Gains are up to 80whp/100tq on pump gas and up to 120whp/140wtq on higher octane or E85 mixtures without the risks of flashing!

The ultimate tuner for your S55 powered vehicle, the JB4 allows you to go from factory stock to full race, and everywhere in between with the push of a button on your steering wheel or phone. 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, map switching in dash, electronic wastegate control, ethanol fuel support, and built-in advanced CANbus based diagnostic tools. In addition, installation is completely removable with no splicing or cutting of factory wires.

No ECU flash needed and compatible with locked 🔒 ECUs

The JB4 is compatible with the factory flash map, competition package flash map, all off-the-shelf flash maps, custom tuned flash maps, or any flash map you choose to load! For those who don't mind flashing BMS provides free back end flash maps designed to optimize performance for specific builds and fuels saving you hundreds of dollars and many hours of time on custom flash tuning.

For the latest performance results, updates, firmware, and map guide click here.

For those running aftermarket turbocharger systems with aftermarket Tial wastegate(s) we have a special version of the S55 JB4 specifically to control them. Please email us so we can manually invoice you for the JB4_S55_TIAL version.

JB4 Features & Benefits

• Gains are 80whp/100tq on pump gas and up to 120whp/140wtq on higher octane or E85 mixtures.
• Improves 0-60 times and 1/4 mile times
• Preloaded with custom JB4 BMW 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
• Designed and assembled in the USA
• 5 year warranty

S55 JB4 Vehicle fitment

BMW M2
• 2018-2022 S55 BMW F87 M2 Competition (S55 engine only)
Click here for N55 powered M2

BMW M3
• 2015-2020 S55 BMW F80 M3

BMW M4
• 2015-2020 S55 BMW F82 F83 M4, M4 GTS, M4 CS