The Porsche 911 GT3 3.8i 475hp (2011 - 2015 ( 991 )) produces 475bhp and 440Nm in standard form. Our Stage 1 ECU tuning file raises output to 500bhp and 470Nm, a gain of 25bhp and 30Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.