Milltek Large-Bore Downpipe - BMW F80 M3 / F82 M4 - SSXBM1144

Milltek Resonated Cat Back Large-Bore Downpipe for BMW F80 M3 and F82 M4 (S55 engine). This resonated secondary catalyst delete is engineered for direct fitment to Milltek cat-back exhaust systems, combining increased flow capacity with refined sound character. The larger bore diameter reduces backpressure and improves scavenging efficiency compared to OEM units.

Fabricated from T304L stainless steel with mandrel-bent construction, this downpipe features a high-flow catalyst bypass design. Installation requires Stage 2 ECU remap for optimal tuning. Uses OEM hangers and mounting points—no modification required. Compatible with all Milltek cat-back systems for this platform.

• T304L stainless steel construction
• Mandrel-bent, seamless bore
• Resonated design for refined exhaust note
• Secondary catalyst delete configuration
• Direct OEM+ fitment to Milltek cat-back exhausts
• Requires Stage 2 ECU remap
• S55 engine compatible

Milltek downpipes are developed and tested to deliver measurable power gains without compromising drivability or longevity.

Fits Milltek Cat-Back.

Designed and manufactured in the UK with 40+ years of performance exhaust heritage. Tested at the Nurburgring.

Specifications

• Pipe diameter: 76.2mm (3.00")
• Off-road / competition use only. Not legal for use on public roads in the US.

Fitment

• BMW > 3 Series > F80 M3 & M3 Competition Saloon (Non OPF/GPF Models Only) > 2014 to 2018
• BMW > 4 Series > F82/83 M4 Coupe/Convertible & M4 Competition Coupe > 2014 to 2018

• Free US shipping on orders over $250.
• Free pickup at our Dallas shop, usually ready within 24 hours.
• Unused parts can be returned within 30 days. Tunes, opened electronics, merch and installed parts are final sale.
• Want it installed? Book the install at thegbmotors.com.

Full details are on our shipping and returns page.