JB4 Tuner for F9x M5/M8/X5M/X6M

Power gains of up to 80hp and 100tq to the wheels on a stock vehicle without the risks of flashing!

The ///M JB4 takes everything that is great about the all-wheel-drive F9x M5 & M8 platform and amps it up to the next level. Power gains of up to 80whp and 100wtq bring the car to life allowing 1/4 mile potential deep into the 10s. Unlike other generic tuning devices, the JB4 includes full CANbus integration via the OBDII port for advanced tuning, safety features, and diagnostics, as well as electronic wastegate control for superior boost targeting. This is simply the best tuning box available for your //M. 

Installation is fully reversible attaching to the TMAP sensors and OBDII port. The included electronic wastegate (EWG) wires are optional and allow the JB4 to take direct control of the wastegates for more precise boost targeting for higher boost maps. Firmware update loaded via JB4 Mobile or a BMS Data Cable will be provided free of charge as we expand the JB4's performance, maps, and features with future development.

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. Separate JB4 Mobile app purchase also required.



JB4 Features & Benefits

• Power gains of up to 80hp and 100tq 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 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

M5 Series
• 2018-Present BMW F90 M5, M5 Competition, and CS

M8 Series
• 2020+ BMW F92 M8 Coupe and M8 Competition 
• 2020+ BMW F93 M8 Gran Coupe
• 2020+ BMW F91 M8 Convertible

MX Series
• 2020+ BMW X5M and X5M Competition 
• 2020+ BMW X6M and X6M Competition

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.