Stone Exhaust BMW N13 F20 F21 Cat-Back Valvetronic Exhaust for 1 Series 116i 118i 120i
Upgrade your BMW 1 Series N13 with the Stone Exhaust Valvetronic Cat-Back System and unlock the soundtrack, response and everyday refinement your F20 or F21 deserves. Designed specifically for BMW 116i, 118i and 120i models with the N13 engine, this premium cat-back exhaust delivers a deep, refined tone with valves closed and an aggressive, motorsport-inspired note with valves open. OEM-level fitment, real-world performance gains and zero-drone cruising make this the ultimate BMW F20 F21 exhaust upgrade for UK road and track.
Developed by Stone Exhaust since 1998 and engineered using 3D scanning and reverse engineering of the OEM system, this cat-back is built for precision. It is dyno developed in-house to enhance power and throttle response, while the high-precision one-piece design and advanced welding techniques deliver durability and reliability you can trust.
Why choose this BMW N13 F20 F21 cat-back exhaust
- BMW 1 Series performance exhaust - F20 F21 116i 118i 120i N13
- Valvetronic valved cat-back exhaust - quiet when you want, loud when you need
- Plug and play OBDII valve controller - quick installation and simple operation
- Remote control with ON, OFF and AUTO modes - set valve operation by RPM in Auto mode
- One-piece design for optimal flow and precise OEM fit
- 3D scanning and reverse engineering for 100% OEM fitment accuracy
- Dyno developed in-house to improve performance and response
- Eliminates drone common on the standard BMW 1 Series exhaust
- Mechanical welding with precision - strength and reliability
- 7-axis CNC bending for smooth flow and consistent quality
Real-world benefits
With valves closed, enjoy a refined, drone-free drive for daily commuting. With valves open, unleash a sharper, sportier BMW N13 sound that transforms the driving experience. Our team has fitted and used this system, and customer feedback has been consistently positive on sound quality, fitment and the noticeable improvement in response.
Valvetronic control - simple, smart and switchable
- Remote-controlled valves - toggle ON, OFF or AUTO at the touch of a button
- Auto mode allows valve operation to be tied to a predefined RPM
- OBDII plug and play - no complicated wiring, quick install
Engineered for accuracy and durability
Stone Exhaust uses advanced 3D simulation to optimise gas flow, temperature and pressure zones before production. A 7-axis CNC bending process maintains exceptional roundness and consistency for smooth flow, while crisscross and overlapping welding, plus direct spot welding, increase strength at high-stress, high-temperature points.
Watch the Valvetronic system in action
Compatibility - BMW N13 engine
BMW 1 Series
- F20 116i, 118i, 120i - 2010+
- F21 116i - 2011+, 118i and 120i - 2012+
Part number
AP515NS - requires M135i rear bumper
Warranty
Stone Exhaust 2-year warranty
Professional fitting and support
For expert installation of your BMW F20 F21 valved cat-back exhaust, we recommend fitting with Nforcd in Warwickshire. Request a fitting quote at Sales@nforcd.com.
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