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Stone Exhaust BMW B48 F20 F22 F30 F32 F36 Catless Downpipes (Inc. 120i, 125i, 220i, 230i, 320i, 330i, 420i & 430i) | Stone Exhuast USA
Stone Exhaust BMW B48 F20 F22 F30 F32 F36 Catless Downpipes (Inc. 120i, 125i, 220i, 230i, 320i, 330i, 420i & 430i) | Stone Exhuast USA

Stone Exhaust BMW B46 G20 F22 F30 F34 F32 Catless Downpipe (Inc. 230i, 330i, 330i xDrive GT, 430i, 520i & 530i / Non OPF Model)

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Stone Exhaust employs state of the art 3D flow velocity measurement software and the technique of a one-piece mandrel bent pipe design. Using mechanical welding arms to accurately weld stops ash generating in the pipe wall which can cause vapor lock and poor exhaust efficiency. Stone Exhaust’s innovative manufacturing process of the catless downpipe prevents multiple welding positions and vapor lock whilst maximizing efficiency of the exhaust turbine.



  • Catless downpipe for 230i, 330i, 330i xDrive GT, 430i, 520i & 530i with B46 engine.
  • Unique Flex design to prevent breakage caused by extreme heat 
  • Crisscross welding to strengthen turbo flange
  • One Piece Design
  • Machine Welding
  • In House Research and Development
  • 3D Scanning & Reverse Engineering
  • 100% OEM Fitment


    R&D and 3D Scanning

    Stone Exhaust engineers use reverse engineering by 3D scanning OEM parts to understand their functionality and identify weaknesses. Data has been collected continuously in order to analyze factors such as pipe diameter, route and degrees of the bending angles of the B46 Exhaust Systems.

    During R&D, Stone Exhaust utilizes the 3D simulation software to stimulate the exhaust gas flow movement, thermal and pressure rise zone. Progressive improvements were continually made until the optimal performance was achieved.

    Stone Exhaust System 3D Scanning Reverse Engineering UK


    7 Axis CNC Bending Machine

    Stone Exhaust System are constructed utilizing a 7 axis CNC Bending Machine which is the ultimate machine for high levels of precision delivery, necessary for industries such as the aerospace and defense industries.

      With the state-of-the-art bending machine, Stone Exhaust has achieved the industry’s standard to an impressive 98% roundness, whilst maintaining the wear of the outer bore at only 25% at 180°. Airflow obstruction and welding fracture problems are prevented by utilizing this technology. With the combination of the CNC Bending machine, Reverse Engineering and 3D Design Scanning, Stone exhaust has created an integrally molded exhaust pipe with an accuracy error under 0.025mm.

       7 Axis CNC Bending Machine | Stone Exhaust USA


      Crisscross and Overlapping Welding Technique

      The flange between the turbo and the downpipes reaches extreme temperatures (800℃ to 1100℃) which creates stress on the connection point. By utilizing both welding techniques to increases the width and penetration of welds. This increases the endurance and tolerance of these connection points, leading to quality products with reliable performance.

      Stone Exhaust Art of Welding - Stone Exhaust USA


      Direct Spot Welding

      Our highly skilled engineers perform direct spot welding to increase product strength. This is undertaken by mechanical welding arms, proven to achieve greater precision and penetration in their welds compared to manual welding, resulting in an end product that is a work of art.

      Stone Exhaust Art of Welding - Stone Exhaust USA


      Compatibility - B46 Engine

        BMW 2 Series 

        • F22 230i/230i xDrive (2015-2017)
        • F22 LCI 230i (2017-2018)/ 230i xDrive (2016-2018)
        • F23 230i xDrive (2015-2017)
        • F23 LCI 230i xDrive (2016-2018)

        BMW 3 Series

        • F30 LCI 330i (2014-2018)
        • F31 LCI 330i xDrive (2015-2019)
        • F34 LCI 330i xDrive GT (2015-2019) 

        BMW 4 Series

        • F32 LCI 430i/430i xDrive (2016-2019)
        • F33 LCI 420i/430i/430i xDrive (2016-2019)
        • F36 LCI 420i/420i xDrive/430i (2016-2019)

        BMW 5 Series

        • G30 520i (2016-2018)
        • G30 530i/530i xDrive (2015-2018)

        BMW X Series

        • G01 X3 20i xDrive (2017-2018) / X3 30i xDrive (2016-2018)
        • G02 X4 20i xDrive (2017-2019) / X4 30i xDrive (2017-2019)





            Stone Exhaust 2 Year Warranty



            70cm x 20m x 18cm 


            2.21 kg 


            Emission Notice 

            Various U.S. states and the U.S. federal government have individual laws regulating the use of aftermarket exhaust parts and systems, especially as those parts and systems modify, remove, or replace original equipment catalysts. Please consult the appropriate laws in your area before installing any aftermarket part or system on your vehicle to ensure compliance with all applicable laws. The purchasers are entirely responsible for informing themselves of the applicable laws where the products are to be used and to comply with those law.