JB4 Plug-and-Play Performance Tuner – Mercedes-Benz C43 AMG, E43, GLC43, SLC43, & GLE43

The JB4 Performance Tuner is the most advanced plug-and-play tuning system available for the Mercedes-Benz M276 platform. It safely increases boost, optimizes timing and fueling, and delivers strong horsepower and torque gains while maintaining factory-smooth drivability.

Proven Power Gains

• Up to +80–100 WHP on C43 / GLC43 / GLE43 models
• Strong gains on C400, C450, E400, and CLS400 platforms
• Even higher results possible with supporting mods, race fuel, or E85 blends

Boost is safely increased by approximately 3–6 PSI, with timing and fueling intelligently managed for reliability.

True Plug & Play Installation

• Installs in minutes using easy-to-access connections on top of the engine
• No cutting, splicing, or permanent modifications
• Fully reversible and leaves no trace when removed
• Compatible with both AWD and RWD vehicles

Advanced CANbus Integration

Unlike basic piggyback devices, the JB4 uses full CANbus OBDII integration to monitor real-time engine data and make intelligent adjustments for smoother, safer performance.

• Fuel and spark control for high-power operation
• Better drivability than non-integrated chip tunes
• Optional BCM support for advanced boost control

Smartphone Control & Datalogging

• Change maps on the fly via iOS or Android
• View and log up to 40 engine parameters in real time
• Read and clear diagnostic fault codes
• Firmware updates and new maps available over the air

JB4 Mobile app sold separately. Bluetooth adapter required.

Exclusive JB4 Features

• Up to 8 preloaded tuning maps
• E85 / ethanol compatible maps
• User-adjustable boost-by-gear
• Valet mode with reduced power
• Exhaust flap control on supported vehicles

Exact M276 Compatibility

• C-Class: C400, C450, C43 AMG (W205)
• E-Class: E400, E43 AMG (W213)
• CLS: CLS400 (C218 / C257)
• GLC: GLC43 AMG (X253)
• GLE / ML: GLE43 AMG, GLE450, ML400
• Other: SLC43, SL400, S400 / S450 (select models)

2019+ models use updated SENT pressure sensors and require the correct JB4 version. Please confirm your vehicle details when ordering.

Optional Supporting Mods

This listing includes optional add-ons:

• Downpipes: Raw stainless, ceramic coated, or heat-shielded
• High-Flow Filters: K&N, AFE, or BMC

Key Benefits

• Noticeably stronger acceleration and mid-range pull
• Fuel economy remains largely unchanged during normal driving
• 91+ octane recommended
• Not VIN-locked — transferable or resellable
• Rugged billet aluminum enclosure
• Made in the USA
• 5-Year Manufacturer Warranty

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