Stone Exhaust BMW B48 G30 G31 520i OEM Integrated Valved Cat‑Back Exhaust System
Part Number: AP527A – requires original bumper
Transform your BMW 5 Series with the Stone Exhaust BMW B48 G30 G31 520i OEM integrated valved cat‑back exhaust. This is the ultimate BMW 520i G30 G31 cat‑back exhaust upgrade for owners who want a deeper, sportier sound, improved exhaust flow and premium build quality with Valvetronic valve control. Enjoy quiet comfort for daily driving with the valve closed, then unleash a sharper, more aggressive tone with the valve open. Designed for the B48 engine and engineered to integrate seamlessly with the OEM valve system, this valved cat‑back exhaust delivers the perfect blend of performance, sound and refinement.
We have fitted and used this system ourselves and our customers have been consistently impressed with the fit, finish and sound quality. If you are searching for a BMW G30 520i exhaust, G31 520i Touring exhaust, BMW B48 valved exhaust or 520i catback exhaust UK, this Stone Exhaust system is the smart choice.
Key benefits
- OEM integrated valve control – Valvetronic system retains factory style operation for stealth or sport at the touch of a button
- Plug and play OBDII controller for simple valve management
- One piece design for precise fitment and optimal flow
- Machine welding with exceptional consistency and finish
- In house R&D with 3D scanning and reverse engineering for accuracy and reliability
- Engineered for BMW 520i G30 G31 B48 – the ideal BMW 520i cat‑back exhaust upgrade
OPF compatibility
Stone offers an OPF delete option which can be included free of charge, allowing installation of the Stone cat‑back exhaust on OPF equipped cars without triggering an error code. Please check local regulations and vehicle use requirements.
Developed for performance and precision
R&D and 3D scanning – Stone Exhaust engineers scan OEM components to analyse pipe diameter, routing and bend geometry on the BMW B48 G30 G31 520i, then iterate using 3D flow simulation to optimise exhaust gas velocity, pressure zones and thermal management.
7 axis CNC bending – State of the art forming achieves up to 98 percent roundness with minimal outer bore wear at 180 degrees. This reduces turbulence and helps prevent weld stress points. Combined with 3D scanning, the result is exceptional accuracy with tolerances targeted under 0.025 mm.
Advanced welding – Crisscross and overlapping techniques are used on high heat flanges for strength and durability, while direct spot welding via mechanical arms delivers deeper, more consistent penetration. The outcome is a robust, beautifully finished BMW G30 G31 520i performance exhaust.
Compatibility
BMW 5 Series B48 engine
- G30 520i 2016 to 2019
- G31 520i 2016 to 2019
Perfect pairing
This exhaust system is often purchased with the Stone Exhaust BMW B48 G20 G30 Catless Performance Downpipe 330i 520i 530i or the Stone Exhaust BMW B48 G20 G30 Eddy Catalytic Performance Downpipe 330i 520i 530i for a complete BMW B48 exhaust upgrade.
Warranty
Stone Exhaust 2 year warranty
Professional fitting
For expert installation, book a fitting with Nforcd in Warwickshire. Request a quote at Sales@nforcd.com.
Why buy from Nforcd
Trusted UK supplier for BMW G30 G31 520i exhaust upgrades. We have installed this Stone Exhaust valved cat‑back on customer cars and feedback has been superb, praising the OEM integration, premium finish and the addictive exhaust note. Shop with confidence for genuine Stone Exhaust UK parts and specialist support.