BMW F10 550i N63 / N63TU 3" Catless Downpipes

Take your N63/N63TU 4.4L twin-turbo V8 550i to the next level with the ARM 3" Catless Downpipes. Built from full 304 stainless steel, they remove the restriction of the OEM converters, cutting back-pressure so the turbos spool faster and power and torque climb across the rev range — while unlocking an incredible exhaust note.

Highlights

• Gains of up to +43 whp / 48 wtq.
• Improved turbo spool and an enhanced exhaust note.
• Fully reversible.

Dyno proven

On an N63-equipped 2012 550i GT xDrive with a Stage 2 tune (baseline 412 awhp / 482 awtq), the ARM 3" downpipes plus cold air intake added 48 whp and 43 wtq — for a total of 460 awhp / 525 awtq.

Construction

Full 304 stainless, 3" construction following the OEM flow path for factory-precise fitment. A flex section plus upper and lower brackets (engine block and transmission housing) relieve turbo stress, and two O2 bungs per downpipe retain factory O2 placement, heat shields and correct DME data.

CEL Delete Kit

Catless downpipes will trigger a check-engine light. The optional CEL Delete Kit uses two calibrated O2 sensor spacers in the post-cat bungs to clear it without tuning it out.

Fitment (N63/TU 4.4L, slip-fit OEM downpipe only)

BMW F01/F02 750i & 750Li, F06 650i, F07 550i, F10 550i, F12/F13 650i (incl. xDrive), Alpina B6 & B7.

What's included: ARM N63 3" catless downpipes, crush brackets, hardware kit.

Backed by ARM Motorsports' lifetime warranty against defects in craftsmanship and fitment.

Emissions disclaimer: This product is not legal for sale or use on pollution-controlled vehicles operated on public roads and is intended for off-road, race, or closed-course competition use only. You are responsible for compliance with all applicable emissions laws; use on public roads may violate the Federal Clean Air Act (42 U.S.C. § 7522) and similar state laws. Please check your local laws before purchase and installation.

Ships from our Vancouver shop — KORE SPEED is proudly Canadian-owned, with no surprise cross-border duties for Canadian buyers. Questions on fitment? Email support@korespeed.com.