosting and the heat that is produced by the turbo before sending the air into the engine. As the air is cooled, it becomes denser, and denser air makes for better combustion (more power). Additionally, the denser, cooler air helps reduce the chances of knock. Precision Turbo & Engine Intercoolers Thank you for shopping Manic Tech Racing.