Key Features of Mercedes AMG A45(S) M139 Downpipe:
Engineered for high-performance M139 builds, BlackBoost Downpipes deliver enhanced airflow, precision fitment, and race-ready reliability for those looking to buy Mercedes AMG A45S Downpipe.
Key features include:
- Beautiful Racing Exhaust note
- Huge exhaust flow improvement
- Completely Bypass Primary and secondary Catalytic
- Converters DPF & OPF*
- High Power/Torque Gains depending on mods
- Support power level proven over 1000 WHP
- Reduces back pressure on Turbo applications
- Built entirely in low carbon 304 Stainless Steel
- Mandrel-bent with laser-cut components
- Handmade Tig welded in House
- Bolt-on Plug and Play installation
- Compatible With BlackBoost and other Turbo Upgrades
Not Street Legal. For race use only. Requires a tune.
Frequently Asked Questions
Will a Mercedes AMG A45S W177 Downpipe make a noticeable difference without upgrading the turbo?
Yes. The M139 2.0L turbo engine benefits from reduced exhaust restriction, allowing the turbocharger to operate more efficiently. A high-flow catless downpipe can improve exhaust velocity, throttle response, and overall engine character, especially when paired with supporting modifications and ECU tuning.
Does installing a catless downpipe change the AMG A45S exhaust sound more than a cat-back exhaust?
For many enthusiasts, yes. The downpipe sits close to the turbocharger, meaning removing the factory catalytic restrictions can significantly change the exhaust tone, making the M139 sound sharper, louder, and more aggressive while also enhancing turbo spool sounds.
Do I need a Stage 2 tune after fitting a Mercedes AMG A45S M139 Downpipe?
A tune is highly recommended after installing a catless downpipe. Removing the factory catalytic system can trigger a check engine light, and ECU calibration helps the engine take advantage of the improved airflow while optimising performance.
Why choose a thermally insulated downpipe for the AMG A45S W177?
A thermally insulated downpipe helps retain exhaust heat within the system while reducing radiant heat transfer into the engine bay. This can help protect nearby components, control under-bonnet temperatures, and support more consistent performance during repeated high-load driving.
Can the Mercedes AMG A45S W177 M139 Downpipe support future performance upgrades?
Yes. A quality high-flow downpipe is often installed as part of a larger performance build. Its improved exhaust flow makes it suitable for vehicles running upgraded tuning packages, intake systems, turbo upgrades, and other supporting modifications designed to increase power output.