MST Performance Audi S4 S5 (B9) 3.0T (2019+) Air Intake Kit

MST Performance Audi S4 / S5 (B9) 3.0T Air Intake Kit (2019+) – MST-AD-A406

If you want more from your Audi S4 or S5, improving the air intake is one of the most straightforward upgrades you can make. The MST Performance intake kit (MST-AD-A406) replaces the restrictive factory airbox on the B9 3.0T engine with a freer-flowing setup that helps the turbocharger breathe more efficiently – resulting in better throttle response, a more engaging induction sound, and a genuine improvement in performance.

What Does It Do?

Your car’s engine produces power by burning a mixture of fuel and air. The more efficiently air can reach the turbocharger (the device that forces extra air into the engine to boost power), the better the engine can perform. The standard airbox is designed with cost and noise reduction in mind, which means it can restrict airflow. This MST kit removes that restriction, allowing a greater volume of cold, dense air to flow directly to the turbo.

The result is sharper throttle response – meaning the car feels more immediate and reactive when you press the accelerator – along with a deeper, more pronounced induction sound under load. On the dyno (a machine used to measure engine power), this kit has shown gains of up to 12-14bhp, though real-world results will vary depending on the condition of your vehicle and whether it has been remapped or tuned.

What’s Included?

• Black powder-coated heat shield – helps keep intake air cool and away from engine heat
• Black silicone inlet pipe – durable, flexible and a direct fit to your existing setup
• Red dry pleated performance air filter – easy to clean and maintain, no oiling required
• Full fitting hardware and step-by-step instructions

Tuned or Standard – It Works Either Way

Whether your S4 or S5 is completely standard or already running a tune (a software remap to increase power), this intake kit is a worthwhile addition. On a standard car it delivers a noticeable improvement on its own. On a remapped car, ensuring the engine has unrestricted access to cold air helps the tune work more effectively and consistently.

Quality and Finish

MST Performance build their kits using quality components throughout. The black powder-coated heat shield and inlet pipe give a clean, purposeful look under the bonnet – a step up from the grey plastic of the standard airbox. The dry pleated filter is simple to service; unlike oiled performance filters, it requires no re-oiling treatment – just a clean when needed.

Fitment: This kit is designed for the Audi S4 and S5 B9 chassis fitted with the 3.0T engine (2019 onwards). Please use the vehicle lookup tool on this page or check the Vehicle Fitment tab to confirm compatibility with your specific model before purchasing.