This brief article explains the importance of using a JB4 even if your BMW is already Flash Tuned. It specifically explains N54 applications but it mostly applies to all engines.


1- Advanced Safety system

  • If boost exceeds your safety settings, the JB4 reverts to the stock map
  • If AFR is too lean (15% variance), JB4 reverts to the stock map
  • Extra safety for Port Injection and WMI




2- Absolute Boost Control System

  • JB4 targets an absolute boost level where boost is always the same (Independent of external factors)
  • JB4 has ability to set max boost per gear
  • JB4 automatically tunes Wastegates and fuel trims
  • Autotune maps that gives max safe power based on mods, fuel, and IAT (Intake Air Temperature)


3- On The Fly Changes

  • Boost Levels
  • Max boost per. gear
  • Gauges




4- Better Feedback for the Driver

  • Ability to change ANY settings, map, gauges using the JB4 app (on phone) without the need for laptop connectivity
  • Ability to monitor real time boost, AFR timing, knock, and meth flow
  • Ability to data log and email it to BMS using the mobile app (without the need for any cable)
  • Ability to record data, 250x per second




5- Complete Tuning System

  • Eliminates need for additional modules
  • No lift shift
  • 2 step
  • Anti-Lag
  • Port Injection Control
  • Flex-Fuel sensors
  • Water/Methanol Control
  • Ability to work as a cohesive unit rather than have multiple modules working separate




6- FREE Upgrades and Support

  • Lifetime Firmware Upgrades and Backend Flashes
  • Free support from the BMS team




7- No Change In DME

  • All DME table values stay intact
  • JB4 adds performance and safety while keeping DME 100% in charge




Thank you to 'BMW Fanatic' on YouTube for the awesome explanation!
https://youtu.be/fQ39N2SpPMc