The N55 PWG JB4 is by far the most advanced tuning box available for the platform. The N55 PWG JB4 connects to your MAP, TMAP, Pneumatic Waste Gate, Fuel rail and OBD as standard. With the OBD connection, the JB4 has access to real time engine which it uses for tuning, logging and also safety. No other M135i PWG tuning box on the market uses real time canbus data, or has the safety systems like the JB4. If the JB4 detects any engine parameters going wrong, it will revert to a safety map.

The M135i PWG JB4 mas multiple maps to support all levels of tune. Maps and firmware are regularly updated and enhanced, which you can download for via either by the optional USB data cable or Bluetooth connector for free. Maps include and can support hardware for stage 1, stage 2, stage 3 and even methanol injection. 

With the optional meth kit, the JB4 has fully integrated meth mapping and safety. For example, if the JB4 detects low meth flow, it will automatically revert to a low boost safety map, preventing any dangerous engine knock.

The JB4 has many other features as well as those for tuning. These include datalogging, code read/writing, can flap control, boost by gear control, stacking with flash tunes, and much more!

The M135i JB4 tuning box is compatible with the M135i PWG.

Full install and map guides can be found on N54tech.com