Description
Unlock the full performance potential of your 2025+ Land Rover Defender OCTA with the JB4 Tuner. Designed specifically for the 4.4L V8 Twin Turbo engine, the JB4 delivers up to 125 wheel horsepower (whp) on pump gas and up to 260 whp on higher octane fuel or E85 blends. Whether you’re seeking street performance or full race capability, the JB4 allows you to tune your vehicle anywhere from factory stock to aggressive performance levels—all with a simple plug-and-play installation.
Advanced Features and Technology
The JB4 Tuner now comes with the JB4PRO adapter and integrated free smartphone app, offering wireless connectivity and real-time control. Its innovative design leverages CANbus-based diagnostics, electronic wastegate control (under development), and user-adjustable boost limits for 1st and 2nd gear. The system supports multiple fuel types, including ethanol blends, and installs without splicing or cutting factory wires. No ECU flash is required, and it works with locked ECUs, making it fully removable and transferable.
Seamless Smartphone Integration
Connect wirelessly via Bluetooth 4.0 to iOS or Android devices using the JB4PRO app. This intuitive interface allows users to:
- Record and analyze vehicle performance and tuning data
- Switch between performance maps for different fuel types
- Update firmware and access free performance enhancements
- Utilize advanced log analysis to optimize and diagnose your setup
Performance Benefits
- Boosts 0-60 and quarter-mile acceleration times
- Provides multiple tuning maps tailored for various fuels
- Improves traction with gear-based boost control
- Reads and clears fault codes
- Displays and logs up to 40 engine parameters
- Controls exhaust flap operation on compatible vehicles
- Maintains smooth stock-like operation across all driving modes
- No negative impact on fuel economy under normal driving
Quality and Reliability
Housed in a durable billet aluminum enclosure and proudly designed and assembled in the USA, the JB4 comes with a 5-year warranty. Its fully removable, plug-and-play design ensures your Defender remains factory-compliant when needed.
Vehicle Fitment:
- 2025+ Land Rover Defender OCTA 4.4L V8 Twin Turbo
What Makes JB4 Unique?
The JB4 stands apart from traditional tuning solutions by offering advanced CANbus integration, fuel and spark control, and smartphone connectivity. Unlike VIN-locked or ECU-flashing systems, it allows safe, reversible tuning without compromising factory safety systems. Over a decade of innovation and continuous free updates have made JB4 the global standard in plug-and-play performance tuning for turbocharged vehicles, with availability in over 67 countries.
