Meet the latest patented technology that adheres to the world's increasingly stringent environmental regulations, at the same time enhances performance to another level. In comparison to commercially available linear frustums, the "eddy catalytic technology" adopts an arc-packaging method. The turbine emissions process produces a vortex effect which purifies the exhaust gases while maintaining an equal amount of back pressure. When compared to a variety of conventional straight downpipes, the patented eddy catalytic technology can effectively increase horsepower and torque. In the lower rpm you will be immerse with vast amount of torque until you reach higher rpm where the vortex effect really comes to life and opens up the Catalytic, resulting in a performance similar to a 100 CELL Catalytic. However in the lower rpm, the catalytic will produce efficient and clean emission similar to a 400CEL Catalytic and produce no Check Engine Lights, completely error free.

• Patented O2 sensor technology design provides real-time data performance by accurately sensing every rotating displacement.
• No more delayed in power delivery
• Using one of the rare noble metal to help efficiently filter out exhaust gas.
• Computer simulation to obtain the best diameter.
• Special 3D design to achieve 100% OEM fitment, no modification required.
• SUS304 Premium Grade Stainless steel.
• Dual Cross-Welding Technology providing substantial increase durability. at Turbo Flange.
• UK MOT friendly and Euro 6 Compliant
• 76.2mm in Diameter

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 analyse factors such as pipe diameter, route and degrees of the bending angles of the N55 downpipe.

During R&D, Stone Exhaust utilises 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 utilising 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 defence industries.

With the state-of-the-art bending machine, Stone Exhaust has achieved the world leading 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 utilising this technology. With the combination of the CNC Bending machine, Reverse Engineering and 3D Design Scanning, Stone exhaust has created an integrally moulded exhaust pipe with an accuracy error of less 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 utilising 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 industry leading 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.

 
Art of Welding

You may also be interested in the Stone Exhaust M135i & M235i Cat-Back Valvetronic System to compliment the Eddy Catalytic Downpipe.

Power 

+ 24.4PS at 5734rpm

Torque

+ 16.6 ft. lb.s at 2921rpm

N55 Engine

BMW 1 Series 

• F20 M135i /M135i xDrive (2011-2015)
• F20 LCI M135i /M135i xDrive (2015-2018)
• F21 M135i (2011+) /M135i xDrive (2012-2015)
• F21 LCI M135i /M135i xDrive (2014-2016)

BMW 2 Series 

• F22 M235i (2012-2016)
• F22 M235i xDrive (2013-2016)
• F23 M235i/M235i xDrive (2014-2016)

BMW 3 Series

• F30/F31 330e/335i/ 335i xDrive (2011-2015)

BMW 4 Series

• F32 F33 F36 435i/435i xDrive (2012-2016)

BMW X Series

To ensure the part(s) you have ordered fits your vehicle, we run a compatibility check prior to dispatch. We can do this either using your registration number(UK) or the last 7 digits of your VIN. Simply enter your car details prior to checkout. 

A201E (PWG)

A202E (EWG)

Manufactured by

Stone Exhaust

Warranty

Stone Exhaust 2 Year Warranty