Stone Exhaust Catless Performance Downpipe - (M140i, M240i, 340i, 440i, 540i, 740i, X3 M40i & X4 M40i)

In order to get even better efficiency for the section of exhaust turbine, as well as to prevent multiple welding positions in the downpipe section, which generates ash in the pipe while welding, causing bad exhaust efficiency, and then generates vaper lock and thus inability to exhaust, Stone Exhaust uses a variety of smart ideas in downpipe design. The company employs flow velocity measurement software in 3D and the technique of one-piece bend pipes, along with mechanical arms which accurately welds without generating ash in the pipe wall in order to further exhaust efficiency of Catless Downpipe. It is a perfect and effective product which has surpassed all similar products in the market.

• Catless downpipe for M140i, M240i, 340i, 540i, 740i, X4 M40i xDrive, X5 40i xDrive & X6 40i xDrive with B58 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 BMW B58 M140i, M240i, 340i, 440i, 540i, 740i. 

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.

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.

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.

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.

B58 Engine

BMW 1 Series

• F20 LCI/F21LCI M140i/M140i xDrive (2015+)

BMW 2 Series

• F22 M240i/M240i xDrive (2015+)
• F22 LCI M240i/M240i xDrive (2016+)
• F23 M240i/M240i xDrive (2015+)
• F23 LCI M240i/M240i xDrive (2016+)

BMW 3 Series

• F30 LCI/F31 LCI 340i/340i xDrive (2014+)

BMW 4 Series

• F32 440i/440i xDrive (2015+)
• F32 LCI 440i/440i xDrive (2016+)
• F33 440i/440i xDrive (2015+)
• F33 LCI 440i/440i xDrive (2016+)
• F36 440i/440i xDrive (2015+)
• F36 LCI 440i/440i xDrive (2016+)

BMW 5 Series

• G30 540i/540i xDrive (2015+)
• G31 540i xDrive (2016+)

BMW 7 Series

• G11 740i (2014+)
• G12 740i (2014+)/740i xDrive (2015+)
• G12 740Li (2014+)/740LI xDrive (2015+)

BMW X Series

• G02 X4/X3 M40i xDrive (2017+)
• G05 X5 40i xDrive (2017+)
• G06 X6 40i xDrive (2018+)

BMW Z Series

• G29 Z4 M40i (2019+)

A214P

Manufactured By

Stone Exhausts

Warranty

Stone Exhaust 2 Year Warranty