Meet the latest 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 "arc fluid twist-flow 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 horsepower tests and straight downpipes, our patented arc fluid twist-flow catalytic technology can effectively increase horsepower and torque.

• Patented O2 sensor technology design provides real-time data performance by accurately sensing every rotating displacement. No more delayed or error code problem.
• Using one of the rare noble metal to help efficiently filter out exhaust gas.
• Computer simulation of the best diameter.
• A special 3D design able to achieve a perfectly matching model with the original pipe. the same installation applies, no need to modify.
• SUS304 Stainless steel.
• Dual Cross-Welding Technology providing substantial increase durability.
• UK MOT friendly and Euro 6 Compliant  

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 1.5T Exhaust System found on the Ford MK4 Focus 1.5T. 

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. 

1.5T Engine

Ford MK4 Focus 1.5T (2018+)

Manufactured by

Stone Exhaust

Eddy Catalytic DP V.S Stock

Ford MK4 Focus 1.5T With Stone Exhaust Eddy DP + Valvetronic Cat-back Sound