Stone Exhaust BMW N20 F30 F32 OEM Integrated Valved Catback Exhaust System for 328i and 428i
Upgrade your BMW 328i or 428i with the Stone Exhaust OEM Integrated Valved Catback Exhaust System and enjoy a deeper, sportier sound, OEM perfect fitment and proven performance. Designed specifically for the BMW N20 engine in the F30 3 Series and F32 F33 F36 4 Series, this valved cat back exhaust delivers everyday refinement with the excitement you expect when the valves open. If you are searching for BMW 328i exhaust, BMW 428i exhaust, BMW F30 catback, BMW F32 catback, N20 valved exhaust or quad exhaust for F30 and F32, this is the premium UK choice.
Why choose Stone Exhaust for your BMW 328i and 428i
- OEM integrated valve operation controlled by the factory ECU for seamless Comfort to Sport behaviour.
- Optional Stone Valvetronic System Single Valve upgrade available for remote valve control via plug and play OBDII controller.
- One piece design for strength, durability and consistent flow.
- 3D scanning and reverse engineering of the OEM system for 100 percent OEM fitment and precision alignment.
- Dyno developed in house by Stone Exhaust for real, repeatable gains with the signature Stone sound.
- 7 axis CNC bending for exceptional roundness and accuracy, reducing turbulence and improving gas flow.
- Mechanical welding with precision including crisscross and overlapping techniques for endurance at high temperatures.
- Direct spot welding by automated arms for superior penetration and consistency.
- Eliminates the drone found on the standard exhaust system for comfortable motorway cruising.
- In house research and development focused on flow, temperature and pressure optimisation.
How the OEM integrated valve works
The OEM Integrated Valve option uses your car’s ECU to automatically open and close the exhaust valve. This preserves factory drivability and keeps things quiet when you want, then releases a richer, more aggressive note when you ask for performance.
Want full control at your fingertips? Add the Stone Valvetronic System Single Valve to operate the valve remotely. The plug and play OBDII controller makes installation straightforward.
Sound and performance you will love
Expect a deeper tone, sharper throttle response and the iconic Stone Exhaust note without intrusive drone. This system is engineered to flow efficiently while maintaining daily refinement, making it perfect for spirited road use and long journeys alike.
Fitment and compatibility – BMW N20 engine
BMW 3 Series
- F30 328i 2011 onwards
BMW 4 Series
- F32 428i and 428i xDrive 2012 onwards
- F33 428i and 428i xDrive 2013 onwards
- F36 428i and 428i xDrive 2013 onwards
Options and part numbers
- AP501 Single Exit left with twin tailpipes
- AP512 Dual Exit with single tailpipe
- AP512Q Dual Exit with quad tailpipes
Fitted photos
See the Stone Exhaust BMW N20 F30 F32 F33 F36 cat back valved system installed:
R&D and manufacturing
Stone Exhaust engineers 3D scan OEM parts to analyse pipe diameter, routing and bend angles, then simulate gas flow, thermal and pressure zones to refine performance. The result is an integrally moulded exhaust with accuracy to within 0.025 mm.
A 7 axis CNC bending machine achieves up to 98 percent roundness with low outer wall wear at tight bends, minimising flow loss and preventing weld fracture. Combined with crisscross and overlapping welding at high heat zones and precise direct spot welding, you get strength, reliability and a beautiful finish.
What our customers say
We have fitted and tested these Stone cat back systems in house and customer feedback has been outstanding. Owners praise the OEM perfect fit, high quality craftsmanship, richer exhaust note and the lack of motorway drone. It is exactly how a BMW F30 328i or F32 428i should sound.
Fitting and installation
Professional fitting is recommended. Nforcd offers expert installation at our Warwickshire workshop. Request a fitting quote at Sales@nforcd.com.
Warranty
Stone Exhaust 2 year warranty.
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