BMW 650i N63 / N63TU 3" Catless Downpipes

Take your N63/N63TU 4.4L twin-turbo V8 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 exhaust back-pressure so the turbos spool faster and power and torque climb across the rev range — while unlocking a shocking exhaust note from the turbo V8.

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 over Stage 2 — for a total of 460 awhp / 525 awtq.

Construction

• Full 304 stainless, 3" construction following the OEM flow path for factory-precise fitment.
• Flex section plus upper and lower brackets (engine block and transmission housing) to relieve turbo stress from engine movement.
• Two O2 sensor bungs per downpipe to 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 precisely calibrated O2 sensor spacers in the post-catalyst 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.