{"product_id":"milltek-80mm-opf-back-exhaust-for-bmw-g8x-m3-m4-carbon-fibre-tips-ssxbm1321","title":"Milltek 80mm OPF Back Exhaust for BMW G8X M3 M4, Carbon Fibre Tips","description":"\u003cp\u003eMilltek OPF\/GPF-back exhaust system for BMW G8X M3 and M4 (2021+). Direct factory fitment with centre resonator bypass and CNC-formed JET-115 carbon fibre trims. OE gasoline particulate filter remains in place; system mounts downstream.\u003c\/p\u003e\n\u003cp\u003eT304L stainless steel, mandrel-bent construction throughout. Hand-finished welds. System engineered to restore acoustic character lost through OE particulate filtration while maintaining full emissions compliance. Centre resonator bypass refines mid-range tone; full-throttle note tuned for the S58 engine architecture.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eT304L stainless steel, mandrel-bent pipes\u003c\/li\u003e\n\u003cli\u003eOE hangers and mounting points - no modification required\u003c\/li\u003e\n\u003cli\u003eCentre resonator bypass system included\u003c\/li\u003e\n\u003cli\u003eCNC carbon fibre tailpipe trims (JET-115 spec)\u003c\/li\u003e\n\u003cli\u003eOE particulate filter compatibility (cutting of OE silencer required)\u003c\/li\u003e\n\u003cli\u003eDecibel-tested for full-load character\u003c\/li\u003e\n\u003cli\u003eEC type-approved construction\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eMilltek develops OPF-back systems to balance OE+ acoustic engineering with emissions regulations. Where OE systems sacrifice tone for particulate capture, this system reclaims the B58\/S58 soundtrack without sacrificing filter function.\u003c\/p\u003e\n\u003cp\u003eFits OE system.\u003c\/p\u003e\n\u003cp\u003eDesigned and manufactured in the UK with 40+ years of performance exhaust heritage. Tested at the Nurburgring.\u003c\/p\u003e\n\u003ch3\u003eVehicle fitment\u003c\/h3\u003e\n\u003cul class=\"fitment-list\"\u003e\n\u003cli\u003e2021-2026 BMW M3 Competition\u003c\/li\u003e\n\u003cli\u003e2021-2026 BMW M4 Competition\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Milltek","offers":[{"title":"Default Title","offer_id":60150797893918,"sku":"MILSSXBM1321","price":4827.84,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0759\/7965\/3406\/files\/SSXBM1321_1.jpg?v=1791255535","url":"https:\/\/shop.signatureautohaus.com\/products\/milltek-80mm-opf-back-exhaust-for-bmw-g8x-m3-m4-carbon-fibre-tips-ssxbm1321","provider":"Signature Autohaus","version":"1.0","type":"link"}