{"product_id":"b58-cast-stainless-steel-high-flow-performance-downpipe-bmw-f-g-series-15-21","title":"B58 High-Flow Performance Downpipe – BMW F \u0026 G Series (15-21)","description":"\u003cp data-path-to-node=\"1\"\u003eThe \u003cb data-index-in-node=\"17\" data-path-to-node=\"1\"\u003eB58 High-Flow Performance Downpipe\u003c\/b\u003e is the single most effective bolt-on modification available to unlock the hidden performance potential of BMW’s highly acclaimed 3.0L turbocharged inline-six engine. The factory downpipe is engineered with a dense, restrictive catalytic converter designed primarily for stringent emissions regulations, which creates significant exhaust backpressure right at the turbocharger exit. This performance upgrade replaces that restriction with a smooth, oversized, CAD-designed casting that drastically reduces backpressure, lowers thermal stress on the turbocharger, and accelerates exhaust gas velocity.\u003c\/p\u003e\n\u003cp data-path-to-node=\"2\"\u003eManufactured from heavy-duty, aircraft-grade \u003cb data-index-in-node=\"45\" data-path-to-node=\"2\"\u003eT304 Stainless Steel\u003c\/b\u003e, this downpipe features precision TIG-welded construction and a smooth-walled internal diameter. Maximising exhaust flow, it allows the twin-scroll turbocharger to spool up significantly faster, virtually eliminating turbo lag and sharpening throttle response. In addition to substantial power gains, it transforms the acoustic profile of the B58, delivering a deep, aggressive, and crisp exhaust note under acceleration while remaining refined during normal cruising.\u003c\/p\u003e\n\u003cp data-path-to-node=\"3\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"3\"\u003eVehicle Compatibility:\u003c\/b\u003e\u003c\/p\u003e\n\u003cp data-path-to-node=\"3\"\u003eThis high-flow downpipe is precision-engineered to bolt directly onto B58-equipped (Gen 1) vehicles across both F and G-chassis generations:\u003c\/p\u003e\n\u003cul data-path-to-node=\"4\"\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"4,0,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"4,0,0\"\u003e1 Series (F20\/F21):\u003c\/b\u003e 2016–2019 M140i (3-door \u0026amp; 5-door Hatchback)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"4,1,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"4,1,0\"\u003e2 Series (F22\/F23):\u003c\/b\u003e 2016–2021 M240i (Coupe \u0026amp; Convertible)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"4,2,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"4,2,0\"\u003e3 Series (F30\/F31\/F34):\u003c\/b\u003e 2015–2019 340i (Sedan, Touring, \u0026amp; Gran Turismo)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"4,3,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"4,3,0\"\u003e4 Series (F32\/F33\/F36):\u003c\/b\u003e 2016–2020 440i (Coupe, Convertible, \u0026amp; Gran Coupe)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"4,4,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"4,4,0\"\u003e5 Series (G30\/G31):\u003c\/b\u003e 2017–2019 540i \/ 540iX\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"4,5,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"4,5,0\"\u003e7 Series (G11\/G12):\u003c\/b\u003e 2015–2019 740i \/ 740Li\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"4,6,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"4,6,0\"\u003eX Series (G01\/G02):\u003c\/b\u003e 2017–2019 X3 M40i \/ X4 M40i\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-path-to-node=\"5\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"5\"\u003eKey Features:\u003c\/b\u003e\u003c\/p\u003e\n\u003cul data-path-to-node=\"6\"\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"6,0,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"6,0,0\"\u003eMaximised Power \u0026amp; Torque:\u003c\/b\u003e Yields an estimated increase of 15–25 horsepower and 20–30 lb-ft of torque on a stock tune, and serves as a mandatory hardware requirement for Stage 2 ECU software calibrations.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"6,1,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"6,1,0\"\u003eOptimized Thermal Efficiency:\u003c\/b\u003e Substantially reduces EGTs (Exhaust Gas Temperatures) at the turbo manifold, protecting critical engine components during high-load or track conditions.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"6,2,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"6,2,0\"\u003ePremium T304 Construction:\u003c\/b\u003e Built with mandrel-bent stainless steel tubing and robust CNC-machined flanges to guarantee exceptional durability and zero warping under extreme heat.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"6,3,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"6,3,0\"\u003ePerfect OEM Placement:\u003c\/b\u003e Retains factory mounting brackets, oxygen (\u003cspan data-index-in-node=\"66\" data-math=\"O_2\" class=\"math-inline\"\u003e$O_2$\u003c\/span\u003e) sensor bungs, and heat-shield connection points for a direct, stress-free bolt-on installation.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"6,4,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"6,4,0\"\u003eFlex-Section Integration:\u003c\/b\u003e Features a heavy-duty inner-lined flexible bellow section to isolate engine movement, absorbing vibrations and preventing exhaust system cracking.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-path-to-node=\"8\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"8\"\u003eSpecifications:\u003c\/b\u003e\u003c\/p\u003e\n\u003cul data-path-to-node=\"9\"\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"9,0,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"9,0,0\"\u003eEngine Application:\u003c\/b\u003e BMW B58 3.0L Turbo Inline-6 (Gen 1)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"9,1,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"9,1,0\"\u003eChassis Compatibility:\u003c\/b\u003e F20 \/ F22 \/ F30 \/ F32 \/ G30 \/ G01\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"9,2,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"9,2,0\"\u003eMaterial:\u003c\/b\u003e T304 Stainless Steel (Mandrel-Bent)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"9,3,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"9,3,0\"\u003eTubing Diameter:\u003c\/b\u003e 4.0\" (102mm) tapered down to 3.15\" (80mm) to match factory exhaust routing\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"9,4,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"9,4,0\"\u003eO2 Sensor Bungs:\u003c\/b\u003e Dual Factory-Location Threaded Connections\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp data-path-to-node=\"9,5,0\"\u003e\u003cb data-index-in-node=\"0\" data-path-to-node=\"9,5,0\"\u003eCondition:\u003c\/b\u003e Brand New High-Performance Hardware Set\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"MYTY Auto Parts","offers":[{"title":"Default Title","offer_id":49567109120239,"sku":"MYTY023","price":5000.0,"currency_code":"ZAR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0769\/7183\/5631\/files\/B58-High-Flow-Stainless-Steel-Performance-Downpipe-BMW-140i-240i-340i.png?v=1779260578","url":"https:\/\/myty.co.za\/products\/b58-cast-stainless-steel-high-flow-performance-downpipe-bmw-f-g-series-15-21","provider":"MYTY Auto Parts","version":"1.0","type":"link"}