Why Install An Induction Kit?
Induction kits on cars are always a topic for debate amongst enthusiast owners.
Some love them, and some dislike them.
It all comes down to expectations.
One of the most immediate and noticeable differences you’ll experience is the enhanced engine sound. An induction kit helps you hear a deeper and sporty roar when you step on the gas, along with some lovely turbo whooshes to accompany it!
On the performance side of things, a high quality induction kit can enhance the throttle response and provide some modest power gains. While this won’t exactly transform the car, many owners do report a noticeable difference with the right induction kits.
It’s important to choose the right induction kit for your ST, as some of the cheap and low quality kits can actually have a detrimental impact on the car’s power!
With this in mind, we’re going to show you the best kits available on the market that produce a lovely sound and also contribute to improved performance.
Let’s get into it.
RamAir Performance Air Intake Kit

The RamAir induction kit is an excellent option if you are after top quality.
This kit will give your ST a lovely growl on the throttle along with all the addictive turbo sounds as you spool it up and lift off the throttle.
The kit comes with everything you need to install it, and uses a dry foam filter as opposed to an oiled air filter.
Dry foam filters are often preferred over oiled air filters as the oil can sometimes contaminate the MAF sensor, causing you issues.
The free flowing nature of the induction kit is designed to aid air flow, helping enhance the performance and throttle response.
Airtec Induction Kit

This kit is extremely popular among ST225 owners for it’s affordability and quality.
With this kit, you get a large 80mm foam cone filter to ensure maximum air flow for performance along with enhanced sounds.
This kit comes with everything you need to remove the restrictive standard airbox and swap this in. It also comes with a cold feed scoop which helps enhance air flow to the engine while also offering protection if you have RS vents fitted to the car.
If you are looking for enhanced sounds and performance on a tighter budget, this kit offers the best value.
K&N Induction Kit

K&N have made another excellent induction kit for the Focus ST225, that enhances performance and gives you those added sounds you crave.
As with the other kits, you get everything you need to make installation quick and straightforward.
You can’t go wrong with the quality of K&N, so if you can afford the extra money for this induction kit then you won’t be disappointed.
Pipercross Panel Filter

Not quite an induction kit, but definitely worth mentioning if you are after an alternative way to enhance performance from the air intake on a budget.
The Pipercross performance panel filter stands as an excellent alternative and is 30% less restrictive than the standard filter.
The panel filter’s design enables better airflow into the engine, contributing to a smoother throttle response and a marginal improvement in power output.
This filter is extremely easy to install as it simply replaces the OEM air filter inside the standard airbox, so installation takes mere minutes. It is also reusable so you can remove it and clean it at every service without having to buy a new one.
These types of filters don’t tend to contribute that much to enhanced sound, so if sound is what you are after then you are better opting for an induction kit.
The Verdict
Induction kits remain an extremely popular modification among ST225 owners for the lovely sounds they make and minor boosts they can provide in terms of performance.
All the kits mentioned in this guide are fantastic options and you can’t go wrong with any of them. If you are on a budget and are after enhanced sound, the Airtec kit comes in at the lowest price while still providing excellent value.
If you can afford to spend a little more, then RamAir is the next best option followed by K&N.
If you don’t want to fork out for an induction kit and aren’t too fussed about missing out on the increased sounds, then a performance panel filter from Pipercross is a worthwhile upgrade.
Happy modding!