{"product_id":"mad-bmw-s58-3-5-fatboy-x3m-x4m-f97-f98-downpipes","title":"MAD BMW S58 3.5'' FATBOY X3M \u0026 X4M F97 F98 Downpipes","description":"\u003cdiv class=\"l4lQedPGf8KN1w\" role=\"button\"\u003e\n\u003cdiv class=\"_4MrlvXRZe6dnu\" data-testid=\"comment-container\"\u003e\n\u003cdiv class=\"R1RfC8jJFTMJlv Xfg5GTUiZ1tTRp\"\u003e\n\u003cdiv class=\"kMMW7ykMIXwcjQ Ijf59q3IL0JsER\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"uilHrMFcZTKnuh\"\u003e\n\u003cdiv class=\"ak-renderer-wrapper is-full-width css-1jke4yk\"\u003e\n\u003cdiv class=\"css-1x3r43s\" role=\"none\"\u003e\n\u003cdiv class=\"ak-renderer-document\"\u003e\n\u003cp data-renderer-start-pos=\"73\"\u003eTake your BMW X3M or X4M to the next level with the\u003cspan\u003e \u003c\/span\u003e\u003cstrong data-renderer-mark=\"true\"\u003eMAD 3.5\" FatBoy Catless Downpipes\u003c\/strong\u003e. Designed for enthusiasts who demand maximum performance, our latest FatBoy design features a massive\u003cspan\u003e \u003c\/span\u003e\u003cstrong data-renderer-mark=\"true\"\u003e3.5-inch diameter\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003efor significantly improved exhaust flow over traditional downpipes.\u003c\/p\u003e\n\u003cp data-renderer-start-pos=\"73\"\u003eETA: Sept 2026\u003c\/p\u003e\n\u003cp data-renderer-start-pos=\"348\"\u003eEngineered specifically for the S58 platform, the MAD FatBoy Downpipes reduce exhaust backpressure, allowing the turbochargers to spool faster, improve throttle response, and unlock substantial horsepower and torque gains. Combined with an aggressive exhaust note and increased turbo sound, this is one of the most impactful upgrades you can make to your X3M or X4M.\u003c\/p\u003e\n\u003ch2 data-renderer-start-pos=\"716\" tabindex=\"-1\"\u003ePerformance Benefits\u003c\/h2\u003e\n\u003cp data-renderer-start-pos=\"738\"\u003eThe factory catalytic converters create a major restriction in the exhaust system. The MAD 3.5\" FatBoy Catless Downpipes eliminate this bottleneck, providing:\u003c\/p\u003e\n\u003cul class=\"ak-ul\" data-indent-level=\"1\"\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"900\"\u003eUp to\u003cspan\u003e \u003c\/span\u003e\u003cstrong data-renderer-mark=\"true\"\u003e30+ WHP\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eon stock turbochargers\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"940\"\u003eEven greater gains with upgraded turbochargers\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"990\"\u003eFaster turbo spool\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1012\"\u003eSharper throttle response\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1041\"\u003eReduced exhaust backpressure\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1073\"\u003eIncreased horsepower and torque\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1108\"\u003eLower exhaust temperatures\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1138\"\u003eImproved overall driving experience\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-renderer-start-pos=\"1177\" tabindex=\"-1\"\u003eWhy the FatBoy Design?\u003c\/h2\u003e\n\u003cp data-renderer-start-pos=\"1201\"\u003eUnlike conventional downpipes, the MAD\u003cspan\u003e \u003c\/span\u003e\u003cstrong data-renderer-mark=\"true\"\u003e3.5\" FatBoy\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003edesign maximizes exhaust volume immediately after the turbocharger, allowing exhaust gases to expand more efficiently for improved flow and performance.\u003c\/p\u003e\n\u003cp data-renderer-start-pos=\"1406\"\u003eThe result is:\u003c\/p\u003e\n\u003cul class=\"ak-ul\" data-indent-level=\"1\"\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1424\"\u003eMaximum exhaust flow\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1448\"\u003eImproved turbo efficiency\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1477\"\u003eIncreased horsepower potential\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1511\"\u003eMore aggressive exhaust tone\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1543\"\u003eLouder turbo whistle\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-renderer-start-pos=\"1567\" tabindex=\"-1\"\u003ePremium Construction\u003c\/h2\u003e\n\u003cp data-renderer-start-pos=\"1589\"\u003eEvery MAD FatBoy Downpipe is built to perform under the most demanding conditions.\u003c\/p\u003e\n\u003cp data-renderer-start-pos=\"1673\"\u003eFeatures include:\u003c\/p\u003e\n\u003cul class=\"ak-ul\" data-indent-level=\"1\"\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1694\"\u003eMassive\u003cspan\u003e \u003c\/span\u003e\u003cstrong data-renderer-mark=\"true\"\u003e3.5-inch FatBoy design\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1728\"\u003eHeavy-duty 304 stainless steel construction\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1775\"\u003ePrecision mandrel bends\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1802\"\u003eTIG welded and hand-finished\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1834\"\u003eSmooth internal transitions for unrestricted flow\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1887\"\u003eIntegrated flex sections to reduce stress on the exhaust system\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1954\"\u003ePrecision CNC-machined flanges\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"1988\"\u003eDirect bolt-on installation\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-renderer-start-pos=\"2019\"\u003eDesigned for both\u003cspan\u003e \u003c\/span\u003e\u003cstrong data-renderer-mark=\"true\"\u003eleft-hand drive (LHD)\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eand\u003cspan\u003e \u003c\/span\u003e\u003cstrong data-renderer-mark=\"true\"\u003eright-hand drive (RHD)\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003evehicles.\u003c\/p\u003e\n\u003ch2 data-renderer-start-pos=\"2097\" tabindex=\"-1\"\u003eBuilt for Performance\u003c\/h2\u003e\n\u003cp data-renderer-start-pos=\"2120\"\u003eWhether your vehicle is completely stock or running upgraded turbochargers, the MAD 3.5\" FatBoy Downpipes are designed to maximize performance while maintaining OEM-quality fitment.\u003c\/p\u003e\n\u003cp data-renderer-start-pos=\"2303\"\u003eCompatible with both factory and most aftermarket exhaust systems, they deliver an aggressive exhaust note without unnecessary turbulence or restriction.\u003c\/p\u003e\n\u003ch2 data-renderer-start-pos=\"2458\" tabindex=\"-1\"\u003eFeatures\u003c\/h2\u003e\n\u003cul class=\"ak-ul\" data-indent-level=\"1\"\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2470\"\u003eNEW\u003cspan\u003e \u003c\/span\u003e\u003cstrong data-renderer-mark=\"true\"\u003e3.5\" FatBoy design\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2496\"\u003eCatless construction\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2520\"\u003eMaximum exhaust flow\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2544\"\u003eFaster turbo spool\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2566\"\u003eSharper throttle response\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2595\"\u003eUp to\u003cspan\u003e \u003c\/span\u003e\u003cstrong data-renderer-mark=\"true\"\u003e30+ WHP\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eon stock turbos\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2628\"\u003eEven greater gains on upgraded turbos\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2669\"\u003eMore aggressive exhaust tone\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2701\"\u003eIncreased turbo whistle\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2728\"\u003eHeavy-duty 304 stainless steel construction\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2775\"\u003ePrecision TIG welded\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2799\"\u003eIntegrated flex sections\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2827\"\u003eSpot-on fitment\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2846\"\u003eCompatible with LHD and RHD vehicles\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2886\"\u003eWorks with factory and aftermarket exhaust systems\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"2940\"\u003eLifetime Warranty against manufacturing defects and fitment\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"3003\"\u003eShips in 1–2 business days\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-renderer-start-pos=\"3033\" tabindex=\"-1\"\u003eInstallation Notes\u003c\/h2\u003e\n\u003cp data-renderer-start-pos=\"3053\"\u003e\u003cstrong data-renderer-mark=\"true\"\u003eDownpipe gaskets are not included.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-renderer-start-pos=\"3089\"\u003eRequired for installation:\u003c\/p\u003e\n\u003cul class=\"ak-ul\" data-indent-level=\"1\"\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"3119\"\u003eBMW Gasket\u003cspan\u003e \u003c\/span\u003e\u003cstrong data-renderer-mark=\"true\"\u003ePart #18308053348\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e(Quantity: 2)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-renderer-start-pos=\"3165\" tabindex=\"-1\"\u003eFitment\u003c\/h2\u003e\n\u003cul class=\"ak-ul\" data-indent-level=\"1\"\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"3176\"\u003e\u003cstrong data-renderer-mark=\"true\"\u003e2019+ BMW X3M (F97)\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"3199\"\u003e\u003cstrong data-renderer-mark=\"true\"\u003e2019+ BMW X4M (F98)\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-renderer-start-pos=\"3222\" tabindex=\"-1\"\u003eSKU\u003c\/h2\u003e\n\u003cp data-renderer-start-pos=\"3227\"\u003e\u003cstrong data-renderer-mark=\"true\"\u003eMAD-041\u003c\/strong\u003e\u003c\/p\u003e\n\u003chr role=\"presentation\"\u003e\n\u003ch2 data-renderer-start-pos=\"3237\" tabindex=\"-1\"\u003eEmissions Disclaimer\u003c\/h2\u003e\n\u003cp data-renderer-start-pos=\"3259\"\u003eThis product is\u003cspan\u003e \u003c\/span\u003e\u003cstrong data-renderer-mark=\"true\"\u003enot legal for sale or use on pollution-controlled vehicles operated on public roads, highways, or streets.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eIt is intended for\u003cspan\u003e \u003c\/span\u003e\u003cstrong data-renderer-mark=\"true\"\u003eoff-road, race, or closed-course competition use only\u003c\/strong\u003e, where such modifications are permitted.\u003c\/p\u003e\n\u003cp data-renderer-start-pos=\"3497\"\u003eBy purchasing this product, you acknowledge and agree that:\u003c\/p\u003e\n\u003cul class=\"ak-ul\" data-indent-level=\"1\"\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"3560\"\u003eYou are responsible for complying with all applicable federal, state, and local emissions laws and regulations.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"3675\"\u003eMAD and its affiliates disclaim any liability for improper or unlawful use of this product.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-renderer-start-pos=\"3770\"\u003eUse of this product on public roads may violate the\u003cspan\u003e \u003c\/span\u003e\u003cstrong data-renderer-mark=\"true\"\u003eFederal Clean Air Act (42 U.S.C. § 7522)\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eand similar state laws.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-renderer-start-pos=\"3890\"\u003ePlease verify your local emissions regulations before purchasing or installing this product.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"k0CzrlJuI35cY8\"\u003e\n\u003cdiv class=\"rHlYGFm93Wv4G0\"\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Automotive365","offers":[{"title":"Default Title","offer_id":45071790014672,"sku":null,"price":319.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0593\/8639\/6880\/files\/1CC66911-7B25-4180-BA89-471A48063F15.jpg?v=1784305869","url":"https:\/\/automo365.com\/products\/mad-bmw-s58-3-5-fatboy-x3m-x4m-f97-f98-downpipes","provider":"Automotive365","version":"1.0","type":"link"}