Perrin 08+ WRX/STi FMIC Black Core and BeamPSP ITR 430 1BK A key to making more power on any turbocharged engine is the addition of a high performance air to air intercooler. This part in the simplest of terms, cools the air going from the turbo into your engine, much the same as a radiator cools the water inside the engine, by transferring the excess heat way using multiple passages through a core. A PERRIN intercooler fits easily to the front of your Subaru to maximize cooling. *Intercooler