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The BMW M5 F90 is the most potent iteration of BMW's legendary super sedan, powered by the S63B44T4 — a 4.4-litre twin-turbocharged V8 producing 600 HP in standard trim and 625 HP in Competition spec. With boost levels held conservatively from the factory and a robust bottom-end forged rotating assembly, the S63 in the F90 is one of the most rewarding platforms in the BMW M lineup to tune. Stage 1 ECU calibration alone pushes past 700 HP, while full-build Stage 3 configurations regularly exceed 1,000 HP on pump fuel. This guide breaks down every tuning stage, the hardware each...

The BMW S63 engine family is one of the most capable twin-turbo V8 platforms ever built. From the F10 M5 to the F90 M5 Competition, and from the M6 Grand Coupé to the X5M and X6M, the S63 in its various iterations has powered BMW's most powerful models for over a decade. Upgrading the factory downpipes is the single most effective bolt-on modification across the entire S63 lineup.This guide covers catless downpipe options for every S63-powered BMW, real-world power gains, exhaust sound changes, fitment across all models, and why an ECU calibration is essential.The S63 Engine Family — Platform OverviewThe...

The BMW F90 M5 uses the S63B44T4 — a 4.4-litre twin-turbo V8 that produces 591–617 HP from the factory depending on variant. It is one of the most potent sedans ever built, and it has substantial untapped potential locked behind factory exhaust restrictions. The stock catalytic converters downstream of each turbocharger are the primary bottleneck, and replacing them with performance downpipes is the foundation of any serious M5 build. Why the S63 Needs Downpipes The S63 positions its two twin-scroll turbochargers outboard of the cylinder banks in a traditional hot-outside-vee layout. Each turbo feeds exhaust through its own catalytic converter...

Why Upgrade Downpipes on the BMW X5M / X6M?The F95 X5M and F96 X6M pack BMW’s S63TU twin-turbo 4.4L V8 producing 600–617 HP from the factory. The OEM downpipes use two close-coupled catalytic converters that create significant back-pressure. Upgrading to high-flow downpipes is the most impactful single bolt-on modification — reducing turbo spool time, increasing peak power, and giving the V8 a much more aggressive exhaust note.Catless vs 200-Cell — Comparison Table Type HP Gain (with Stage 2) Torque Gain Emissions Sound Best For Catless (race) +80–130 WHP +90–120 lb-ft Off-road / track only Very loud, deep V8 bark Max...

Catless downpipes are one of the highest-impact bolt-on modifications for turbocharged BMW engines. By removing the restrictive factory catalytic converters, exhaust gas exits the turbocharger housing with significantly less backpressure — meaning the turbo spools faster, exhaust gas temperatures drop, and the ECU has more headroom to add power when paired with a Stage 2 tune. YPG Motorsport stocks catless, 200-cell and 400-cell high-flow catted downpipes for every major BMW performance engine — from the S55 inline-6 in the M3/M4 to the S63TU twin-turbo V8 in the M5 and M6, plus the B58 single-turbo six powering the 240i through 640i...