Ready to take your MINI B38/B46/B48 turbo to the next level?

The JB4 is the most advanced and highly featured tuning system available for your B38/B46/B48 MINI. Power gains are up to 40hp to the wheels (55hp crank) for a B48. Gains with bolt-on parts, higher octane, E85 mixtures, and larger turbos are even higher. The JB4 features a simple plug and play installation harness for easy installation and includes many features not found on any other tune. Including on the fly in dash map switching between factory and various performance maps, optional in dash gauge displays for boost, boost limiting by gear for improved traction in lower gears, E85 fuel support, progressive water/methanol support, built-in data logging, built-in code reading, and much more.

Now includes the JB4PRO adapter and free app built in!

No ECU flash needed and compatible with locked 🔒 ECUs

Remember the JB4 does not require any additional modifications or previous stages. Simply install the JB4 as your first and only modification and enjoy an entirely new fast and smooth racing experience. The JB4 also does not require any user setup or customization, but for more advanced enthusiasts, the BMS DATA cable allows you to connect via a laptop for data logging and free software updates. Made in the USA. 5 year warranty.

The latest B38/B46/B48 map guide, feature set, firmware updates, and directions are posted here.

Wirelessly Connect to your JB4: Our all-new JB4 PRO smartphone connection is included to wirelessly connect the JB4 tuner to your Bluetooth 4.0 compatible iOS or Android device. This option allows you 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. Our new adapter fits fully inside the JB4 enclosure for enhanced weather protection and a more streamlined look. The JB4PRO Free 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. 

For more information about the JB4PRO mobile app click here.

JB4 Power Gains, Features & Benefits

• Power gains of up to 40hp to the wheels.
• 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.

Vehicle Fitment

MINI B38/B46/B48
• 2014-2023 F57 MINI Cooper S
• 2015-2023 F57 MINI Cooper JCW GP
• 2014-2023 F55/F56 MINI Cooper S
• 2015-2023 F55/F56 MINI Cooper JCW
• 2018-2023 F55/F56 MINI Cooper One

• 2017-2023 F60 MINI Countryman S including ALL4
• 2018-2023 F60 MINI Countryman JCW ALL4

• 2016-2023 F54 MINI Clubman S
• 2017-2023 F54 MINI Clubman S ALL4
• 2017-2023 F54 MINI Clubman JCW ALL4

If you don't see your B38/B46/B48 powered MINI or year listed here, please email us.

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.