The Mercedes SL 63 AMG V8 BiTurbo Pack Performance 571hp (R231 - 2012 - 2015) produces 571bhp and 900Nm in standard form. Our Stage 1 ECU tuning file raises output to 660bhp and 900Nm, a gain of 89bhp, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.