The Dodge Challenger SRT8 6.1 V8 425hp (2008 ->) produces 425bhp and 570Nm in standard form. Our Stage 1 ECU tuning file raises output to 445bhp and 590Nm, 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.