Tuning the Ford Focus ST Mk4

Discover how to take your Ford Focus ST Mk4 to new heights of performance and style with our comprehensive guide to tuning and modification. From unlocking the hidden power of your engine to enhancing suspension, braking, and aesthetics, we’ll walk you through the process step by step. Whether you’re a seasoned enthusiast or just starting your tuning journey, this guide will provide you with valuable insights and practical tips to make your Mk4 ST stand out from the crowd.

The Best of the Breed: Mk4 Focus ST

The Ford Focus has been a staple in the world of car tuning for 25 years, but its days are sadly numbered. With the switch to electric vehicles looming, the Focus is expected to cease production in 2025. However, before it bids farewell, the Mk4 Focus ST has emerged as the ultimate incarnation of this beloved model. While its styling may lack the overt sportiness of its predecessors, the Mk4 delivers in terms of technology, driving experience, and build quality. It’s a grown-up hot hatch that doesn’t scream for attention but still packs a punch. And with an already thriving aftermarket scene, there are plenty of upgrades available to tune your ST to the next level.

Unleashing the Power: Tuning the Mk4 Ford Focus ST EcoBoost Engine

The Mk4 ST shares its 2.3-litre EcoBoost engine with the previous generation Focus RS but with some noteworthy improvements. Notably, the ST’s EcoBoost has proven to be more robust and reliable. A simple first-stage remap can bring the power up to 325bhp with 50bhp gains at 5400rpm. Tuning specialists like Mountune, Collins Performance, Revo, Dreamscience, Motorsport Developments, and Laird Performance all offer similar software upgrades, giving you the performance to rival even modified RS models.

Hardware upgrades such as intercoolers, cold air intake kits, and cat-back exhaust systems further enhance engine tuning. To unlock next-level performance, a sports catalytic convertor and sport gasoline particulate filter (GPF) are recommended.

Tuners like Mountune and Revo offer packages that push the power output to a staggering 360bhp to 405bhp and torque to 413lb.ft to 435lb.ft. In terms of cost, a first-stage remap and panel filter upgrade can range from £500 to £800. Hardware upgrades such as intercoolers and exhaust systems can range from £700 to £1500, depending on the brand and specifications. It’s important to note that these costs do not include installation or labour fees, which may vary depending on the tuning shop or specialist undertaking the work.

Transmission Upgrades

The stock six-speed manual transmission on the Mk4 ST is robust and handles increased power and torque well. However, companies like Helix offer clutch upgrades to handle even more torque for those seeking serious performance. Adding a well-weighted short-shift kit improves gear changes and is a worthwhile addition to any ST.

Ford Focus ST Mk4 Suspension Tuning

When it comes to suspension upgrades, the stock electronically controlled damping system of the Mk4 ST works well for most enthusiasts. However, for those seeking fine-tuned suspension settings or regular track use, investing in a set of coilovers is highly recommended.
Coilovers allow for precise adjustments in ride height, damping, and stiffness. Prices for coilover kits typically range from £1000 to £2000-plus, depending on the brand and specifications. Ford Performance coilovers (manufactured by KW) are also available through Ford dealerships. It’s worth noting that upgrading to coilovers will require an electronic damper delete module, which adds approximately £200 to the cost. For a more budget-friendly option, pairing lowering springs with the stock dampers can provide a noticeable improvement in handling without the need for more extensive modifications.

Stopping Power

When it comes to braking performance, the stock 330mm discs and twin-piston calipers are more than capable for most driving situations. Upgrading to performance pads and discs, along with braided lines for improved pedal feel, enhances their capabilities in fast road and occasional track sessions.
However, for spirited driving or track use, upgrading to a big brake kit can provide enhanced stopping power and fade resistance. EBC Brakes offers a two-piece fully-floating disc kit with four-pot calipers for £1370, while Revo’s Mono6 upgrade includes a massive 380mm disc and six-pot calipers for £2385. It’s worth noting that upgrading the brakes also involves replacing brake fluid, fitting braided lines, and potentially upgrading the rear pads, which can add to the overall cost.

Enhancing the Look

The Mk4 may still be in its early days, but there are already plenty of bolt-on aesthetic upgrades available to give your ST a more aggressive appearance. From splitters and low line kits to spoiler extensions and vinyl wrapping, there are options to suit every owner’s taste and preference. These bolt-on modifications can add a touch of aggression and individuality to the stock ST without compromising its daily drivability or practicality.
It’s worth mentioning that more radical modifications like wide-arch kits are also available for those looking to create a truly unique show car. However, it’s important to note that these modifications may require significant additional investment and potential compromises in terms of practicality and usability.

Wheels and Tyres

The performance-oriented ST Edition comes equipped with lightweight 19-inch alloys, reducing unsprung weight by 10% at each corner compared to the stock alloys. These can be purchased directly from Ford, albeit in a different finish. Lower offsets like ET42/45 can provide a more aggressive stance, and there are numerous options available in both 19-inch and 20-inch sizes. However, it’s important to consider the trade-off between aesthetics and ride comfort. For track enthusiasts, dropping down to 18-inch wheels can improve handling and offer a wider selection of track-focused tyres. When it comes to choosing tyres, it’s crucial to invest in trusted, well-known brands for optimal performance and safety.

Personalizing the Interior

The interior of the Mk4 Focus ST already exudes a premium feel, with a level of build quality that rivals its German competitors. While there may not be much need for performance-oriented interior modifications, personalizing the cabin is all about individual taste. Upgrades such as aftermarket shift knobs, pedals, and interior trim can add a touch of personal flair to your ST.

Ford Focus ST Mk4 Tuning Guide

The Mk4 Ford Focus ST is the pinnacle of the Focus lineage, offering a balance of power, refinement, and practicality. With a robust tuning scene and plenty of aftermarket support, taking your ST to the next level has never been easier. From remaps and hardware upgrades to suspension tuning and aesthetic enhancements, there are endless possibilities for getting the most out of your Mk4 ST. So why settle for the ordinary when you can transform your car into something truly extraordinary? Embrace the world of tuning, and let your Mk4 ST shine on both the road and the track.