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McLaren 570S, 650S & MP4-12C M838T ECU Tuning Guide — Stage 1, 2 & 3 Power Gains (2026)
The McLaren M838T 3.8-liter twin-turbocharged V8 is one of the most capable engine platforms in the supercar world — and it powers more McLaren models than any other engine in the company's history. Found in the 570S, 570GT, 540C, 600LT, 650S, and MP4-12C, the M838T responds to ECU calibration with gains that transform these already rapid supercars into genuinely terrifying machines. A Stage 2 tune on the 570S delivers 680 HP from an engine rated at 562 HP from the factory — and the 650S responds with similar aggression. This guide covers everything you need to know about ECU tuning...