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

BOTH VERSIONS NOW INCLUDE THE FREE JB4PRO APP! The ultimate tune for your S58 powered F97 X3M & F98 X4M, 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.

Optional Flex Fuel & Port Injection Harnesses: This harness lets let 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.

• Gains are 80whp/100wtq on pump gas and up to 150whp/175wtq on higher octane or E85 mixtures.
• 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 X3M
• 2020+ S58 F97 BMW X3M
• 2020+ S58 F97 BMW X3M Competition

BMW X4M
• 2020+ S58 F98 BMW X4M
• 2020+ S58 F98 BMW X4M Competition

Click here for S58 G8x M3/M4 JB4

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 (computer) and manipulates vehicle performance through these connections making your vehicle much faster. While it's not the only tuning system that operates this way, the JB4 separates itself from the competition with much more advanced connection points and processing, including CANbus, fuel & spark control, Bluetooth to your smartphone, and a variety of innovative and advanced features not possible with any other system. BMS regularly publishes free mapping and firmware updates adding performance and features as ongoing development allows. In addition, the JB4 system is not VIN-locked to your vehicle and can quickly be removed and swapped between cars or resold at a later time. Often imitated but never duplicated the JB4 has been the gold standard in plug and play turbocharged performance tuning for over a decade and is sold in over 67 countries worldwide.

Is the JB4 a real tune?
Yes the JB4 is a real tune. By tapping into specific sensors and CANbus for real time vehicle data the JB4 is able to alter your boost, timing, AFR, and/or fuel trims, to a similar degree an ECU reflash would, but without the vehicle ever knowing its been tuned. The result is safe, smooth, and significant power and torque gains while retaining your factory safety systems and without having to unlock/flag your ECU. 

JB4 is compatible with factory over-the-air software updates. 
Unlike flash tunes, which can be erased during an iDrive or dealer software update, JB4 does not overwrite the factory ECU software.

DRAGY TIMES