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 "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 horsepower tests and straight downpipes, our patented eddy 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.

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 B48D Exhaust System found on the BMW G20 G21. 

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.

Valvetronic System

The Stone Valvetronic System was independently researched and developed in house. The system forgoes the conventional design of complicated wiring and the rubber inside the valve which is prone to aging, to ensure longevity.

With the Valvetronic remote control providing three modes to choose from: ON / OFF / AUTO, this allows for instant switching between modes in accordance to driving conditions faced. So, let the STONE Valvetronic System adapt to your vehicle’s needs.

The Valvetronic remote control has 3 modes, ON / OFF / AUTO, which allows you to open and close the valve at a click of a button. The Auto mode allows customization of the opening and closing of the valve at a predefined RPM.

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.

B48D Engine

BMW Z Series

• G29 Z4 20/30i (2019+)

BMW 3 Series

• G20 G21 320i (2019+)
• G20 G21 330i/330i xDrive (2017+)

BMW 4 Series

• G22 420/430i(x)  (2020+)
• G23 420/430i(X)  (2020+)
• G26 420/430i(x)  (2020+)

A218E

Manufactured By

Stone Exhausts

Warranty

Stone Exhaust 2 Year Warranty

Emission Notice 

Various U.S. states and the U.S. federal government have individual laws regulating the use of aftermarket exhaust parts and system, especially when the stock system is modified, remove, or if you are replacing original catalysts. Please consult the appropriate law department 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 laws.