The JB4 is a true user adjustable plug and play solution. Power Gains: Starting at peak 370bhp and 380ft lb.

The JB4 features CANbus connectivity for more advanced tuning, direct AFR control, advanced safety systems for boost, air/fuel ratio, fuel trims, and engine knock, boost mapping by gear for improved traction, integrated water/meth control, and much more. 

The unit can be used with our JB4 Bluetooth Connect kit providing for full in-car engine parameter display, map switching, and adjustment.

Stored maps available for 91/95ron and 93/98ron for manual and DSG

Purchase Downpipe with Tuner For Extraordinary Performance

Wirelessly Connect to your JB4: Our all-new JB4 PRO smartphone connection is included 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 information about the JB4PRO mobile app click here.

Group 18 JB4 Features & Benefits

• Up to 75hp on a stock vehicle, 50hp/65ft lbs on 91/95ron and 65hp/70ft lbs on 93/98ron
• Improves 0-60 times and 1/4 mile times
• Preloaded with custom tuning software and up to 8 maps for various fuel and modification levels
• The JB4 offers a lot more performance, functionality, and safety than your average performance chip
• Quick Plug & Play Installation
• CANbus OBDII integration offering unrivaled tuning features and performance
• Improved performance over non-integrated chip tunes
• Runs as smoothly as stock, this is how your vehicle should have come from the factory
• Compatible with all driving modes
• Fuel economy unchanged during normal driving
• Compatible with JB4 Mobile for smartphone logging, tuning changes, and adjustment
• 91 octane fuel or better required for performance gains
• Able to read/delete fault codes
• Not VIN locked and can be removed without a trace and resold down the road
• Made in the USA
• 5 year warranty

Vehicle Fitment

Volkswagen

• 2021-Present VW MK8 Golf R

Audi
• 2021-Present Audi S3 8Y
• 2021-Present Audi SQ2

Seat
• 2021-Present Seat Cupra Leon
• 2021-Present Seat Formentor

Purchase link: JB4 Tuner for 2021+ Audi A3 8Y & 2024+ VW MK8 GTI (Gen4)

What is a JB4?

The JB4 is a plug & play tune available for turbocharged vehicles. The JB4 tuner installs between your car's sensors and the 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.