Bolt On Mods RSS
Mercedes-AMG E63 S W213 Downpipe Guide — Catless vs 200-Cell, M177 Power Gains, Sound & Installation (2026)
The downpipe is the single highest-impact bolt-on modification you can make to the Mercedes-AMG E63 and E63 S. On the M177 4.0-liter twin-turbo V8, the factory catalytic converters sit directly downstream of the turbochargers — creating a massive restriction right where exhaust gas velocity is highest. Replacing them with aftermarket downpipes is how you go from a fast sedan to a 10-second quarter-mile car.This guide covers everything you need to know before buying downpipes for your W213 E63: catless versus 200-cell high-flow cats, real-world power gains, exhaust sound changes, fitment across all body styles, installation, and why a Stage 2...
BMW M3 F80 & M4 F82 Downpipe Guide — Catless vs 200-Cell vs 400-Cell GESI, S55 Power Gains, Sound & Installation (2026)
The S55 twin-turbo inline-six responds to downpipes harder than almost any other mod you can bolt on. On the BMW M3 F80 and M4 F82, the factory catalytic converters sit immediately downstream of the twin-scroll turbochargers — creating a restriction right where exhaust gas velocity peaks. Replace them with aftermarket downpipes, pair with a Stage 2 ECU calibration, and you're looking at 500+ WHP from a 3.0-liter six-cylinder. This guide covers everything you need to know before buying downpipes for your F80 M3 or F82/F83 M4: catless versus 200-cell versus 400-cell GESI high-flow cats, real-world dyno numbers, exhaust sound changes,...