The Porsche Cayman GT4 3.8i 385hp (2013 - 2015 ( 981 )) produces 385bhp and 420Nm in standard form. Our Stage 1 ECU tuning file raises output to 405bhp and 440Nm, 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.