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. Installation is completely removable with no splicing or cutting of factory wires.

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 be sure to visit N54tech.com.

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

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

• 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 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

S55 JB4 Applications

BMW M2 
• 2018 2019 2020 M2 Competition (S55 Engine)

BMW M3 
• 2015 2016 2017 2018 2019 F80 M3

BMW M4
• 2015 2016 2017 2018 2019 F82 F83 M4, M4 GTS, M4 CS 

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.

S55 BMW M3/M4 JB4 Map Guide
Map 0: Disable JB4 / Full Pass Through Mode
Map 1: Stage1 map adding approximately 40whp and 40wtq across the power band on pump gas. Suitable for all stages and fuel mixtures.
Map 2: Slightly more aggressive version of map 1 intended for vehicles with exhaust modifications and 93+ octane fuel. Can also be used with E85 and racing fuel mixtures.
Map 3: Slightly less aggressive version of map 1 intended for vehicles running on lower grade fuels such as 91 octane.
Map 4: OEM performance but with JB4 active for diagnostics only.
Map 5: //M low torque / linear throttle map.
Map 6: Custom tuning map.
Map 7: Race gas map. Requires 100 octane unleaded fuel and for the fuel mass connector to be installed. This map can also be used with up to 35% E85.
Map 8: Methanol injection map. Requires BMS FSB controller or methanol kit for progressive mapping and safety systems.

Install Guide: https://www.n54tech.com/instructions/s55_jb4_install.pdf