Description
Unlock the full potential of your Toyota GR Yaris or GR Corolla with the JB4 Performance Tuner, delivering up to 50whp and 60wtq to the wheels on a stock vehicle—without the risks associated with ECU flashing. This plug-and-play tuning solution attaches to two easily accessible engine sensors, working alongside your factory DME to optimize boost, timing, and fueling for maximum performance and reduced turbo lag.
Powered by a 64MHz processor, the JB4 samples engine sensors 800 times per second using dedicated 10-bit digital-to-analog converters, ensuring smooth, responsive, and consistent power delivery. Installation is discrete and fully reversible, leaving no trace and without impacting fuel economy in normal driving conditions. Compatible with all driving modes, the JB4 requires no ECU flash.
Advanced CANbus Integration & JB4PRO App
The JB4 is fully CANbus equipped, allowing it to utilize advanced engine data for mapping, logging, and diagnostics. Monitored parameters include boost, timing, air/fuel ratio, fuel trims, throttle, knock control, and more.
With the JB4PRO wireless adapter, you can connect to your iOS or Android device to:
- Record and analyze engine and tuning data
- Change performance maps on the fly
- Update firmware with free future releases
- Access advanced logging and performance estimation tools
The adapter fits entirely inside the JB4 enclosure, providing enhanced weather protection and a streamlined look.
Features & Benefits
- Power gains of up to 50whp and 60wtq on a stock vehicle
- Improves 0-60 mph acceleration and quarter-mile times
- Multiple performance maps for different fuel types, including E85 ethanol blends
- Quick plug-and-play installation, fully reversible
- Boost-by-gear control for improved traction
- Read and clear fault codes; log up to 40 engine parameters
- Exhaust flap control on supported vehicles
- Full CANbus integration for smooth operation and advanced diagnostics
- Runs as smoothly as stock in all driving modes
- No impact on fuel economy during normal driving
- Requires 91 octane or higher for full performance gains
- Non-VIN locked and fully removable
- Durable billet aluminum enclosure
- Designed and assembled in the USA
- 5-year warranty
Vehicle Fitment
Toyota:
- 2021+ GR Yaris Turbocharged 3-cylinder
- 2023+ GR Corolla Turbocharged 3-cylinder
Why Choose JB4?
The JB4 is a true plug-and-play performance tuner for turbocharged Toyota models. By connecting to engine sensors and CANbus data, it safely optimizes boost, fuel, and timing without modifying your ECU. Fully non-VIN locked and removable, it preserves all factory safety systems while delivering smooth, reliable, and significant power gains. With over a decade of proven performance in 67+ countries, the JB4 is the gold standard for turbocharged vehicle tuning.
