B58 Stage 3 Turbo Upgrade (800hp) — M140i/M240i/340i/440i/540i/740i

Fitment spans the full B58-powered F and G chassis lineup: M140i (F20/F21), M240i (F22/F23), 340i (F30/F31/F34 GT), 440i (F32/F33/F36 Gran Coupe), 540i (G30), and 740i (G11/G12), all equipped with the 2998cc B58B30 engine from May 2015 onward. The unit corresponds to OEM turbo references 8679022, 18559700063, and 18559710063, providing a clear cross-reference point for confirming compatibility with your specific build.

Each unit is factory-tested under simulated extremes — high temperature, high pressure, and sustained high-speed operation — before shipment, with the turbine blade geometry also refined to dampen operational noise compared to less refined aftermarket alternatives. That said, this is a performance-focused upgrade that demands professional installation and a supporting ECU tune to operate safely at the claimed power level. Adequate fueling, a capable intercooler, and drivetrain reinforcement are strongly advised to exploit everything this turbo can deliver reliably.

For B58 owners building toward serious power on a structured budget, this Stage 3 upgrade offers an aggressive hardware specification — billet compressor, high-flow turbine, and revised tip — at an accessible price point. Pair it with the right supporting modifications and a quality tune, and the foundation is there to push well beyond what the factory unit was ever asked to do.