The Holden Monaro 5.7 V8 306hp (2001 - 2005) produces 306bhp and 460Nm in standard form. Our Stage 1 ECU tuning file raises output to 325bhp and 480Nm, a gain of 19bhp and 20Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.