{"product_id":"er-comp-catless-dp-n55-x5x6","title":"Evolution Racewerks Competition Series 4\" Catless Downpipe — N55 (X5 \/ X6)","description":"\u003cp\u003e\u003cstrong\u003eEvolution Racewerks Competition Series 4\" catless downpipe for the single-turbo N55 in the X5 35i and X6 35i (F15\/F16).\u003c\/strong\u003e Replaces the factory downpipe and catalytic converter — the post-turbo restriction that caps a tuned N55 — with a mandrel-bent 4\" stainless pipe.\u003c\/p\u003e\n\u003ch3\u003eWhy a downpipe on the N55\u003c\/h3\u003e\n\u003cp\u003eThe factory downpipe is built around the cat for emissions, and at Stage 2 boost it becomes the limiting factor on spool and top-end. Opening it to a full 4\" lets an Esse Werks calibration use the turbo's real airflow ceiling.\u003c\/p\u003e\n\u003ch3\u003eWhat Evolution Racewerks builds in\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eMandrel-bent 4\" piping (expanded from the factory 3.5\" turbo outlet), 100% T304 stainless\u003c\/li\u003e\n\u003cli\u003eCNC-machined billet 304 stainless V-band turbo flange (factory 3.5\" V-band)\u003c\/li\u003e\n\u003cli\u003e100% stainless-steel flex section for driveline movement\u003c\/li\u003e\n\u003cli\u003e100% TIG-welded; made in the USA at Evolution Racewerks' California facility\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFinishes\u003c\/h3\u003e\n\u003cp\u003eBrush, Polish, or our signature \u003cstrong\u003eSwainTech White Lightning\u003c\/strong\u003e ceramic coating — choose above.\u003c\/p\u003e\n\u003ch3\u003eSwainTech White Lightning — our signature coating\u003c\/h3\u003e\n\u003cp\u003eWhen we coat a part, we use one coating: SwainTech White Lightning — a true ceramic thermal barrier applied about 0.015\" thick (versus roughly 0.002\" for paint-style \"ceramic\" finishes) and sprayed molten so it bonds to the metal instead of sitting on top. It cuts radiant heat off the exhaust by roughly 35–55%, dropping underhood and intake temperatures, and keeps heat inside the pipe where it sustains exhaust velocity and scavenging. And it's white — a deliberate signature in a market that otherwise all looks the same in black. Select it above.\u003c\/p\u003e\n\u003ch3\u003eCalifornia restriction\u003c\/h3\u003e\n\u003cp\u003eRace\/competition part. Not for sale, installation, or use on pollution-controlled vehicles in California — 49-state product; Vehicle Compliance Waiver signed at order intake. International orders ship without restriction.\u003c\/p\u003e\n\u003ch3\u003eFitment\u003c\/h3\u003e\n\u003cp\u003eBMW N55 — X5 35i and X6 35i (F15\/F16). Confirm your chassis in the selector.\u003c\/p\u003e\n\u003cp\u003eThis part is the downpipe-side core of every N55 Stage 2 build. The \u003ca href=\"\/products\/stage-2-kit-n55\"\u003eStage 2 Kit — N55\u003c\/a\u003e packages the matched parts + calibration for 8% under à la carte.\u003c\/p\u003e","brand":"Evolution Racewerks","offers":[{"title":"Brush Finish","offer_id":43280703422525,"sku":"BM-EXH-N55-X5X6","price":765.0,"currency_code":"USD","in_stock":true},{"title":"Polish Finish","offer_id":43280703455293,"sku":"BM-EXH-N55-X5X6-P","price":815.0,"currency_code":"USD","in_stock":true},{"title":"SwainTech White Lightning","offer_id":43280703488061,"sku":"BM-EXH-N55-X5X6-CER","price":1015.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0658\/2553\/8109\/files\/ER__competition-series-4-catless-downpipe-for-the-x5-x6-series-n55-6-cylinder-engine__01.webp?v=1781743118","url":"https:\/\/essewerks.com\/products\/er-comp-catless-dp-n55-x5x6","provider":"Esse Werks","version":"1.0","type":"link"}