BMS JB4, engine tuning device BMW S58 2021+ BMW M3 / M4 and G87 M2

BMS JB4 Tuning Controller – BMW N20 / N26 Engines

The BMS JB4 is the most advanced plug-and-play tuning controller available for BMW N20/N26 engines, offering impressive performance gains, enhanced drivability, and full Bluetooth app support. Working in parallel with the factory ECU, the JB4 adjusts boost, fuel, and performance parameters in real time without flashing or modifying the original software.

With multiple preset maps, data logging, autotuning features, and optional E85/flex-fuel support, the JB4 provides a flexible and safe tuning solution suitable for both daily driving and track use. It is fully removable without leaving a trace, making it ideal for warranty-sensitive vehicles.

Features & Benefits

• Gains of up to ~60hp depending on fuel quality and modifications
• Plug-and-play installation—no ECU flash required
• Multiple tuning maps for 95E, 98E, and E85 blends
• Bluetooth support via JB4 Mobile App
• Advanced CAN integration for smooth power delivery
• Custom map tuning & full data logging
• Safety systems: boost safeties, lean protection, fuel trim monitoring
• Completely removable for dealer visits

Vehicle Fitment

BMW 1 Series
F20/F21 114i / 116i / 118i / 120i (N13/N20/N26) F20/F21 125i (N20/N26)

BMW 2 Series
F22/F23 220i / 228i (N20/N26)

BMW 3 Series
F30/F31 320i / 328i (N20/N26)

BMW 4 Series
F32/F33/F36 420i / 428i (N20/N26)

BMW X Series
F25 X3 20i / 28i (N20/N26)

What’s Included

• JB4 N20/N26 control unit
• Plug-and-play wiring harness
• Integrated Bluetooth Connect Kit
• Installation hardware

For more details, visit the manufacturer page: Burger Motorsports

Download installation instructions here: Installation Guide