Stone Exhaust Catless Downpipe for BMW B46D Engines – G20 G21 G22 G23 G26 G30 G01 G02 OPF Models
Unlock more flow, faster turbo response and a harder-hitting exhaust note with the Stone Exhaust catless downpipe for BMW B46D engines. Engineered for G‑series BMW 320i, 330i, 420i, 430i, 530i xDrive and X3/X4 20i/30i applications including OPF and GPF equipped cars, this one-piece, machine-welded downpipe delivers true performance with OEM-like fitment. Part Number: A224NP.
If you are searching for BMW G20 330i downpipe, BMW 320i downpipe, BMW G22 430i downpipe, BMW 420i downpipe, BMW G30 530i downpipe, BMW X3 20i downpipe, BMW X4 20i downpipe, BMW B46 downpipe, B46D decat downpipe, OPF downpipe, GPF downpipe, catless downpipe for BMW, Stone Exhaust downpipe or performance downpipes for BMW G series, you have found the proven choice.
Why choose the Stone Exhaust A224NP catless downpipe
- Catless performance downpipe for BMW B46D engines including OPF and GPF models
- One-piece mandrel-bent design for maximum flow and reliability
- Mechanical, precision machine welding for consistent penetration and strength
- Unique flex section to control movement and reduce stress from extreme heat
- Crisscross and overlapping welds to reinforce the turbo flange under high temperature
- 3D flow velocity analysis and reverse-engineered fitment from OEM parts
- 7‑axis CNC bending for exceptional roundness and smooth internal radii
- 100% OEM fitment with factory mounting points maintained
Engineered for flow, built for durability
Stone Exhaust uses state-of-the-art 3D simulation to map exhaust gas movement, thermal zones and pressure rises, then optimises pipe diameter, routing and bend angles for the B46D platform. The catless, one-piece mandrel-bent construction reduces weld joints that can disrupt gas flow, helping the turbocharger operate more efficiently.
A 7‑axis CNC bending process achieves up to 98% roundness with minimal outer-bend thinning at 180 degrees, while precision machine welding and direct spot welding by mechanical arms deliver consistent, high-strength joints. Crisscross and overlapping weld techniques increase flange endurance where temperatures can soar, giving long-term reliability in demanding conditions.
Real-world results with Nforcd
We have fitted these Stone Exhaust downpipes on customer BMW B46D cars across G20 330i, G22 430i and G01 X3 20i platforms and have been consistently impressed by the OEM-level fit, clean welds and the freer-flowing feel on the road. Customers love the sharper response and more engaging exhaust character that a well-engineered catless downpipe brings.
Compatibility
Engine: BMW B46D
BMW 3 Series
- G20 320i(x) / 330i(x) 2017+
- G21 320i(x) / 330i(x) 2018+
BMW 4 Series
- G22 420i(x) / 430i(x) 2020+
- G23 420i(x) / 430i(x) 2020+
- G26 420i(x) / 430i(x) 2020+
BMW 5 Series
- G30 530i xDrive 2019+
BMW X Series
- G01 X3 20i(x) / 30i(x) 2017+
- G02 X4 20i(x) / 30i(x) 2017+
Technical highlights
- Reverse-engineered via 3D scanning of OEM components
- 3D flow simulation to optimise gas velocity and turbine efficiency
- 7‑axis CNC bending, integrally moulded pipe, accuracy error under 0.025 mm
- Direct spot welding by mechanical arms for precision and repeatability
Part number
A224NP
Fitting
Professional installation recommended. For fitting in the UK, we can take care of everything at Nforcd in Warwickshire. Request a fitting quote: Sales@nforcd.com.
Manufactured by
Stone Exhaust
Warranty
Stone Exhaust 2 Year Warranty
Emissions and legal notice
Catless downpipes may not be road legal in all regions. Check local regulations and MOT requirements before purchase and installation. The purchaser is responsible for ensuring compliance with all applicable laws where the product is used.
Search-friendly terms
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