The Porsche 911 4.0 GT3 RS 500hp (2011 - 2015 ( 991 )) produces 500bhp and 460Nm in standard form. Our Stage 1 ECU tuning file raises output to 525bhp and 485Nm, a gain of 25bhp and 25Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.