Description
High Flow Engineering S55 Decat Downpipes Performance Exhaust Upgrade
Unlock the full potential of your BMW M4 F82 with the HFE S55 3″ Decat Downpipes. Designed to replace the restrictive factory catalytic converters, these high-flow downpipes significantly reduce exhaust backpressure, improve turbo efficiency, and allow the S55 engine to deliver stronger performance and sharper throttle response — particularly on tuned vehicles.
⚠ IMPORTANT – ROAD USE, EMISSIONS & MOT NOTICE
These decat downpipes remove the factory catalytic converters and are intended for off-road or motorsport use only. They are not UK emissions compliant and will result in a UK MOT emissions failure. ECU tuning is strongly recommended after installation.
Key Features＋
- High-Flow 3″ Decat Design: Removes restrictive OEM catalytic converters.
- Improved Turbo Response: Reduces backpressure for faster spool.
- Performance-Grade Stainless Steel: Built for durability and heat resistance.
- Mandrel-Bent Tubing: Smooth internal transitions for optimal flow.
- Enhanced Exhaust Tone: Deeper, more aggressive sound under load.
- Direct-Fit Installation: Designed to replace OEM downpipes without modification.
Why Upgrade S55 Downpipes?＋
- Factory catalytic converters are a major restriction on tuned S55 engines.
- Reduced backpressure improves power delivery and torque response.
- Essential supporting modification for Stage 2 setups.
- Improves exhaust gas flow at high RPM.
- Pairs perfectly with upgraded intakes and charge pipes.
Technical Specifications＋
- Material: High-grade 304 stainless steel
- Configuration: Decat (no catalytic converters)
- Construction: Mandrel bent & welded
- Fitment: Direct OEM replacement
- Engine: S55 Twin Turbo
Vehicle Compatibility＋
- BMW M4: F82 Coupe (2014–2020)
✔ S55 twin-turbo engine only
✔ Compatible with factory and most aftermarket exhaust systems
✔ ECU tuning required
Installation＋
- Remove factory downpipes and catalytic converters.
- Install HFE decat downpipes using OEM mounting locations.
- Check clearance and secure all connections.
- ECU remapping required prior to driving.
- Professional installation strongly recommended.
Explore more from our collection.
Reviews
There are no reviews yet.