Models: Subaru Forester (SF,SG,XT), Subaru Impreza (GC8,STI,WRX), Subaru Legacy (GT)

As opposed to the single-exhaust entry turbine housing on the previous GDB model, the newer GDB STi have a twin-entry design, created for smoother exhaust gas entry to the turbine housing without having exhaust interference. The Zero/Sports AR25 Turbo allows for improved torque response from low to mid ranges. The Turbo is drastically improved by utilizing a ball bearing design and a 70φ compressor wheel that easily supports 400+ of horsepower and consistent power throughout the entire RPM range.