It’s been a little while since I’ve written about my Ford Fiesta ST. If you’re not really familiar with the platform, read Jalopnik’s awesome review. The last time we talked about my Fiesta ST was probably early in the summer. Well, someone rear ended me (talk about luck!), and it went away for a little bit. But this time was far shorter than before. In any case, I decided to add some new parts to the car. In my boredom, I figured I needed to start feeding the modding bug a little now that we had a feel for the car. So, what did we do?
First order of business was to replace some tires. I opted for some Dunlop Direzza Sport Z2 Star Spec (Dunlop’s evolution Z2 200tw autocross/extreme summer tire) in 205/50/15 over my lightweight Sparco Assetto Gara wheels. That would give me maximum grip, at the expense of a little bit of wet traction. Direzzas are known for their sublime steering feel, and I decided that combined with the FiST’s already nice steering would be just what we needed for the car. I picked these up for a bargain directly from TireRack at one of their distribution centers. If that option is convenient for you (their northeast DC is only 40 minutes’ drive for me), I highly recommend it.
Following that theme, trying to improve traction for hard launches and increasing front end grip required another part: a more robust rear motor mount. I chose one from Mountune USA. They’ve a storied history of making parts for fast Fords, and as many of you may know, they’re the outfit that’s massaged my ECU. More on that later. Here’s the urethane mount and bracket, unboxed:
As you can see, it’s a fairly pretty piece, almost too pretty to go underneath the car. Getting this on the car was a pretty easy process too. Together with an extra set of hands (my lovely and talented pal Amy from StripesRacing; she’s used to wrenching on Subarus, namely her 2005 WRX STi racecar), we put that on in short order. It was the downpipe we had more trouble with.
But first, let’s talk about that downpipe.
I elected to go catless for a little more growl and extra returns. This one is a very nicely welded example from ATP Turbo out of California, three inches with a four inch flex section, and a necked down exhaust flange. I took some time to wrap it up in heat wrap to keep those engine bay temperatures low, and exhaust gas velocity high. This particular wrapping (from DEI) didn’t require any spray-on treatment or soaking.
I could probably have done a better job.
Satisfactory for my own handiwork, I guess. Someone suggested afterwards that I might want to use hose clamps to secure the exhaust wrap rather than heat-resistant metal cable ties but, I feel these will hold just as well, even if they were a little harder to manipulate. Lesson learned. Itchy stuff though, so I made sure to wear long sleeves and use gloves.
I also purchased a Turbosmart Kompact series Dual Port blow-off valve (not pictured), and with my parts in order, and a base map from the talented Randy Robles at Mountune USA, we were set to slap on all the parts. Unfortunately, we ran out of time after getting some heat shields off and settled for getting the engine mount done. The end of a long day reorganizing the garage and wrenching was a chill hangout with Amy, Dawn, and Hosen, who showed up in his AE86 which you are by now, quite familiar with. We reassessed our plan of attack over some pizza, delivered by an AE86.
Hosen, who speaks a little bit of Japanese (he’s originally from Hong Kong though), said to me upon exiting his hachiroku, “Sorry, I don’t have any tofu this time,” and handed us a pie.
What’s that in front of the FiST? Why, that’s Amy’s EFI Logics / JNA Performance Parts / Ruge’s Subaru-sponsored GD STi racecar. You’ll see more of that. We decided I would make an appointment with EFI to get the rest of it installed; I was two hours from home in upstate New York, and Amy had SCCA SOLO Nationals coming up in a few days, so there was no time for a second attempt.
For the uninitiated to Subaru and various other platforms, EFI is one of the top tuners in the Eastern US. They’ve made an almost cultish following out of thousands of Subaru owners and run their own privateer racecars at track events throughout the northeast. Astute youtube viewers may remember them from Larry Kosilla’s brief visit to them so he could borrow their dyno for his 964. Many of my friends—not just Amy—have had plenty of work done there, so they were my first stop.
A couple weeks later, I was at EFI, giving them my keys, and they got to work. After a little bit of Archer Vice in their very awesome chillout waiting room, Amy turned up to hang out and keep us company—as well as oogle Joel’s new auction-bought Miata racecar. They, along with Amy, were to run that weekend at the recently refurbished and repaved Palmer Motorsports Park in Massachusetts.
While we spent time talking shop and doing our thing, the boys at EFI did their thing, and got the parts slapped on, and everything put back together in short order, and handed me back my car, now with more boost-y noises and more rorty exhaust sounds. Also the sweet, sweet smell of catless exhaust and fuel. The smell...of performance!
The only thing left was to flash my new base tune on, and then get some data to my tuner, Randy at Mountune. That took a little bit more time and several proving sessions. The weather cooled off significantly in that time, requiring us to make adjustments here and there (and pause while we waited for a new OBD-II cable after mine shorted out). Eventually, after sorting out an issue or two, we got to a point we were pretty happy with, unlocking more power and even more torque from the little EcoBoost.
I’d say that’s a nice, healthy torque curve, and the 222whp isn’t too shabby either. The tune’s been running just a hair under 24 pounds of boost and an air fuel ratio very close to 12:1. What can I say about how it feels? Now with the the added power and torque, as well as the extra grip, the car feels fully refreshed. Third and fourth gear are especially sprightly; the car practically leaps forward with a touch of the throttle in both those gears. The powerband feels big and meaty in the middle, and you hardly notice the very small KP39 turbocharger’s fall-off toward the end.
Originally I thought about also adding a Turbosmart IWG75 uprated wastegate actuator with a heavier spring to combat this slight power fall off at the top end, but Randy advised against it, citing how it wasn’t necessary, and wouldn’t really be worth the risk.
It was time for the best proving ground: The mountains.
We headed deep into the Berkshires, my old stomping grounds, to traverse familiar roads and forgotten mountain passes that awaited with sharp elevation changes and tight corners, hefty straights and challenging changes in direction and surface conditions.
The touge is a great tool to reveal the character of a car. Here in these backroads lies real driving joy, and an opportunity to discover how your car is feeling, how it’s reacting, to a bunch of different situations, inputs, and conditions. Never mind that; it was also gorgeous in late October.
And very cold. Temperatures near the peak of the mountain hovered above freezing, and barely in the mid-40s at the base. Hardly the best weather to test out some 200-treadwear, weapons-grade autocross/extreme summer tires, but the grip was there once heat got into them. And the turbo kept chuffing along, urging the car onward. Every time the gas was let off, a fluting trill of blow-off signified boost leaving the system through the Turbosmart unit. It startled quite a few people that day.
We also discovered—or rather, re-confirmed—that we definitely need to replace that tiny, wafer-thin factory front-mount intercooler for something a little more considerable. That’s one of the next things on the list. All the power we’re making is nothing doing if we can’t make that power consistently by keeping charge temps low.
In the relative peace of rural New England, I contemplated the offseason coming to us. Drift season would be over in a week or two (in fact, Club Loose Stuffed Moves is this weekend, and though there’ll be a December, two-day event, I’m not sure I’ll brave the below-freezing temps during the holiday season for that). It’ll be an opportunity to evaluate what I need to do next, what direction I’d like to take with the little monster.
Until then, I have a freshly retuned car to enjoy, or at least enjoy as much as I can until I need to mount up some studded winter tires and take it easy for a few months during New England’s brutal winter. But maybe once the snow starts to thaw, there’ll be new parts in my garage, and I’ll be contacting Randy again for some changes to my tune...
(My name is Kay Inoue. I’m a self-taught automotive photographer in the US Northeast covering drift, stance, motorsports, and car culture in the New England and New York Tri-State area. Follow me on Instagram @inoue.kay ).