The Mercedes SL 63 AMG V8 BiTurbo 537hp (R231 - 2012 - 2015) produces 537bhp and 800Nm in standard form. Our Stage 1 ECU tuning file raises output to 660bhp and 900Nm, a gain of 123bhp and 100Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.