Power gains of up to 100HP to the wheel on a stock Supra without the risks of flashing!

The JB4 tuner for the Toyota GR Supra Mk5 is the most advanced plug and play tuning system available for the turbocharged Supra platform. Power gains of up to 80 horsepower to the wheels (100hp crank) are possible on a completely stock vehicle running pump gas with the B58 engine. Vehicles equipped with bolt-on upgrades, higher octane fuel, E85 mixtures, or upgraded turbochargers can achieve even greater gains. Now includes the JB4PRO adapter and free app built in!

No ECU flash required and fully compatible with locked 🔒 ECUs.

The JB4 features a simple plug and play installation harness allowing fast installation and removal while delivering advanced tuning capabilities unavailable with other tuning systems. Features include map switching between stock and performance maps, optional boost gauge displays, boost-by-gear control for improved traction, progressive water/methanol integration, built-in data logging, fault code reading and clearing, optional electronic wastegate control, exhaust flapper control, and many additional advanced tuning features.

Unlike ECU flash tunes, the JB4 requires no staged upgrades or supporting modifications. Install it as your first upgrade and immediately experience stronger acceleration, faster turbo response, and smoother power delivery.

Note: In-dash commands have not yet been developed for the Supra JB4. 

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.

JB4 Features and Benefits

• Power gains of up to 100 horsepower to the wheels on a stock vehicle
• Improves 0-60 and quarter mile times.
• Includes multiple tuning maps for different fuel types.
• Quick plug and play installation.
• Supports E85 ethanol blends.
• Reads and deletes fault codes.
• Displays and logs up to 40 engine parameters.
• Boost by gear control for improved traction.
• Controls exhaust flap operation on supported vehicles.
• Compatible with the free JB4PRO app.
• Offers better performance and safety than basic chip tunes.
• Full CANbus integration.
• Runs as smoothly as stock.
• Compatible with all driving modes.
• No impact on fuel economy during normal driving.
• Requires 91 octane or better for performance gains.
• Not VIN locked and fully removable.
• Includes billet aluminum enclosure.
• Designed and assembled in the USA.
• 5-year warranty.

Vehicle Fitment

Toyota GR Supra Mk5

• 2020-2026 Toyota GR Supra Mk5 B58 3.0L inline-6
• 2020-2026 Toyota GR Supra Mk5 B48 2.0L turbo 4-cylinder

What is a JB4?

The JB4 is a plug and play performance tuner designed for turbocharged vehicles. It installs between the engine sensors and the factory ECU allowing it to safely manipulate boost pressure, ignition timing, and fueling to deliver substantial horsepower gains while retaining factory safety systems.

The JB4 separates itself from other tuning systems with advanced CANbus integration, smartphone connectivity, ethanol compatibility, and continuous firmware updates that expand features and performance over time.

The JB4 system is not VIN locked and can easily be transferred to another vehicle or resold later. The JB4 has been the gold standard in plug and play turbocharged tuning for over a decade and is used in more than 67 countries worldwide.

Is the JB4 a real tune?

Yes. The JB4 actively adjusts boost pressure, ignition timing, air-fuel ratios, and fuel trims using real-time engine data through its CANbus connection. This allows the JB4 to deliver performance gains similar to ECU flash tuning without permanently modifying the ECU.

2022 Toyota Supra shown with BMS Billet Strut Braces, BMS Intake, and BMS B58 Billet Oil Filter Cap.

Dyno Results

2020+ Toyota Supra Mk5 Dyno Results

Supra JB4 Installation Video

The JB4 is simply the best plug and play tuner for your Toyota GR Supra Mk5.