MINI B38/B46/B48 JB4 Tuner
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.
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.
Wirelessly connect the JB4 to your Bluetooth 4.0 compatible iOS, and Android device via the JB4 Mobile connect kit or to your Windows laptop with the BMS data cable. Both options allow 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. A separate JB4 Mobile app purchase is also required.
The latest B38/B46/B48 map guide, feature set, firmware updates, and directions are posted here.
JB4 Features & Benefits
• Power gains of up to 40hp to the wheels on a stock vehicle
• Improves 0-60 times and 1/4 mile times
• Preloaded with custom JB4 tuning software and up to 8 maps for various fuel and modification levels
• Ethanol (E85) compatible tuning maps
• Able to read/delete fault codes
• View and record up to 40 different gauges/engine parameters in real-time with the JB4 app.
• Boost by gear in 1st, 2nd, and 3rd can be controlled via the JB4 app for a perfect launch
• Compatible with JB4 Mobile for smartphone logging, tuning changes, and adjustment
• The JB4 offers a lot more performance, functionality, and safety than your average performance chip
• Quick Plug & Play Installation
• CANbus OBDII integration offering unrivaled tuning features and performance
• Improved performance over non-integrated chip tunes
• Runs as smoothly as stock, this is how your vehicle should have come from the factory
• Compatible with all driving modes
• Fuel economy unchanged during normal driving
• 91 octane fuel or better required for performance gains
• Not VIN locked and can be removed without a trace and resold down the road
• Includes the rugged JB4 billet aluminum enclosure for protection
• Made in the USA
• Free USA Shipping
• 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.
