S58 JB4 Tuner for 2021+ BMW G80 M3, G82 G83 M4, & 2023+ G87 M2

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. Availalble here.

S58 JB4 Features & Benefits

• Power gains up to 150whp/175wtq
• Improves 0-60 and quarter mile times.
• Includes multiple tuning maps for different fuel types.
• Quick plug and play installation.
• Supports E85 ethanol blends.
• Reads and deletes fault codes.
• Displays and logs up to 40 engine parameters.
• Boost by gear control for improved traction.
• Controls exhaust flap operation on supported vehicles.
• Compatible with the free JB4PRO app.
• Offers better performance and safety than basic chip tunes.
• Full CANbus integration.
• Runs as smoothly as stock.
• Compatible with all driving modes.
• No impact on fuel economy during normal driving.
• Requires 91 octane or better for performance gains.
• Not VIN locked and fully removable.
• Includes billet aluminum enclosure.
• Designed and assembled in the USA.
• 5-year warranty.

S58 JB4 Vehicle Fitment

BMW M2
• 2023+ S58 G87 BMW M2

BMW M3
• 2021-2026 S58 G80 BMW M3
• 2021-2026 S58 G80 BMW M3 Competition

BMW M4
• 2021+ S58 G82 BMW M4
• 2021+ S58 G82 BMW M4 Competition
• 2023+ S58 G82 BMW M4 CSL
• 2022+ S58 G83 BMW M4 Convertible

What is a JB4?
The JB4 is a plug & play tune available for turbocharged vehicles. The JB4 tuner installs between your car's sensors and its DME/ECU and manipulates vehicle performance through these connections making your vehicle much faster. The JB4 separates itself from the competition with more advanced connection points and processing, including CANbus, fuel & spark control, Bluetooth connectivity, and a variety of innovative and advanced features. The system is not VIN-locked and can quickly be removed, swapped between cars, or resold later.

Is the JB4 a real tune?
Yes. By tapping into specific sensors and CANbus for real-time vehicle data the JB4 can alter boost, timing, AFR, and fuel trims similar to an ECU reflash, while retaining factory safety systems and without unlocking or flagging the ECU.

2022 M4 Competition with S58 JB4, E50 fuel, Fuel-It! Port Injection, BMS Intake and Locked ECU

G80 M3 JB4 tuned 1/4 mile (stock turbos)

G80 M3 JB4 tuned 1/4 mile (stock turbos)

G80 M3 JB4 Dyno, 30% E85 fuel, JB4, BMS S58 Intake

2024 G87 BMW M2 Dyno Results