biturbo RSS

The Mercedes-AMG GT family runs the M178 — the dry-sump variant of AMG's 4.0L twin-turbo V8. Like its wet-sump sibling (the M177), the M178's stock high-pressure fuel pump is the first bottleneck when pushing beyond factory output. This guide covers HPFP upgrade options specifically for the AMG GT, GTS, GTC, GTR, and Black Series. M178 vs M177 — What's Different? The M178 shares the same 4.0L twin-turbo V8 block architecture as the M177 but uses a dry-sump lubrication system instead of wet sump. This allows the engine to sit lower in the chassis for a lower center of gravity —...

The stock high-pressure fuel pump on the Mercedes-AMG M177 4.0L V8 BiTurbo is the first component to hit its limit when you push beyond factory power. Whether you're running a Stage 2 ECU calibration, upgraded turbos, or ethanol-blended fuels, the OEM HPFP cannot deliver enough volume to maintain stable rail pressure — and that means lost power, misfires, or worse. This guide covers everything you need to know about upgrading the HPFP on the M177 platform: what the stock system's limits are, how 250bar and 350bar kits compare, which models fit, and what supporting modifications you need. Why the Stock...

Audi RS4 & RS5 B9 Overview — 450 HP from the EA839 2.9T V6 The Audi RS4 Avant and RS5 (Coupe and Sportback) in B9 generation are powered by the EA839 2.9-liter twin-turbocharged V6, producing 450 HP and 443 lb-ft of torque from the factory. Power is delivered through a ZF 8HP torque-converter automatic and Audi's Quattro all-wheel-drive system, giving the RS4/RS5 a 0–60 mph time of approximately 3.7 seconds. The EA839 uses the same hot-vee architecture as the larger EA825 4.0T V8 found in the RS6, RS7, RSQ8, and Lamborghini Urus. The turbochargers sit between the cylinder banks rather...

The M157 5.5-liter twin-turbo V8 is one of Mercedes-AMG's most iconic powertrains — a hand-built engine that powered the previous-generation E63, ML63, and G63 from 2012 through 2018. With factory outputs ranging from 550 HP to 585 HP, the M157 was already formidable from the factory. But the factory catalytic converters create a massive restriction downstream of the turbochargers that limits both power delivery and turbo efficiency.This guide covers everything you need to know about upgrading downpipes on your M157-powered Mercedes: catless versus high-flow catted options, real-world power gains, exhaust sound changes, fitment across all M157 models, and why an...

Mercedes-AMG uses two versions of its hand-built 4.0-litre twin-turbo V8: the M177 and the M178. They share the same bore, stroke, and hot-inside-V turbo layout — but they are not the same engine and they are not interchangeable. If you are ordering an engine build, turbo kit, or any internal component, you need to know which one you have. This guide explains the differences. Quick Comparison M177 M178 Displacement 3,982 cc (4.0L) 3,982 cc (4.0L) Configuration 90° V8, DOHC, 32-valve 90° V8, DOHC, 32-valve Turbo layout Hot-inside-V Hot-inside-V Oil system Wet sump Dry sump Block casting M177-specific M178-specific Oil pan...