JB4 Performance Tuner for Mercedes-Benz AMG
C63, E63, GT, GLC (Including S Models)

Unlock the full potential of your AMG. The JB4 Performance Tuner is the most powerful, feature-rich plug & play tuning solution available for Mercedes-Benz AMG vehicles equipped with the M178 engine. Designed to work seamlessly with your factory ECU, the JB4 delivers massive power gains, faster throttle response, and reduced turbo lag—while maintaining factory smoothness and reliability.

🔥 Power You Can Feel

• Up to +100 WHP & +100 WTQ on a stock vehicle
• Improved throttle response and reduced turbo lag
• Faster 0–60 and quarter-mile times
• Runs as smoothly as stock across all driving modes

🔌 True Plug & Play Installation

The JB4 installs in under an hour with no cutting, splicing, or permanent modifications. It connects directly to easy-to-access engine bay sensors and integrates with your factory ECU for precise, intelligent control.

• Manifold TMAP
• Charge pipe MAP
• Fuel pressure sensors (both sides)
• OBDII CANbus connection

🧠 Advanced CANbus Integration

Unlike basic “chip tunes,” the JB4 features full CANbus integration, allowing it to monitor and react to real-time engine data for unmatched performance and safety.

• Fuel control for safe high-power operation
• Advanced engine data monitoring
• Improved performance over non-integrated tuning solutions

📱 Smartphone Control & Datalogging

Pair your JB4 with a compatible Bluetooth adapter to unlock full wireless control via your iOS or Android device.

• Switch performance maps on the fly
• Datalog up to 40 engine parameters in real time
• Read & delete fault codes
• Firmware updates with new features and maps
• 0–60 performance measurement

JB4 Mobile app sold separately ($29) and requires a JB4 Bluetooth adapter.

🏁 Race-Ready Features (Exclusive to JB4)

• User-adjustable boost by gear for improved traction
• Support for pump gas, E85 blends, race fuel, and WMI
• Valet mode with reduced power
• Exhaust flap control on most applications

⚙️ Optional Boost Control Module (BCM)

For vehicles running aggressive bolt-ons, WMI, upgraded turbos, or high-octane fuel, the optional Boost Control Module (BCM) allows direct wastegate control for increased boost targeting.

• Required for higher-than-stock wastegate duty cycles
• Plugs directly into JB4 harness and boost solenoid
• Estimated price: $199 (sold separately)

✅ JB4 Features & Benefits

• Up to 8 preloaded performance maps
• Ethanol (E85) compatible tuning
• Boost-by-gear control (1st, 2nd, 3rd)
• Fuel economy unchanged during normal driving
• 91 octane or higher recommended
• Not VIN locked – transferable or resellable
• Removable with no trace
• Rugged billet aluminum enclosure
• Made in the USA
• 5-Year Warranty

🚗 Vehicle Fitment (M178 Engine)

C-Class

• 2015+ Mercedes-Benz C63 AMG
• 2015+ Mercedes-Benz C63 S AMG

E-Class

• 2017+ Mercedes-Benz E63 AMG
• 2017+ Mercedes-Benz E63 S AMG

AMG GT

• 2015+ AMG GT
• AMG GT S
• AMG GT R
• 2018+ AMG GT 63 & GT 63 S

GLC

• 2015+ Mercedes-Benz GLC 63 AMG
• 2015+ Mercedes-Benz GLC 63 S AMG

❓ What Is a JB4?

The JB4 is a proven plug & play tuning system for turbocharged vehicles that installs between your engine sensors and ECU. By intelligently manipulating boost, fuel, and timing—while monitoring real-time CANbus data—the JB4 delivers massive performance gains with factory-like drivability.

Often imitated but never duplicated, the JB4 has been the gold standard in plug & play turbo tuning for over a decade and is trusted by enthusiasts in over 67 countries worldwide.