The Mercedes AMG GT 63 AMG S 4.0 V8 Bi-Turbo 640hp (2018 ->) produces 640bhp and 900Nm in standard form. Our Stage 1 ECU tuning file raises output to 680bhp and 1000Nm, a gain of 40bhp and 100Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.