Ford Fiesta ST Mk8 Tuning Guide

Fiesta ST Mk8 Tuning Guide

The Ford Fiesta ST Mk8 is a popular choice among enthusiasts looking for a small, agile hot hatch that offers a balance of performance and practicality. While the standard 1.5-litre EcoBoost engine is already a strong performer, many owners seek to further enhance their Fiesta ST with tuning and upgrades. If you’re considering tuning your Mk8 Fiesta ST, it’s important to understand the different options available, the hardware required, and the benefits each modification brings.

In this guide, we’ll break down the most popular tuning options for the Fiesta ST Mk8, helping you make informed decisions on how to improve the performance of your car.

1. Performance Tuning: ECU Remap (Chip Tuning)

One of the most straightforward and effective ways to increase the power of your Fiesta ST Mk8 is through an ECU remap, also known as chip tuning. This involves modifying the car’s engine control unit (ECU) to optimise the performance settings, allowing the engine to produce more power and torque.

• Benefits: An ECU remap can increase horsepower by up to 30bhp and torque by around 50Nm, improving throttle response, mid-range power, and overall acceleration. It can also improve fuel efficiency in certain driving conditions.
• Hardware Required: Typically, an ECU remap requires no additional hardware, but some tuners may recommend upgrading the intercooler or intake system for maximum gains.
• Considerations: Ensure the remap is done by a reputable tuner to avoid engine damage or reduced reliability. It’s also important to keep in mind that any remap could impact your warranty, so check with your dealer first.

2. Intake System Upgrade

Upgrading the intake system is a popular choice for increasing airflow into the engine, which can lead to more power and a more responsive throttle. The standard intake system on the Mk8 Fiesta ST can be restrictive when it comes to maximizing power.

• Benefits: A high-flow intake, such as an aftermarket air filter or a cold air intake system, allows more air into the engine, improving combustion and performance. This can lead to gains in horsepower, particularly when paired with an ECU remap. Some intakes also improve engine sound, giving your car a more aggressive tone.
• Hardware Required: Aftermarket cold air intake kits or high-flow panel filters, such as those from K&N, AIRTEC, or Pipercross.
• Considerations: When upgrading the intake system, make sure to choose a quality kit that is designed for your specific model. Poor-quality filters or incorrect installations can lead to issues with engine performance or reliability.

3. Exhaust System Upgrade

Upgrading the exhaust system is another popular modification that not only improves performance but can also enhance the sound of your Fiesta ST. A less restrictive exhaust system allows for better flow of exhaust gases, reducing backpressure and improving turbo efficiency.

• Benefits: A larger or less restrictive exhaust system can free up horsepower, particularly when combined with other performance modifications like a remap. It can also improve throttle response and acceleration. Many owners also opt for a sports exhaust to achieve a more aggressive exhaust note.
• Hardware Required: Options include sports downpipes, GPF deletes and cat-back exhaust systems. Brands like Milltek, Scorpion, and Cobra offer exhaust systems designed specifically for the Mk8 Fiesta ST.
• Considerations: Make sure any exhaust modification is legal in your area and complies with local noise regulations. Some exhaust systems, particularly those without a catalytic converter, may be too loud or illegal for road use in some regions. In the UK, any change to the emission control system (GPF pipe, downpipe) can be an MOT failure. 

4. Turbo Upgrade

If you're looking for significant power gains, upgrading the turbocharger can offer substantial performance improvements. The stock turbo on the Fiesta ST Mk8 is good for daily driving and moderate tuning, but for owners seeking 300+ horsepower, a turbo upgrade may be necessary.

• Benefits: A larger turbo will allow the engine to breathe more freely, increasing boost levels and ultimately power. A bigger turbo will provide more top-end power, making it an ideal option for those interested in track days or more aggressive tuning.
• Hardware Required: Aftermarket turbos from brands such as Garrett, Turbo Technics, or Mountune offer direct-fit options for the Fiesta ST Mk8. Along with the turbo, additional modifications such as a larger intercooler, upgraded fuel injectors, and an upgraded exhaust may be necessary to support the increase in power.
• Considerations: A turbo upgrade is a more involved modification and can require supporting upgrades to other engine components. It’s also an expensive option and may require professional installation.

Please note the Mk8 Fiesta ST is still undergoing development from tuning companies, the maximum power we have seen is around 320bhp. It is advised to "build" or re-inforce your engine with pistons, rods, bearings, head studs, and main studs, in order to cope with this power level. 

5. Suspension Upgrades

To fully take advantage of the extra power, upgrading the suspension is crucial for improving handling and ensuring the car stays planted on the road. The Fiesta ST Mk8 is already known for its great handling, but performance suspension upgrades can further enhance cornering ability, stability, and comfort.

• Benefits: A performance suspension setup, such as coilovers or upgraded shock absorbers, can improve ride quality, reduce body roll, and allow for better handling at higher speeds. It can also lower the ride height, giving the car a more aggressive stance and improving aerodynamics.
• Hardware Required: Coilovers, upgraded shocks and struts, or performance springs from brands like Bilstein, Eibach, or KW. Anti-roll bars or strut braces are also popular additions to further enhance handling.
• Considerations: When upgrading the suspension, consider how the changes will impact daily driving comfort. Coilovers can provide excellent adjustability, but they may result in a firmer ride. Make sure to properly align the car after any suspension modifications to avoid uneven tyre wear.

6. Brake System Upgrades

With the added power from tuning, upgrading the brake system is an important step to ensure the car can handle the increased performance. Improved braking can reduce stopping distances, prevent brake fade, and enhance overall driving safety.

• Benefits: Upgrading to larger, performance-focused brake discs, along with upgraded pads and braided brake lines, can improve braking response and heat dissipation. For serious track use, you might also consider performance calipers.
• Hardware Required: Upgraded brake discs, performance pads, braided brake lines, and potentially larger calipers from brands like Brembo, EBC, or V-Maxx.
• Considerations: Brake upgrades can be costly, but they are essential for cars that see heavy driving or track use. Keep in mind that high-performance brake components may be noisier or create more brake dust than standard parts.

7. Intercooler Upgrade

An intercooler is responsible for cooling the compressed air coming from the turbocharger before it enters the engine. Upgrading the intercooler can improve the intake air temperature, leading to better combustion and more power.

• Benefits: A larger or more efficient intercooler can help lower intake temperatures, reducing the risk of engine knock and improving performance during hard driving or in hot conditions. This can be particularly beneficial if you're running higher boost levels or have made other performance upgrades.
• Hardware Required: Performance intercoolers from companies like AIRTEC Motosport, Wagner Tuning, or Forge Motorsport offer direct-fit replacements that can provide better cooling efficiency.
• Considerations: While upgrading the intercooler provides clear performance benefits, it can be an expensive modification. Be sure to choose a high-quality intercooler to avoid potential installation or fitment issues.

Conclusion

Tuning your Fiesta ST Mk8 can take your driving experience to the next level, whether you're looking for more power, better handling, or a more aggressive sound. Start with simpler modifications like an ECU remap, intake upgrade, and exhaust system, and then progress to more advanced options like turbo upgrades, suspension enhancements, and brake system upgrades. Always ensure you’re using quality parts and working with experienced professionals when tuning your car. By choosing the right upgrades for your goals, you can create a Fiesta ST Mk8 that delivers improved performance while maintaining reliability.