Fiesta ST Mod Order: What to Do First, What Can Wait, and What to Skip
Most Fiesta ST builds start the same way. Somebody buys an intake because it's the first thing that shows up in a search, then wonders why the car feels exactly the same. The FiST is one of the most fun cars Ford ever sold here, but it's a 10 year old turbo car now, and the order you mod it in matters more than which logo is on the box.
This guide is for the US car only: 2014 to 2019, 1.6L EcoBoost, six speed manual. Not the Mk8 three cylinder, not the old ST150. Every price below is what we actually list it for, and where we don't sell something you need, we'll still tell you.
Each part below is tagged so you can skim:
Step 0: Health Check Before You Buy Anything
Boring, free, and it's the step that saves engines.
Run your VIN for recalls
- Recall 17V-209 (Ford 17S09) names the 2014 and 2015 Fiesta ST. If the 1.6 runs low on coolant, the cylinder head can overheat, crack and leak oil, and that oil can start a fire. The fix is a coolant level sensor and software from the dealer. If you have a 2014 or 2015, make sure it's been done.
- The Fiesta also had door latch recalls in several waves, plus early fuel pump and fuel tank recalls. Put your VIN into the NHTSA recall lookup and get anything open done for free.
- Check your coolant level and look for leaks before you add boost. Low coolant is the documented way these engines die, and a tune adds heat.
Cheap stuff owners swear by
- Fresh gearbox fluid. If 1st to 2nd grinds, change the fluid before you blame the synchros. Owners report a real difference from fresh Ford fluid alone.
- Plugs. Tuned owners mostly run factory heat range Motorcraft SP532 gapped to about 0.026 in. Colder plugs fouled for people who drive a lot of short trips.
- Boost leak test. On a car this age, test the charge pipes and clamps before you pay for a tune. One loose clamp can eat a whole dyno day.
Step 1: Rear Motor Mount
The stock rear (torque) mount lets the engine rock, which shows up as wheel hop, a sloppy shift and the engine tapping the firewall. A stiffer one is the classic first mod for a reason. The honest tradeoff: every one of these adds some vibration at idle, and it's more noticeable with the A/C on. Softer number means less buzz.
Torque Solution Billet Rear Engine Mount
- Billet 6061-T6 aluminum with a single 75A bushing, on the soft side, so it's one of the easiest to live with every day.
- Fits 2014 and up Fiesta ST. Small stock on this one, so don't wait on it.
- $149.99
Damond Motorsports Fiesta ST Rear Motor Mount
- Cheapest one we sell. Damond lists 80A/95A and 70A/90A bushing options, so ask us which one fits how you drive.
- Want to go further later? Damond also does the transmission, passenger side and full mount sets. Those add a lot more vibration, so they're for people who want it to feel like a race car and don't mind it buzzing like one.
- $140 rear mount, $615 full set
COBB Rear Motor Mount
- Two bushings, 68A and 85A. COBB used it on their own Stage 1 project car.
- Owner reviews say smoother shifts but more idle and A/C vibration, and one owner said it didn't fix gear clunk. Honest reviews, honest part.
- $195
Boomba Racing Fiesta ST Motor Mount
- 80A bushing, fits the 2014 to 2019 car. Middle of the road on stiffness.
- $224
While you're in there: shift feel
Boomba Shifter Bushings and Short Throw Shifter
- Shifter bushings are the best value shift upgrade on this car. Start there.
- The short shifter is 10% or 25% shorter on its own, up to 40% with the transmission adapter (that's the Ultimate Shift Package). One owner ran short shifters for 50K miles with no trans problems, so the 'it kills synchros' thing isn't backed up.
- Heads up: a couple of reviewers had to grind the reverse lockout to reach 1st with certain knobs.
- $40 bushings, $340 shifter, $506.35 full package
Step 2: The Tune (It's a Torque Mod)
Here's the thing nobody puts on the Instagram post: on the stock turbo, the tune adds a ton of torque and not much peak horsepower. COBB's own map notes say Stage 1 is about +2% peak hp and +19 to 21% peak torque. That still completely changes how the car drives, because you feel torque every time you pull out of a corner.
| Stage (91 to 93 octane, stock turbo) | Typical Dynojet result | What it needs |
|---|---|---|
| Stock | 178 to 184 WHP / 211 to 222 lb-ft | Nothing |
| Stage 1 | 184 to 194 WHP / 240 to 254 lb-ft | Accessport plus a COBB panel filter |
| Stage 2 | 196 to 211 WHP / 230 to 272 lb-ft | Plus COBB intake and COBB front mount intercooler |
| Stage 3 (adds downpipe) | 204 to 211 WHP / 296 to 300 lb-ft | Plus a downpipe |
Numbers are from published Dynojet tests (Edmunds, FordMuscle, DSport, Rallyways). Different dynos read very differently, so compare gains on the same dyno, not your buddy's number from another shop.
COBB Accessport V3
- The standard for this car. Off the shelf maps for each stage, gauges, logging, code reading, and it's the base every other mod here assumes.
- Same unit covers the 2013 to 2018 Focus ST if you ever switch cars.
- $665, or the $810 Stage 1 Power Package (that one bundles the Accessport, COBB intake and COBB rear motor mount, so it's the better deal if you want all three)
Filters for Stage 1
- COBB's Stage 1 map is written around the COBB high flow panel filter, so that's the one to run with it.
- The aFe Pro Dry S is a drop in for the stock box and needs no CARB number. Lowest risk intake part you can buy.
- $65 COBB, $76 aFe
Step 3: Cooling Before Intercooler
This is where most build lists get it backwards. The stock intercooler does heat soak badly (one stock car dropped from about 178 WHP to about 149 WHP over three dyno pulls). But on track, owners hit coolant and oil temp limp mode before they hit intake temp problems. The oil is cooled through the coolant, the stock radiator is thin, and that's the same system the recall is about.
And here's the catch: a bigger front mount intercooler sits in front of the radiator. One owner saw oil temps climb to 200F on a casual drive after adding one, until he upgraded the radiator. So if the car sees track days or summer heat, the radiator goes in with the intercooler or before it. Never the intercooler alone.
Mishimoto Performance Aluminum Radiator and Fan Shroud
- Comes with the shroud, built for the 2014 and up Fiesta ST. An owner running a Mishimoto radiator plus an oil cooler stayed out of limp mode in upper 90s heat, where a stock car went into it after 5 or 6 laps.
- $599.95
Koyo 36mm Hyper Core Radiator
- Triple pass, listed for the 2014 to 2019 Fiesta ST, bolts in with the factory fan and shroud.
- $619.80
COBB Front Mount Intercooler Kit
- This is the intercooler COBB's Stage 2 map is built around. It doesn't add much peak power. What it buys you is the same power on the fifth pull as the first.
- $1,070
AIRTEC Stage 1 Intercooler
- 7.5 liter core vs 4.5 stock, and AIRTEC says it's proven to 250 bhp. A lot of intercooler for the money.
- AIRTEC is a UK company and lists this for the 'ST180', which is just the European name for our car. Same car, same engine, so it fits the US 2014 to 2019 Fiesta ST. If you track the car, add a radiator with it.
- $441.57
Step 4: Intake, Downpipe, Exhaust
COBB Intake System
- Mostly here because the Stage 2 map expects it. This car meters air with a MAF sensor, so an intake that changes the MAF housing needs a map that matches. Buying a random intake and keeping the stock tune is how you get a car that runs worse.
- No independent dyno isolates an intake on this car. Anyone promising you 15 hp from an intake alone is guessing.
- $435
Downpipe and Cat-Back
- The downpipe is the exhaust part that actually matters for power (that's Stage 3). Both O2 sensors live on it, so a catted downpipe can still set a P0420. Owners chase it with O2 spacers and it doesn't always work. Catless downpipes aren't emissions legal in the US, period.
- A cat-back is sound only. It can't set a check engine light since the sensors are upstream. The Mishimoto 2.5 in stainless system is the one we carry, and there's a resonated version if you hate drone.
- We don't list a Fiesta ST downpipe right now. Message us and we'll get you the right one for your state.
- $893.95 Mishimoto cat-back, $993.95 resonated
Oil Catch Can
- Keeps oil vapor out of the intake and intercooler, and Mishimoto's testing found most of the oil comes from the PCV side on this engine. Worth it on a direct injected car.
- Honest part: nobody has data on how much a can cuts valve carbon. It helps, but don't expect it to mean you never need a walnut blast.
- The Damond kit is made for left hand drive cars, so it's built for ours.
- $210 Damond, $332 Boomba Stage 1
Chassis: Tires First, Lowering Later
The 2022 Tire Rack SCCA H-Street National Tour champion Fiesta ST ran stock springs. Their biggest changes were tires (Yokohama A052, picked over RE-71R and RT660 after testing), a 25mm front bar with adjustable end links, and as much front camber as they could get. That tells you where the speed is on this car.
Stock it runs 205/40R17 on a 17x7. Owners run 215/40R17 on the stock wheel with no rubbing. We don't sell tires, so spend that money with your local shop first. Autocrossers: lowering springs and a bigger rear bar both bump you out of H-Street, so pick your class before you buy.
Whiteline 22mm Rear Sway Bar
- The cheapest way to cut understeer on a nose heavy front driver. Bolts on, no ride penalty you'll notice on the street.
- The Eibach 21mm is the other common one (it's the bar COBB sells too).
- $255.49 Whiteline, $269 Eibach
Brakes in the right order
- Order goes: high temp fluid, pads that match how you use the car, stainless lines, then cooling. Owners say stock brakes handle autocross and the odd track day once fluid and pads are sorted.
- Hawk HP+ is a street and autocross pad. For real track sessions you'll want a track compound like DTC-30. Owners saw Hawk HPS street pads run past 1,250F at Sebring, so don't take a street pad to a road course.
- Ducting cut peak front rotor temps by about 250F in one owner's paint test. The Boomba deflectors are the bolt on route.
- $167.39 Hawk HP+, $222.29 Hawk DTC-30, $260.43 Goodridge lines, $196 Boomba deflectors
Springs
- Swift Spec-R: about 1.1 in front and 1.0 in rear drop, linear 3.8 kg/mm both ends. Owners lean toward linear springs on this car.
- Eibach Pro-Kit: progressive, about 0.7 in front and 1.0 in rear. Some owners call progressive springs floaty on aftermarket dampers.
- H&R Sport: progressive, listed for the 2014 to 2018 Fiesta ST.
- Whiteline: about 30mm (1.2 in) drop front and rear, 4.0 kg/mm front and 3.0 kg/mm rear. The budget option.
- Nobody has tested how the stock dampers hold up on lowering springs long term. If you're keeping the car, coilovers are the better spend.
- $397.50 Swift, $395 Eibach, $296.65 H&R, $264.49 Whiteline
Coilovers
- In a 373 vote owner poll, more people planned coilovers than springs. Matched spring and damper beats springs on worn stock struts.
- ST Suspensions is the entry point, KW V1 is the comfortable daily, KW V3 adds adjustable damping for people who actually change settings.
- $989 ST, $1,704 KW V1, $2,574 KW V3
Past 210 WHP: Big Turbo Territory
The stock turbo runs out around 200 to 215 WHP on COBB maps. Past that you're into a new turbo, fuel parts and a custom tune, and it's a different project with a different budget. One documented owner build made 330 WHP on E40 with the stock fuel system, then about 390 to 400 WHP after adding an Xtreme-DI pump, bigger injectors, a new MAP sensor and a Turbosmart actuator. Those are owner numbers, not a promise.
Xtreme-DI High Pressure Fuel Pump
- For big turbo and ethanol builds. You don't need it on a stock turbo Stage 1 to 3 car. Needs tuning changes.
- $699
Turbosmart IWG75 Actuator and Kompact Plumb Back Valve
- The IWG75 is marked race only with no CARB number, and COBB warns against aftermarket actuators on their off the shelf maps. Custom tune only.
- The Kompact plumb back recirculates, which is the safe choice on a MAF car when you're running more boost.
- $190.79 IWG75 (7 or 14 psi), $278.99 Kompact plumb back
Stuff We'd Skip (or at Least Think Twice About)
Throttle body and intake manifold spacers. The claim is 'over 17 lb-ft' with no dyno chart behind it. Maybe. We'd rather you put that money toward a rear mount or tires, where the difference is real.
An intercooler with no radiator on a track car. Covered above, but it's worth saying twice.
Pick By How You Actually Drive
| How you use it | Do this, in this order |
|---|---|
| Daily driver, wants it more fun | Recalls and coolant check, gearbox fluid, Torque Solution rear mount, shifter bushings, Accessport Stage 1, good tires, rear sway bar |
| Autocross (H-Street) | Tires, front bar with adjustable end links, max legal camber, brake fluid and pads. No springs, no rear bar if you want to stay in class |
| Track days | Everything in the daily list, then high temp fluid and track pads, radiator, brake ducts, then intercooler, then coilovers, then an LSD |
| Chasing big numbers | Do the track list first so the car survives it. Then turbo, fuel, clutch, custom tune. Budget for it like a second car |
Not sure where your car is in the list?
Send us your year, what's already done and how you use it, and we'll tell you the next thing to buy, even if it's something we don't sell. Email contact@sbxperformance.com or DM us on Instagram @sbx_performance_llc.
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Thomas, SBX Performance