MST 6" Catted Downpipe GPF/OPF for BMW/Toyota B58 3.0T (BW-5808DP) – Max Efficiency Exhaust Upgrade
Elevate your BMW or Toyota B58 3.0T engine with the MST 6" Catted Downpipe GPF/OPF (BW-5808DP) — the world's largest diameter downpipe for unmatched exhaust flow and performance. Dyno-proven to add 18-25 HP and up to 28 ft/lb torque on stock vehicles, it reduces backpressure, lowers exhaust temps, and delivers thrilling sound while maintaining cleaner emissions with its 400-cell Euro 6 catalytic converter. Perfect for **B58 tuning** on M140i, 340i, Supra A90, and more!
Why Choose MST 6" B58 Catted Downpipe?
- World-Leading Design: 6" diameter for straight-pipe-like efficiency without the hassle
- Premium Catalyst: 400-cell Euro 6 high-flow cat (EPA #101709-CHN-1) for balanced performance and emissions
- No CEL Guarantee: Engineered to prevent check engine lights — backed by warranty
- GPF/OPF Compatible: Fits both equipped and non-equipped vehicles seamlessly
- High-Power Ready: Supports 800+ HP builds with reduced pressures and temps
- Versatile Fit: CNC adapters for turbo alignment; works stock or tuned
Compatible Vehicles (B58 3.0T Engine)
- BMW M140i F20 (2016+)
- BMW M240i / M240i xDrive F22 (2016+)
- BMW 340i / 340i xDrive F30/F31/G20 (2016+)
- BMW 440i / 440i xDrive F32/F33/F36/G22/G23/G26 (2016+)
- BMW 540i / 540i xDrive G30/G31 (2016+)
- BMW 740i / 740i xDrive G11/G12 (2016+)
- Toyota Supra A90/A91 (2019+)
- BMW M240i G42 (2022+)
Verify GPF/OPF status for your model. Contact support for custom fits.
Performance Gains – Dyno-Tested on Stock B58
| Upgrade | Horsepower Gain | Torque Gain | Key Benefits |
|---|---|---|---|
| MST 6" Catted Downpipe | 18-25 HP | 4 kgm | Lower EGTs, faster spool, aggressive sound; even more on tuned setups |
Gains at the wheels; varies by vehicle condition, fuel, and tune. Ideal for **BMW B58 downpipe upgrades**.
Key Specifications
- Diameter: 6 inches (largest available for B58)
- Catalyst: 400-cell Euro 6 metallic substrate
- Material: High-grade stainless steel for durability
- Connections: Precision CNC adapters for turbo fitment
- EPA Certified: Establishment #101709-CHN-1
- Weight: Optimized for lightweight performance
Installation – Bolt-On Ease
Professional or DIY install recommended. Basic tools needed; typical time: 1-2 hours. No major modifications required.
- Secure vehicle on lift/jack stands
- Disconnect O2 sensors and remove stock downpipe
- Align and bolt on MST downpipe with provided clamps/adapters
- Reconnect sensors and torque to spec
- Clear any codes and test drive
Pro Tip: Pair with a **B58 ECU tune** for 50+ HP total gains. Full install guides available post-purchase.
Warranty & Support
- 2-Year CAT Warranty: Free replacement if CEL triggered by catalyst (shipping on you)
- Process: Return old unit to original dealer for verification
- Shipping: DHL Express or FedEx; duties/taxes on buyer
- Returns: 30 days for unopened items; restocking fees apply
Frequently Asked Questions (FAQs) – B58 Downpipe
Will it cause a Check Engine Light?
No — our high-flow cat is designed to avoid it. Warranty covers any catalyst-related CELs.
Is it street-legal?
Off-road/race only. Not CARB/EPA compliant for on-road use in restricted areas.
GPF/OPF Delete Needed?
No — this version fits with GPF/OPF intact for emissions-friendly installs.
International Duties?
Buyer pays all import fees. U.S. orders may face tariffs on aluminum/steel parts — check with customs.
800 HP Compatible?
Yes — built for high-power B58 builds with reduced backpressure.
