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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 driver's 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 Tuner 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 smartphone for additional gauges, data logging, and free firmware updates as we add new features and maps.
The JB4 is a full 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 the USA. 5 Year Warranty.
Note for electronic wastegate models, the EWG add-on connector remains optional and can be purchased separately from our upgrades for higher HP applications where direct EWG control is beneficial, such as those using an integrated WMI kit or larger turbo.
NOTE: Some F10 and X chassis models require a JB4PRO bluetooth adapter to select options bit#1 in the FREE JB4PRO app to enable the in-dash controls for those models.
Click here for the latest JB4 firmware, map guide, and details
Wirelessly Connect to your JB4: Grab our all-new JB4 PRO smartphone connection to wirelessly connect the JB4 tuner to your Bluetooth 4.0 compatible iOS or Android device. This option allows 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. Our new adapter fits fully inside the JB4 enclosure for enhanced weather protection and a more streamlined look. The JB4PRO Free app features an intuitive easy-to-use interface, help buttons, and advanced log analysis tools that can estimate the performance of your car and help identify any tuning concerns. For more info on how to use the JB4PRO free app click here.
BMW 1 Series
BMW 2 Series
BMW 3 Series
BMW 4 Series
BMW 5 Series
BMW 6 Series
BMW 7 Series
BMW X Series
- Purchase E Chassis N55 JB4
Warranty & Support: The JB4 tuner comes with a 5-year warranty and is made in the USA, reflecting its durability and commitment to quality. Users can also benefit from free USA shipping.
Overall, the JB4 is a comprehensive tuning solution, perfect for enhancing performance while maintaining safety, drivability, and convenience for a broad spectrum of F-Chassis N55 BMW vehicles.
Wastegate Identification Chart. Pneumatic (PWG) or Electronic (EWG)?
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.
Yes the JB4 is a real tune. By tapping into specific sensors and CANbus for real time vehicle data the JB4 is able to alter your boost, timing, AFR, and/or fuel trims, to a similar degree an ECU reflash would, but without the vehicle ever knowing its been tuned. The result is safe, smooth, and significant power and torque gains while retaining your factory safety systems and without having to unlock/flag your ECU.
DYNO RESULTS

F22 M235i with intake, exhaust

F30 335i with BMS intake, exhaust

Change maps on the fly
Control your roar! Open and close your exhaust flapper valves.
JB4 N55 435i EWG install video
JB4 N55 335i/335iX PWG install video
JB4 N55 BMW F10 535i/535iX install video
Ships within 48 hours · Estimated delivery Jun 21 - Jun 26
US$40
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