JB4PRO for 2025+ C8 Chevrolet Corvette ZR1 & 2026+ ZR1X LT7 (BETA)

Power gains of up to 100whp peak and 220whp under the curve!

JB4 is finally here for your C8 ZR1 Corvette! Featuring our latest JB4PRO hardware this system attaches to easy to reach connections in the engine bay, as well as your OBDII port, to retune the LT7 for higher power and torque levels. By intercepting and altering specific sensor signals dynamically the JB4 can safely reshape your boost, timing, and AFR profiles without having to unlock the ECU or rewrite any ECU tables.

The JB4 includes several maps including a map for pump gas, race gas mix, straight race gas, up to 30% E85 mixtures, and a bypass/factory map. Using the free JB4PRO app you can change maps on the fly and make various tuning adjustments including boost limiting by gear for improved traction in lower gears, setting maximum boost safety levels, and even reshape your desired boost/torque curve manually. The JB4PRO app also includes data logging, tuning insights, performance estimates, code management, and much more, giving you full control over your tuning experience.

Note ZR1 systems are low volume and currently made to order, expect a 1-2 week delay in shipping

Includes the JB4PRO app!Wirelessly connect the JB4 to your iOS or Android device 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.

The JB4PRO 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. More information on the JB4PRO app is available here.

JB4 Features & Benefits

Power gains of up to 220whp under the curve on a stock vehicle with high octane
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 veh