The Subaru Impreza 2.5T WRX STI 300hp (2008 ->) produces 300bhp and 407Nm in standard form. Our Stage 1 ECU tuning file raises output to 330bhp and 467Nm, a gain of 30bhp and 60Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.