The Porsche 911 Carrera S 3.8i 400hp (2011 - 2015 ( 991 )) produces 400bhp and 440Nm in standard form. Our Stage 1 ECU tuning file raises output to 440bhp and 460Nm, a gain of 40bhp and 20Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.