{"product_id":"stone-exhaust-bmw-b58-f20-f21-m140i-cat-back-valvetronic-exhaust-system","title":"Stone Exhaust BMW 1 Series M140i B58 Valved Cat-Back\/Catback Performance Exhaust System (F20\/F21) - Switchable Valvetronic Rear Section, OEM Valve Control, No Drone, OPF\/GPF Friendly, Back Box + Mid Pipe | AP526A","description":"\u003cdiv class=\"product__description rte\"\u003e\n  \n  \u003ch2\u003eSwitchable Sports System for BMW 1 Series M140i B58 F20 F21\u003c\/h2\u003e\n  \u003cp\u003eGive your B58-powered M140i the soundtrack it deserves. This Stone Exhaust switchable rear system delivers a deeper, crisper tone when the flap is open and calm refinement when it is shut, with no cabin boom at motorway speeds. Designed via full 3D scan of the factory layout, it bolts up cleanly, aligns perfectly and integrates with the original valve actuator for factory-style control.\u003c\/p\u003e\n  \n  \u003ch3\u003eWhat makes it a standout upgrade\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eFactory valve integration. Uses the original actuator and ECU logic for quiet and loud modes, just as the car intended.\u003c\/li\u003e\n    \u003cli\u003eOptional remote control. Add the Stone Valvetronic single valve kit for on-demand sound at the press of a button.\u003c\/li\u003e\n    \u003cli\u003eSmooth, one-piece layout that promotes flow and makes installation straightforward.\u003c\/li\u003e\n    \u003cli\u003ePlug and play OBDII controller available for enhanced control flexibility.\u003c\/li\u003e\n    \u003cli\u003eEngineered to eliminate drone so daily driving remains relaxed and conversation friendly.\u003c\/li\u003e\n    \u003cli\u003e3D scanned and reverse engineered for true OEM-style fitment on the F20 and F21 chassis.\u003c\/li\u003e\n    \u003cli\u003eIn-house dyno development for response, tone and drivability that suit both road and spirited use.\u003c\/li\u003e\n    \u003cli\u003e7-axis CNC mandrel bending maintains up to 98 percent roundness at tight radii, reducing turbulence.\u003c\/li\u003e\n    \u003cli\u003ePrecision mechanical welds with criss-cross and overlapping techniques for long-term durability under heat.\u003c\/li\u003e\n  \u003c\/ul\u003e\n  \n  \u003ch3\u003eSound and drivability\u003c\/h3\u003e\n  \u003cp\u003eFlap closed delivers an OEM-like hush for early starts and long journeys. Open it up and the turbocharged straight six comes alive with a rich, motorsport-inspired note and sharper character. No resonance, just a clean, purposeful voice that suits the B58 perfectly.\u003c\/p\u003e\n  \n  \u003ch3\u003eOPF and GPF compatibility\u003c\/h3\u003e\n  \u003cp\u003eRunning a particulate filter. An OPF solution is included free of charge to support fitment on OPF-equipped cars without warning lights, so no ECU coding is required.\u003c\/p\u003e\n  \n  \u003ch3\u003eFitment\u003c\/h3\u003e\n  \u003cp\u003eFor BMW 1 Series M140i with the B58 3.0 turbo engine:\u003c\/p\u003e\n  \u003cul\u003e\n    \u003cli\u003eF20 M140i 5-door\u003c\/li\u003e\n    \u003cli\u003eF21 M140i 3-door\u003c\/li\u003e\n  \u003c\/ul\u003e\n  \n  \u003ch3\u003eRecommended add-ons\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eStone Exhaust B58 Catless Performance Downpipe\u003c\/li\u003e\n    \u003cli\u003eStone Exhaust B58 Eddy Catalytic Performance Downpipe\u003c\/li\u003e\n    \u003cli\u003eStone Valvetronic System single valve remote kit\u003c\/li\u003e\n  \u003c\/ul\u003e\n  \u003cp\u003ePairing the system with a performance downpipe and the remote kit is a popular route to maximise flow, response and soundtrack.\u003c\/p\u003e\n  \n  \u003ch3\u003eReal-world results\u003c\/h3\u003e\n  \u003cp\u003eWe run this on our own cars and fit it for customers who want a premium M140i upgrade that sounds superb, lines up perfectly and stays civilised on longer trips. Feedback has been consistently positive on quality, valve operation and the absence of drone.\u003c\/p\u003e\n  \n  \u003ch3\u003eInstallation and support\u003c\/h3\u003e\n  \u003cp\u003eProfessional fitting available at MJ Modifications in Warwickshire. For a fitting quote or advice, email \u003ca href=\"mailto:info@mjmodifications.co.uk\"\u003einfo@mjmodifications.co.uk\u003c\/a\u003e.\u003c\/p\u003e\n  \n  \u003ch3\u003eWarranty\u003c\/h3\u003e\n  \u003cp\u003eStone Exhaust 2 Year Warranty.\u003c\/p\u003e\n  \n  \u003ch3\u003eManufacturer\u003c\/h3\u003e\n  \u003cp\u003eStone Exhaust\u003c\/p\u003e\n  \n  \u003ch3\u003ePart number\u003c\/h3\u003e\n  \u003cp\u003e\u003cstrong\u003eAP526A\u003c\/strong\u003e\u003c\/p\u003e\n  \n  \u003ch3\u003eSearch-friendly terms\u003c\/h3\u003e\n  \u003cp\u003eM140i sports exhaust upgrade, B58 1 Series switchable flap system, BMW M140i performance rear section, F20 F21 M140i valve controlled system, turbo straight six exhaust sound, OPF GPF friendly M140i exhaust, M140i back box and mid section upgrade, M140i quiet to loud exhaust, plug and play valve exhaust M140i, BMW 1 Series B58 sports system, UK M140i exhaust specialists, M140i performance pipework, M140i flap exhaust no drone, BMW M140i F20 F21 exhaust AP526A.\u003c\/p\u003e\n  \n\u003c\/div\u003e","brand":"Stone Exhaust","offers":[{"title":"OEM Integrated Valve(s) \/ Flat Cut Gloss Carbon Fiber (82mm)","offer_id":55977884156290,"sku":null,"price":3068.88,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0871\/5445\/8937\/files\/8200CG_FlatCutGlossCarbonFiber82mmExhuastTailpipes_1024x1024_2_540x_c0c11351-d8f8-475a-aff4-774d99ca27a0.webp?v=1763377161","url":"https:\/\/mjmodifications.co.uk\/products\/stone-exhaust-bmw-b58-f20-f21-m140i-cat-back-valvetronic-exhaust-system","provider":"MJ Modifications","version":"1.0","type":"link"}