Using a HKS GT Ballistic Dual Bearing Turbo Charger and all the piping to make it work, this just may be one of the coolest turbo upgrade kits available for the 02-03 WRX! HKS GT Ball-Bearing Sport Turbo Upgrades are bolt-on turbo upgrade kits for factory turbo-charged vehicles like the 02-03 Subaru WRX. These kits consist of a new larger HKS GT turbo designed to bolt directly on to the stock manifold, but in the Subaru's case, the Up-Pipe! HKS GT Sport Turbos are designed and sized to promote maximum power and response for maximum airflow throughout the RPM band. From the HKS precision cast turbine and compressor housings to the specially designed compress blades, each turbo is crafted to provide high levels of performance and quality. You will need extra fuel tuning with this turbo upgrade kit because it will need way more fuel than your stock injectors and pump can provide. We reccomend a Walbro 255 fuel pump, perrin fuel rails, power enterprise 650cc injectors and either a UTEC or some other form of engine management for an upgrade this serious.