Ready to take your F chassis N55 BMW to the next level? How about up to 60hp to the wheels (80hp crank) on a completely stock car or up to 100hp to the wheels (120hp crank) on a fully modified car? The JB4 features a simple plug and play installation harness for easy installation and includes many features not found on any other tune. Including the ability to enable/disable the tuning from the drivers seat, gear dependent boost control to help with traction, autotuning for E85 mixtures, built in diagnostic code reading/deleting, expanded engine safety systems, free firmware updates, in dash boost gauge, the ability to control the exhaust flapper using your BC button, and much more.

The JB4 does not require any additional modifications or previous stages. Simply install the JB4 as your first and only modification and enjoy an entirely new fast and smooth racing experience. For more advanced enthusiasts the BMS DATA or JB4 Mobile cable allows you to connect a laptop or smart phone for additional gauges, data logging, and free firmware updates as we add new features and maps.

The JB4 is a fully plug and play device that installs and removes in minutes at home without special tools and unlike flash maps that permanently write over your DME with the JB4 your DME is never aware it's running more than the factory power levels. And when you're ready to change things up the JB4 is not VIN locked and can be moved to your next vehicle or resold. Made in USA. 5 Year Warranty.