Stone Exhaust BMW B48 F30 F31 F32 F33 F36 OEM Integrated Valved Catback Exhaust System for 320i and 420i
Upgrade your BMW 320i or 420i with the Stone Exhaust OEM Integrated Valved Catback Exhaust System and unleash the sound, flow and response your B48 engine deserves. Developed with 3D scanning and reverse engineering of the factory system, this cat-back delivers 100 percent OEM fitment, a deeper Stone signature exhaust note with no drone, and proven performance on Stone’s in-house dyno. Perfect for BMW F30 320i, F31 320i Touring, F32 420i Coupe, F33 420i Convertible and F36 420i Gran Coupe owners who want a premium, valved cat back exhaust upgrade that looks factory yet sounds phenomenal.
Available now from Nforcd in the UK. We have installed and used this system ourselves, and customer feedback on the tone, build quality and fitment has been outstanding.
Why choose the Stone Exhaust valved catback for your BMW 320i or 420i
- OEM Integrated Valve technology for factory-like valve control via your ECU
- Optional Stone Valvetronic System available for remote valve control
- Plug and play OBDII controller when adding Valvetronic
- One piece design for optimal flow and easy fitment
- Mechanical welding with precision, crisscross and overlapping techniques for durability
- 3D scanning and reverse engineered for 100 percent OEM fitment
- Dyno developed in house by Stone Exhaust for real performance gains
- Eliminates the typical drone found on many standard exhaust systems
Valve control options
OEM Integrated Valve: works just like stock. Your BMW’s ECU controls opening and closing automatically for everyday comfort and performance when you want it.
Optional Stone Valvetronic System: add single valve remote control with a plug and play OBDII controller. Open or close the valve at will for quiet cruising or a more aggressive sound.
Compatibility - BMW B48 engine
BMW 3 Series
- F30 320i and 320i xDrive 2011+
- F30 LCI 320i and 320i xDrive 2014+
- F31 320i 2011+ and 320i xDrive 2012+
- F31 LCI 320i and 320i xDrive 2014+
BMW 4 Series
- F32 420i and 420i xDrive 2013+
- F32 LCI 420i and 420i xDrive 2016+
- F33 420i 2013+ and F33 LCI 2016+
- F36 420i and 420i xDrive 2013+
- F36 LCI 420i and 420i xDrive 2016+
Part numbers and tailpipe configurations
- AP502B48 - Single exit with left twin tailpipes, requires original bumper
- AP502NB48 - Dual exit with twin tailpipes, requires 340i or 440i bumper
- AP502NQB48-8200CG - Dual exit with quad tailpipes, requires M Sport bumper
Sound and dyno
BMW N20 B48 F30 320i with Stone Exhaust OEM DP plus Valvetronic Catback System
BMW N20 F36 420i full exhaust system sound
Dyno result
Installed photos
Engineering that makes the difference
R and D and 3D scanning
Stone Exhaust engineers 3D scan OEM components to understand flow paths and constraints, then refine pipe diameter, routing and bend angles for the B48 platform. Using simulation of exhaust gas flow, thermal behaviour and pressure zones, they iterate until optimum performance is achieved.
7 axis CNC bending
Constructed with a 7 axis CNC bending machine for exceptional precision. Stone achieves up to 98 percent roundness with minimal outer bore wear at tight 180 degree bends, reducing flow restriction and preventing weld fracture. With CNC bending, reverse engineering and 3D design scanning, the exhaust pipe is integrally moulded with accuracy error under 0.025 mm.
Advanced welding
Crisscross and overlapping welding expands weld width and penetration at high heat areas such as the turbo flange and downpipe interface, increasing endurance and tolerance. Direct spot welding by mechanical welding arms improves strength and consistency for a finish that is both robust and beautiful.
Warranty
Stone Exhaust 2 year warranty.
Professional fitting
We recommend professional installation. Nforcd offers expert fitting at our Warwickshire facility. Request a fitting quote at Sales@nforcd.com.
Search friendly terms
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