S58 JB4 Performance Tuner for 2021+ BMW M3/M4 & 2023+ M2 (G80/G82/G83/G87)

Gains are 80whp/100wtq on pump gas and up to 150whp/175wtq on higher octane or E85 mixtures.

BOTH VERSIONS NOW INCLUDE THE FREE JB4PRO APP! 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.

Also available with our new JB4PRO board which includes built in Bluetooth, fuel pressure control for more advanced tuning with ethanol mixtures, built in flex fuel/port injection/WMI control using our PNP add on harness, onboard data-logging memory, and many additional features to be unlocked in the future via free firmware updates.

Includes the JB4PRO app! Wirelessly connect the JB4 to your iOS or Android device to record and analyze vehicle and tuning data, change JB4 performance maps, and update JB4 firmware as we release free newer versions with updates, more powerful maps, and new features under development.

The JB4PRO app features an intuitive easy-to-use interface, help buttons, and advanced log analysis tools that can estimate the performance of your car and help identify any tuning concerns. More information on the JB4PRO app is available here.

JB4PRO Optional Flex Fuel & Port Injection Harnesses: This harness lets you attach directly to an ethanol sensor for reading ethanol mixtures as well as connect to port fuel injectors for built in multi-stage batch fire injector control. Available here.

Optional Extension Harness: These plug and play connectors simplify the installation and removal of JB4 and other S58 piggyback systems by allowing you to bypass the difficult to reach lower MAP sensor by attaching the connections to each other.Available here.

NEW! Optional JB4 ECU CANbus Harne