Stone Exhaust BMW B58 F20 F21 M140i OEM Integrated Valved Cat-Back Exhaust System
Transform your BMW M140i with the Stone Exhaust OEM Integrated Valved Cat-Back Exhaust System for the B58 engine. This premium BMW M140i catback exhaust delivers a deeper, sharper tone with valves-open excitement and quiet cruising when closed. It is the perfect performance exhaust upgrade for the F20 and F21 M140i, engineered for OEM fitment, improved flow and zero drone on the motorway.
Developed using 3D scanning and reverse engineering of the factory system, Stone Exhaust has created a precise, bolt-on solution that integrates seamlessly with your OEM valve control. Backed by in-house dyno development and exceptional build quality, this M140i valved exhaust is designed to enhance sound and drivability while retaining everyday comfort.
Why choose this BMW M140i B58 catback exhaust
- OEM integrated valves. Uses the factory ECU to open and close the exhaust valves just like stock.
- Optional Stone Valvetronic System single valve kit. Add remote control of the valves for ultimate flexibility.
- One-piece design. Clean flow path and simplified installation for your BMW M140i F20 F21.
- Plug and play OBDII controller available.
- Eliminates drone found on the standard exhaust system. Enjoy daily driving without cabin resonance.
- 3D scanning and reverse engineering for 100 percent OEM fitment and alignment.
- Dyno developed in-house for proven performance and the Stone signature exhaust sound.
- 7-axis CNC bending for exceptional roundness and consistency.
- Precision mechanical welding, criss-cross and overlapping techniques for strength and durability.
Sound and drivability
With valves closed you get refined OEM-like comfort. With valves open you unlock an aggressive, motorsport-inspired tone that lets the B58 sing. No drone. Just a precise, responsive exhaust note that suits road and spirited driving.
OPF compatibility
Running an OPF equipped M140i. Stone offers an OPF delete solution that is included free of charge. This allows installation on OPF vehicles without triggering error codes, so ECU coding is not required.
Engineering highlights
- R&D and 3D scanning of OEM BMW M140i exhaust geometry for optimal pipe routing and diameters.
- 7-axis CNC bending maintains up to 98 percent roundness even at tight 180 degree bends, reducing turbulence.
- Advanced welding methods for high-temperature endurance and long-term reliability.
Fitment
BMW 1 Series M140i with B58 engine
- F20 M140i 5-door
- F21 M140i 3-door
Recommended add-ons
- Stone Exhaust BMW B58 Catless Performance Downpipe
- Stone Exhaust BMW B58 Eddy Catalytic Performance Downpipe
- Stone Valvetronic System single valve remote kit
These upgrades are frequently purchased together with this cat-back to maximise performance and sound.
Real-world results with Nforcd
We have run this system on our own cars and fitted it for customers who want a premium BMW M140i exhaust that sounds fantastic, fits perfectly and remains comfortable day to day. Feedback has been consistently positive about the quality, valve control and drone-free cruising.
Fitting and support
Professional fitting available at Nforcd in Warwickshire. For a fitting quote or advice, email Sales@nforcd.com.
Warranty
Stone Exhaust 2 Year Warranty.
Manufacturer
Stone Exhaust
Part number
AP526A
Search-friendly terms
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