The Porsche 911 4.0 GT3 RS 520hp (2016 - 2018 (991.2)) produces 520bhp and 470Nm in standard form. Our Stage 1 ECU tuning file raises output to 540bhp and 490Nm, a gain of 20bhp and 20Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.