Stone Exhaust BMW N26 F30 F32 OEM Integrated Valved Cat-Back Exhaust System for 328i and 428i
Transform your BMW 328i or 428i with the Stone Exhaust OEM integrated valved cat-back exhaust system built specifically for the N26 engine. Designed for the BMW F30 328i saloon 2011+, F32 428i coupé 2013+ and F33 428i convertible 2013+, this premium cat-back delivers OEM-level fitment, a deeper Stone signature sound and proven performance gains. Developed using 3D scanning and reverse engineering of the factory system, the Stone Exhaust cat-back fits like OEM and elevates your driving experience every time you press the throttle.
The OEM integrated valve allows seamless control by your car’s ECU for refined everyday driving when closed and an aggressive tone when open. Prefer full control? Add the optional Stone Valvetronic System single valve with plug and play OBDII controller and switch between quiet and loud on demand.
Why choose Stone Exhaust for your BMW 328i and 428i N26
- OEM integrated valved cat-back exhaust for N26 F30 328i and F32 F33 428i
- Genuine 100% OEM fitment accuracy thanks to 3D scanning and reverse engineering
- Proven on Stone’s in-house dyno to deliver more power with a crisper throttle response
- Stone signature exhaust note with refined volume control via OEM valve
- Eliminates drone commonly found on standard systems for comfortable cruising
- Optional Stone Valvetronic System single valve with remote control and OBDII plug and play
- One piece design for strength and optimal flow
- Mechanical welding with precision for durability and reliability
- In-house research and development for consistent quality
Compatibility - N26 engine
- BMW 3 Series F30 328i 2011+
- BMW 4 Series F32 428i 2013+
- BMW 4 Series F33 428i 2013+
Available variants and part numbers
- AP501N26 - Single exit left with twin tailpipes
- AP512N26 - Dual exit with single tailpipe
- AP512QN26 - Dual exit with quad tailpipes
Engineering that sets Stone Exhaust apart
Stone engineers deploy advanced 3D scanning of OEM components to map pipe diameter, routing and bend angles, then iterate using flow, thermal and pressure simulations until optimal performance is achieved. The result is an OEM-plus solution that boosts power and sound while maintaining everyday usability.
Using a 7 axis CNC bending machine, Stone achieves up to 98 percent roundness with minimal outer bore wear at tight bends, reducing turbulence and preventing weld fracture. Crisscross and overlapping welding techniques increase penetration and width for robust joints that withstand extreme temperatures. Precision direct spot welding by mechanical arms delivers consistent strength and a finish that looks as good as it performs.
Real-world results and customer feedback
We have fitted and run Stone Exhaust systems on our own builds and for many of our customers. Feedback is consistently positive on the fitment quality, the zero-drone cruising and the perfect balance of refined OEM valve-closed manners with a properly sporty tone when open. It is the ideal upgrade for a daily driven BMW 328i or 428i that still wants a weekend soundtrack.
Fitting and support
Professional fitting available at Nforcd in Warwickshire. Request a fitting quote or advice via Sales@nforcd.com.
Warranty
Stone Exhaust 2 year warranty.
Manufactured by
Stone Exhaust
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