Stone Exhaust BMW Toyota B58D Catless Downpipe OPF for A90 Supra, G29 Z4 M40i, G20 M340i and G20 M340i xDrive - Part Number A223P
Looking for a B58 catless downpipe upgrade for OPF models that delivers real performance and perfect fitment. The Stone Exhaust B58D Catless Downpipe OPF is the go to choice for the Toyota GR Supra A90 and BMW G20 G21 M340i and G29 Z4 M40i. This high flow decat downpipe is designed for B58D engines with OPF GPF, unlocking superior exhaust flow, sharper throttle response and a more aggressive exhaust note while maintaining 100% OEM fitment. Ideal for A90 Supra downpipe upgrades, M340i downpipe upgrades and Z4 M40i downpipe upgrades.
At Nforcd we have installed and used Stone Exhaust hardware across our B58 builds and customer feedback has been consistently excellent. If you are searching for A90 Supra catless downpipe, BMW M340i catless downpipe, Z4 M40i catless downpipe, B58 OPF downpipe, B58D decat downpipe or G20 M340i xDrive downpipe, this A223P unit is the premium, precision engineered solution.
Key benefits
- Catless downpipe for B58D OPF GPF models - maximised exhaust flow and reduced back pressure
- Proven on A90 Supra, G29 Z4 M40i, G20 G21 M340i and G20 M340i xDrive applications
- Unique flex section helps prevent fatigue and cracking under extreme heat
- Crisscross welding at the turbo flange for strength and durability
- One piece bent design for smooth flow and minimal turbulence
- Mechanical robotic welding for precision and consistency
- 3D scanning and reverse engineering for exact OEM fitment
- Direct bolt on fit - no cutting, no modification, 100% OEM fitment
- Backed by Stone Exhaust 2 Year Warranty
Engineered for the B58D OPF
Stone Exhaust developed this B58D OPF catless downpipe using full reverse engineering. OEM parts were 3D scanned to determine optimal pipe diameter, routing and bend angles specific to the B58D exhaust layout found on the A90 Supra and G20 M340i platforms. Flow velocity simulation, thermal mapping and pressure zone analysis were used throughout R&D to refine the design for real world performance on OPF equipped models.
Manufacturing highlights
- 7 axis CNC bending achieves exceptional roundness and smooth radii for high flow
- Mechanical robotic welding delivers deep penetration and consistent quality
- Crisscross and overlapping weld techniques strengthen high temperature joints
- Integrally moulded one piece sections minimise welds inside the tube for cleaner flow
The result is a B58 catless OPF downpipe that feels responsive, sounds purposeful and installs like OEM. Customers choose Stone for its precision, durability and fit first time experience on B58D platforms.
Compatibility
Engine B58D with OPF GPF
Toyota
- GR Supra A90 3.0 B58D OPF
BMW
- G20 M340i and M340i xDrive B58D OPF
- G21 M340i xDrive B58D OPF
- G29 Z4 M40i B58D OPF
Part number and warranty
Part number A223P
Manufacturer Stone Exhaust
Warranty Stone Exhaust 2 Year Warranty
Fitting and support
Professional installation recommended. We offer in house fitting at Nforcd in Warwickshire. Request a fitted quote at Sales@nforcd.com.
Search friendly terms
Stone Exhaust B58 catless downpipe OPF, B58D decat downpipe, A90 Supra downpipe OPF, Toyota Supra MK5 A90 B58 downpipe, BMW G20 G21 M340i catless downpipe, BMW M340i xDrive downpipe, BMW Z4 M40i downpipe G29, B58 OPF GPF downpipe upgrade, A223P Stone downpipe, Supra A90 decat, M340i decat, Z4 M40i decat, B58D performance downpipe.
For off road or motorsport use only where local laws permit.