Gains are 80whp/100wtq on pump gas and up to 150whp/175tq on higher octane or E85 mixtures.
The ultimate tune for your S58 powered G87 M2, G80 M3, or G82 M4, the JB4 allows you to go from factory stock to full race and everywhere in between. The JB4 installs and removes easily and includes many unique features not found in any other tune, including user-adjustable 1st and 2nd gear boost limiting, smartphone integration, electronic wastegate control, ethanol fuel support, and built-in advanced CANbus-based diagnostic tools. Installation is easy and completely removable with no splicing or cutting of factory wires making the JB4 an excellent choice for your S58 engine.
