Description
JB4 Tuner for Lexus LX 600 & GX 550 – 3.5L Twin-Turbo (BETA)
Unlock exceptional performance from your Lexus LX 600 or GX 550 with the JB4 Plug-and-Play Tuner—now available in BETA for Toyota’s new 3.5L twin-turbo powerplant. Delivering gains of up to 75 wheel horsepower on a stock vehicle, the JB4 dramatically enhances acceleration, throttle response, and overall driving performance while preserving factory-smooth operation and OEM safety systems.
Engineered using advanced CANbus integration, the JB4 safely adjusts boost, ignition timing, and fuel parameters based on real-time sensor data. With up to eight selectable maps, including E85 ethanol-compatible tuning options, the JB4 adapts seamlessly to different fuel grades and performance modifications.
Monitor and log detailed engine data with the JB4 Mobile App, adjust boost-by-gear for improved traction, and diagnose your vehicle using built-in fault code reading and clearing. Best of all, installation is quick and completely reversible—no ECU flashing, no permanent modifications, and no VIN locking.
Featuring a rugged billet aluminum enclosure and backed by a 5-year warranty, the JB4 stands as the most advanced and trusted plug-and-play tuning solution available worldwide.
Key Features & Benefits
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Up to 75whp gain on stock vehicles
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Significantly improves 0–60 mph and ¼-mile performance
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Preloaded Lexus-specific tuning maps with up to 8 selectable options
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E85 ethanol-compatible tuning support
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Read and clear diagnostic fault codes directly through the JB4 app
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View and log 20+ engine parameters in real time
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Boost-by-gear control for optimized traction in 1st, 2nd, and 3rd gears
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Full JB4 Mobile App support for tuning adjustments, data logging, and monitoring
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More advanced, safer, and more capable than traditional chip tunes
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Simple plug-and-play installation
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CANbus OBDII integration for unmatched tuning precision
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Smooth, factory-like drivability in all conditions
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Compatible with all factory driving modes
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No impact on fuel economy during normal driving
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Requires 91+ octane fuel for performance maps
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Not VIN-locked—remove and resell anytime
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Heavy-duty billet aluminum enclosure included
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Proudly made in the USA
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Backed by a 5-year manufacturer warranty
Vehicle Fitment
Lexus (BETA Applications):
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2022+ Lexus LX 600 – 3.5L Twin Turbo
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2024+ Lexus GX 550 – 3.5L Twin Turbo
What Is a JB4?
The JB4 is an advanced plug-and-play tuning system designed for modern turbocharged engines. Installed between the ECU and key engine sensors, it safely modifies boost, timing, fueling, and other parameters to deliver significant power gains—all without permanently altering the vehicle’s factory programming. With CANbus integration, spark and fuel control, Bluetooth connectivity, and continuous firmware updates, the JB4 offers unmatched precision and flexibility compared to traditional piggyback chips.
Is the JB4 a Real Tune?
Yes. The JB4 provides tuning capabilities comparable to an ECU reflash by dynamically adjusting boost, ignition timing, air-fuel ratios, and fuel trims in real time. Because it works through sensor data and CANbus channels, your ECU remains unaltered and unflagged. The result is reliable, smooth, and powerful performance while retaining all built-in factory safety systems—and the ability to instantly return to stock by simply unplugging the unit.
