The Porsche Boxster GT4 4.0 420hp (2016 -> (718)) produces 420bhp and 420Nm in standard form. Our Stage 1 ECU tuning file raises output to 440bhp 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.