It seems that every Comparison article in the automotive press these days is pitting the plucky-but-capable little Fiesta ST against all sorts of competition – from the more direct comparisons like the Fiat 500 Abarth and Mini Cooper S to apples-and-oranges comparisons like sending the Fiesta ST up against the Subaru BRZ/Scion FR-S/Toyota GT86 – which it’s evenly matched against – or beefier competition – like the E46 M3. With so many other cars seemingly wanting a piece, these few tuner tweaks to the Fiesta ST will make your car faster, handle better and more fun to drive, and maybe even allow you to embarrass a few people at the local Run-What-Ya-Brung night at the Dragstrip.

1. Tighten your hose clamps!


Fiesta ST Intake Hose Clamps Need Tightening. Photo by Shmi,

This Mod is the most cost effective of any because it’s FREE – it just costs a bit of your time. Take a 7mm and tighten the various clamps that secure the entire intake tract. Be sure to tighten the throttle body connection, intercooler inlet and outlet and airbox clamps – you’d be surprised at just how loose these clamps can be after as little as 600 miles! By doing this simple act, you’ve also ensured that you won’t see boost leaks later and your car will be running at its best. To tighten these down, you’ll need a 7mm socket and ratchet and a 7mm ratcheting wrench would be a fantastic idea.

Here are the connections you’ll need to check, from
Connection 1 – On the back of the engine looking up from underneath, there is a connection of a rubber hose going onto the outlet of the turbo charger.
Connection 2 – The other end of that rubber pipe goes down onto a thin looking metal pipe.
Connection 3 – This is the other end of the metal pipe. From under the car these 3 are easy to access. It connects the metal pipe to the rubber hose that goes to the intercooler.
Connection 4 – This connection is on the passenger side of the intercooler (looking head on at the car) a lot harder to access without removing the fascia.
Connection 5 – This one is the driver’s side of the intercooler. It can be hard to access without removing the fascia.
Connection 6 – This connects a rubber hose coming from the driver’s side of the intercooler and goes onto a plastic pipe that heads up towards the intake.
Connection 7 – This is the other end of the plastic pipe, It goes to a short peice of rubber hose just before the throttle plate (Hard to get to will probably need a 7mm wrench, not a socket)
Connection 8 – This is directly onto the throttle body. This can be hard to get to with all the AC pipes in the way, but not too hard.

2. Stop Truncating your Torque… with a Tune!

From the factory, the Fiesta ST comes with Torque Truncation in 1st, 2nd and reverse. This means that the car’s output is significantly hampered during those critical take-off gears. A tune, for instance, the Cobb AccessPort for Fiesta ST, utilizing Cobb’s Off-The-Shelf (OTS) tunes, disables these limiters – allowing you to get the most out of your Fiesta. While the HP gain is just 5% for a Plug-n-Play OBD II tuner on a stock Fiesta, the 15% torque increase (that’s around 30lb-ft) is something you’ll notice day to day – you’ll be downshifting less and find yourself with a harder “pull” at WOT. The added benefit of a device like an AccessPort is that it allows you to display up to 6 different readouts (choose from over 190 data sources!) and can datalog, and allows you to adjust your tuning as you perform more modifications later on. Dollar for dollar, it’s an excellent value for money, and this is an upgrade you’ll really feel on the “butt-dyno”. Be sure to check out our Expert Review of the Cobb AccessPort for Fiesta ST here.

3. Get More Grip With Wider Wheels & Tires

Photo Courtesy MKVIIST,


Photo Courtesy MKVIIST,

If there’s one thing the Fiesta ST needs more of, it’s hook-up and traction. By upgrading the Fiesta ST wheels with a wider set, for instance, a set of ESM-004 wheels in 4x108mm for Fiesta ST, wrapped in 225-series tires, will give you more of that grip you need. 225 series is about as wide as you can go on the Fiesta ST. Of course, you need to remember with tires, compound is important, so be sure you’re fitting a set of properly high performance tires. ModBargains offers several style wheels for the Fiesta, but should you not see what you’re looking for, contact a Modification Expert (714-582-3330) as they can likely provide what you’re looking for at a price that’ll earn your business.

4. Get Low With Sport Springs or Coilovers

Now this one may cause some debate, but really the correct answer for this comes down to personal preference and budget when it comes to choosing the right Suspension for your Fiesta ST.


If you’re the average daily-driver that occasionally autocrosses, a set of Sport Springs, paired with a sway bar (more on that later), is probably just right for keeping your daily driver comfortable enough for commuting and will enhance the balance of the car. You’ll notice less body roll and experience a more ‘competent’ feeling ride compared to stock, and at under $300 they’re a great value. Eibach, Vogtland and H&R Suspension all offer Sport Springs for the Fiesta ST, and each has their own pros and cons – you may want to check out all three before making your decision – but H&R’s Sport Springs for Fiesta ST offer a ride on the sportier side, whereas an Eibach Pro-Kit for Fiesta ST will ride closer to stock.


If you’re more track focused, or are a power-user that prefers to have a full range of adjustments over their suspension, a Coil-Over Suspension setup is the way to go. Experience says that Bilstein PSS Coilovers for Fiesta ST are fantastic, but the H&R Street Performance Coilovers for Fiesta ST are comparable, while BC Racing BR-Series Coilovers for Fiesta ST or Vogtland Coilovers for Fiesta ST are great options for the more budget conscious.

5. Sway Bars

To start, “Sway bars“, “anti-roll bars” and “anti-sway bars” are all the same thing, sort of like how “color” and “colour” mean the same thing. Sway bars are among the best things you can do for your car as far as bang-for-the-buck performance is concerned. The Sway Bars help reduce body roll during fast cornering or over irregularities in the surface of the road. Aftermarket sway bars also typically include new sway bar mount bushings to ensure that overly-soft OEM bushings do not interfere with the new sway bar. While the Fiesta ST’s Suspension handles great from the factory, upgrading it with a set of Eibach Sway Bars for Fiesta ST will help make the balance of the car more neutral and reduce body roll and dial out some of the understeer.

6. Breathe Freely with a Downpipe & Exhaust

When it comes to breathing, most people are quick to jump to Intake – but the trick is, very little is on the market at the moment. Injen and Cobb both have high-flow intake systems in development for the Fiesta ST that should be released some time in Spring 2014- there’s not much currently available to enhance induction beyond Cobb’s Drop-In High-Flow Filter, in the mean time, however, the OEM airbox is only a marginal restriction- so for now, we’ll focus on the other side of the equation – the Fiesta ST’s exhaust.

fiesta st catback fiesta st catted downpipe

For even faster spool-up, throttle response and a few definite ponies, a Catless Downpipe (if you live outside Cali) or Catted High Flow Downpipe (for those who prefer cats or just don’t like the smell of unburnt fuel) is the way to go – pair it with a high-flow cat-back exhaust for maximum gains. Milltek’s Race Cat-Back Exhaust for Fiesta ST is compatible with their Catted and Catless High Flow Downpipes, but we also offer a Borla Cat-Back Touring Exhaust and a Magnaflow Cat-Back Fiesta ST Exhaust as alternate options. This is more subjective as to which exhaust is best, as the best one for you will be the best balance of sound and flow – you’ll notice the greatest improvement in performance by upgrading the downpipe AND the exhaust together.

Other Things to Consider…

Front Mount Intercooler
A larger Front Mount Intercooler, such as the one from Forge Motorsport or the one in development from Cobb (available 2014) and several other suppliers, will help the car by lowering the intake air temperature. Hotter air is less dense in oxygen, meaning that it makes less power burning the fuel inside your engine. Cooler air is more dense and therefore richer in oxygen, meaning more power is available. The lower intake air temperature has the added benefit of helping keep your motor cool and the enhanced cooling capacity can allow you to run more aggressive tunes by reducing the risk of knock/detonation. It will also slightly change the tone of your motor. Contact a Modification Expert if you’re interested in a Forge Motorsport Front Mount Intercooler – a FMIC will make more of an improvement in power than an exhaust system if opting for one or the other, and works great as a complement to other modifications.

Rear Motor Mounts
The Focus ST suffered from tons of wheel hop and harshness when shifting, because the ST utilized the same rear motor mount as standard Focus models – which just aren’t up to the torque produced by the EcoBoost motors. Likewise, the Fiesta ST also uses the same motor mounts as the standard 1.6L NA Fiesta, meaning 1-2 shifts under heavy throttle can be harsh and wheelhop can be a problem when going WOT at low speeds. While not yet available from US Suppliers, Cobb has one in development and others may be available as well. The OEM bushing is simply too soft and allows too much engine movement – probably contributing to the torquesteer incurred under heavy throttle on poorer-condition roads.

Limited Slip Differential
One of the areas the car really hurts is its lack of a limited slip – meaning that no matter what, the car is going to one-wheel-peel. This also means that under heavy throttle it’s not going to deliver power evenly – and thus, torque steer. By replacing the OEM open diff with a Limited Slip Differential, such as one from Quaife, the car will torque steer less. While not yet available for US models, one will be available soon, so it’s definitely something to keep in mind, especially after completing the other upgrades listed.

Upgrade The Part Between The Seat And Steering Wheel- The Driver!


No amount of money thrown at parts on the car will make you a better driver. Time and again, Ferrari and Porsche drivers have proven to everyone at track days that buying a Ferrari does not automatically make you capable of driving one at the limit. Getting some seat time in the car and trying it out on a pylon course before you go hitting up Tail of The Dragon, Mulholland Raceway or Glendora Mountain Road is a fantastic idea – and will keep you from being the guy who actually managed to roll a Fiesta ST.

Photo Courtesy MKVIIST,

Photo Courtesy MKVIIST,

By improving yourself as a driver, you’ll be able to go faster around that corner than the guy in the more expensive car, able to brake later and stay on the power longer. As a result of your own improvement as a driver, you’ll be able to get the most out of your car. Try attending an SCCA Solo event or a local track day. These are great, as experienced drivers are often willing to help you out and critique your techinque to help you improve, and hell- as someone who bought a Ford ST vehicle – did you know you automatically are qualified to get professional Driving Instruction at Ford’s ST Octane Academy? Be sure to take advantage of such programs while they exist.

Thanks for reading, and we hope this has given you some insight into upgrading your Fiesta ST in the future. Not sure what to upgrade next, or are unsure of what wheel/tire combo is best or which suspension option is right for you? You can always consult a Modification Expert using Chat at or just calling (714-582-3330).

Want to get in touch with other Fiesta Enthusiasts? Join the Fiesta ST Forum for Fiesta ST news, meets, tech, build threads and more. Check it out here.

Story by Nicholas Gregson
Photos by Nicholas Gregson & Zach (MKVIIST)