Stone Exhaust BMW N20 Catless Downpipe for F20 F22 F30 F32 F36 models. Decat downpipe upgrade for 120i, 220i, 320i, 328i, 420i and 428i
Unlock more performance and sound from your BMW N20 with the Stone Exhaust catless downpipe. This BMW N20 decat downpipe is engineered for the F20, F21, F22, F23, F30, F31, F32, F33 and F36 platforms, covering 120i, 220i, 228i, 320i, 328i, 420i and 428i. It is the perfect BMW N20 performance exhaust upgrade for drivers seeking improved exhaust flow, reduced backpressure and a more aggressive exhaust note. Designed using 3D scanning, reverse engineering and precision manufacturing, this Stone Exhaust downpipe delivers true OEM fitment and track-proven reliability.
We have supplied and fitted Stone Exhaust systems for years and the quality, fit and finish are consistently excellent. Customers choosing this BMW N20 catless downpipe report superb build quality, precise fitment and a noticeable transformation in exhaust character. If you want the best BMW N20 downpipe upgrade for your F Series 1 Series, 2 Series, 3 Series or 4 Series, this is the one.
Why choose the Stone Exhaust BMW N20 catless downpipe
- Catless downpipe for N20 engines: F20, F21, F22, F23, F30, F31, F32, F33, F36
- Suitable for 120i, 220i, 228i, 320i, 328i, 420i and 428i
- Designed to improve exhaust flow and turbo efficiency for performance and sound
- Unique flex section to prevent cracking from extreme heat cycles
- Crisscross and overlapping welding to strengthen the turbo flange under high temperature stress
- One piece bend design for smoother flow and fewer potential failure points
- Machine welded with robotic arms for precise, clean, high-penetration welds
- In-house research and development with 3D scanning and reverse engineering
- 100 percent OEM fitment, direct replacement for the factory downpipe
Engineering that makes the difference
Stone Exhaust uses flow velocity measurement in 3D, one piece bend pipes and mechanical welding arms to create a clean internal surface, minimising turbulence and welding residue. The result is exceptional exhaust gas efficiency from the turbo outlet through the downpipe.
R&D and 3D Scanning
OEM components are 3D scanned to map routing, pipe diameter and bend geometry, identifying restrictions and weaknesses in the factory N20 exhaust. 3D simulation software models gas flow, heat and pressure zones, with iterative improvements until optimal performance is achieved.
7 Axis CNC Bending
Constructed using a 7 axis CNC bending machine for aerospace-grade precision. Industry-leading 98 percent roundness is maintained with only 25 percent outer bore wear at 180 degrees, reducing flow disruption and eliminating common fracture points. Combined with 3D scanning and reverse engineering, Stone produces integrally moulded pipes with accuracy within 0.025 mm.
Crisscross and Overlapping Welds
The turbo to downpipe flange experiences extreme temperatures. Stone’s crisscross and overlapping weld technique increases weld width and penetration, enhancing durability and tolerance under heat stress.
Direct Spot Welding by Robotic Arms
Robotic welding achieves consistent, high precision welds with exceptional penetration for strength and longevity. The end product is robust, reliable and built to perform.
Compatibility
Engine: BMW N20
BMW 1 Series
- F20 120i (2010+)
- F20 LCI 120i (2014+)
- F21 120i (2010+)
BMW 2 Series
- F22 220i (2012+) / 228i (2012+) / 228i xDrive (2013+)
- F23 220i (2014+)
BMW 3 Series
- F30 320i / 328i / 328i xDrive (2011+)
- F30 LCI 320i / 328i / 328i xDrive (2014+)
- F31 320i (2011+) / 320i xDrive (2012+) / 328i (2011+) / 328i xDrive (2012+)
- F31 LCI 328i xDrive (2014+)
BMW 4 Series
- F32 420i / 420i xDrive (2013+) / 428i / 428i xDrive (2012+)
- F33 420i / 428i / 428i xDrive (2013+)
- F36 420i / 420i xDrive / 428i / 428i xDrive (2013+)
Part number
A205P
Warranty
Stone Exhaust 2 year warranty.
Professional fitting
For fitting and installation, we recommend Nforcd in Warwickshire. Request a quote at Sales@nforcd.com.
Important note
This is a catless decat downpipe. For motorsport and off road use only where permitted. Check local laws and regulations before purchase and installation.
Photos
Video
BMW F36 N20 420i Full Exhaust System Sound
Search terms: BMW N20 catless downpipe, BMW N20 decat downpipe, BMW F20 downpipe, BMW F22 downpipe, BMW F30 downpipe, BMW F32 downpipe, BMW F36 downpipe, 120i downpipe, 220i downpipe, 228i downpipe, 320i downpipe, 328i downpipe, 420i downpipe, 428i downpipe, BMW N20 performance exhaust, Stone Exhaust downpipe UK, Nforcd BMW downpipe, BMW turbo downpipe upgrade, BMW N20 exhaust upgrade.