We are proud to introduce you to the state of the art Stone Exhaust OEM Integrated Valve Catback Exhaust System, to enhance the performance and sound of your BMW F20 3 Doors 120i, F21 3 Doors 120i, F22 Coupe 220i & F23 Convertible 220i with the B48 engine.

Stone Exhaust has been developing world's best exhaust system since 1998, starting with 3D scanning and reverse engineering the OEM system, this allows the Stone engineers to design a 100% OEM fitment exhaust with precision. With our in-house dyno, your BMW exhaust system is proven to produce more power with the enhanced Stone signature exhaust sound.

The OEM Integred Valves(s) option allows your exhuast system to operate as standard, where the onboard computer (ECU) will control the opening and closing of the valves automatically.

You can also add on Stone Cat-Back Valvetronic System Package (SKU: 1EV-S)

• STONE Valvetronic BMW B48 F21 LCI 125i Exhaust System.
• OEM Integration
• One Piece Design
• Mechanical Welding with Precision
• In House Research and Development
• 3D Scanning & Reverse Engineering
• Dyno Developed In House

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 Exhaust System found on the BMW.

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.

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.

AP525A (Require M235i bumper)  

Manufactured By

Stone Exhausts

Warranty

Stone Exhaust 2 Year Warranty  

Dimension 

110cm x 33cm x 60cm   

Weight

19.19 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.