Power gains of up to 75hp on a stock vehicle without the risks of flashing!

Now includes the JB4PRO adapter and free app built in!The JB4 is the most advanced and highly featured tuning system available for your 2018-Present Lexus LS 500 3.5L. Power gains are up to 60hp to the wheels (75hp crank) on a completely stock car on pump gas, gains with bolt-on parts, higher octane, E85 mixtures, and larger turbos are even higher.

The JB4 features a simple plug and play installation harness for easy installation & removal and includes many features not found with any other tune. Including on the fly in dash map switching between factory and various performance maps, boost limiting by gear for improved traction in lower gears, built-in data logging, built-in code reading, and much more.

Remember 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. The JB4 also does not require any user setup or customization but for those who are interested in logging, adding new features as we post them, changing maps, etc, we suggest the BMS DATA cable or the bluetooth mobile phone adapter.

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 & Benefits

• Power gains of up to 75hp 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

Lexus
• 2018+ Lexus LS 500 3.5L V6 Twin Turbo

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 it's 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 and is sold in over 67 countries worldwide.

Is the JB4 a real tune?

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.

Lexus LS 500 dyno results - JB4 Tuned vs. Stock