MST Performance Air Intake Kit – Ford Focus MK3 ST / RS (MST-FO-MK309)
The MST Performance air intake kit is a straightforward performance upgrade for the Ford Focus MK3, MK3.5, Focus ST and Focus RS. It replaces the restrictive factory airbox setup with a free-flowing induction system, giving your engine a better supply of air – which is one of the simplest ways to improve throttle response and release a little extra power.
This kit is designed to fit neatly into the existing engine bay space, making installation manageable for most enthusiasts without specialist tools. The included heat shield and bonnet seal help keep hot engine air away from the filter, so you’re drawing in cooler, denser air where it matters most.
What’s Included
- Black powder-coated airbox lid and heat shield with bonnet seal
- High-flow red dry pleated air filter
Performance Gains
On the dyno, this kit has shown gains of between 13 and 22hp depending on the vehicle and its state of tune. If your Focus is already running an ECU remap (a software tune that adjusts the engine’s settings), this kit works well alongside that – a tuned engine will generally benefit more from improved airflow than a completely standard one. On a stock vehicle, expect a noticeable improvement in throttle response and a more satisfying induction sound, rather than dramatic power gains.
The dry pleated filter is easy to remove, inspect and clean, keeping long-term maintenance simple.
Vehicle Compatibility
This kit covers a wide range of Ford Focus models, including the MK2.5, MK3 and MK3.5, as well as the Focus ST 2.0T EcoBoost and Focus RS 2.3T EcoBoost. It also fits certain Volvo V40 models. Please use the vehicle lookup tool on this page or check the “Vehicle Fitment” tab to confirm this kit is correct for your specific model and year before purchasing. Note that Focus MK3.5 TDCI (diesel) models are excluded.
MST Performance are a well-regarded name in the performance induction market, known for using quality components and producing kits that are practical to fit and genuinely effective. This kit strikes a good balance between performance improvement, everyday usability and value for money.
Additional Information
| Weight | 4 kg |
|---|---|
| Dimensions | 62 × 48 × 27 cm |
| Brand |

