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2014 Ford Fiesta ST project

44076 Views 126 Replies 27 Participants Last post by  twendt
So I picked up a 2014 Ford Fiesta ST to play with. There are a bunch of reasons I did this so I'll just make a simple numbered list to help explain why.

1. I wanted a small lightweight car again (It's 27XXlbs)
2. I wanted to learn the Ford ECU
3. I wanted to track a small lightweight car
4. I wanted a small lightweight car that got great gas mileage for my commute

That's about it overall for the reasons. With over 20 years of driving Mitsubishis, Subarus and VW's I never ever ever ever thought I would own a Ford....

For some reason the Focus ST never really intrigued me. After reading all the press about the Fiesta ST, it did intrigue me, I went and test drove a bunch and I totally fell in love with the car. It really feels like something special, a Ford engineering baby.

I still own my current Evo, an Evo 10, for now. It's in a different league for sure, but I didn't buy the Fiesta ST to replace the Evo. So enough about that.

This thread will serve as a place to post my findings as I learn the car, the ECU, etc.

I come from a tuning background. I used to tune Mitsubishis professionally, mainly Evos. Most recently a 2005 Evo 8 MR for 10 years that was my personal project, that I tuned and tracked. It had 500hp on E85. I also had a 2010 Mitsubishi Lancer Sportback Ralliart that I also tweaked and tuned to 400hp on E85. As stated above still have my Evo 10, 400hp, also on E85. You can sense what's coming for the Fiesta ST then.

Initial photos, 100% stock minus upgraded wheels/tires.

2014 Ford Fiesta ST
Recaro Package
"Rado" wheel package (painted wheels and brake calipers)

Wheels replaced with Sparco Assetto Gara 17x7 +42 satin black
Tire replaced with Bridgestone Potenza S-04 205/45/17

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So I've been learning the ECU. Using COBB Accessport with Race Tuner software.

It's very complex. Very very, VERY. Still a bunch to learn and figure out but so far the car is making pretty good gains but I think I might have it tapped out 100% stock. Pushing it more than this made it very cranky and inconsistent so I'll probably pull it back a little until I upgrade the FMIC and get some more flow modifications.

91 oct.

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So I'm running the car a little leaner now at cruise and light throttle. From 14.7 to 14.9.

Surprisingly, on my morning commute today, my MPG went from around 29 to 30.5 which is pretty damn good. Should be interesting to see what the full tank averages out to be.
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Bilstein Coilovers showed up today. Currently trunk mounted.

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Put in some E85 on the way home today, now the real fun starts. :)
Welp, this little guy is seriously waking up with Ethanol!

I logged a bit on my commute to work this morning after tweaking the tune a little bit last night. Got the LTFT/STFT back in line and adding some timing. Feels like a proper turbocharged car now. Can't wait to do more tweaking.

Here is a log with a brief 3rd gear WOT to around 5,200 rpm or so:

Good news is the HPFP looks like it's keeping up no problem at E30 level so far.
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LTFT/STFT still in line. Car feels much stronger with Ethanol (not a surprise).

I'll get some power numbers up this weekend.

This little guy loves Ethanol
Ok here is an update with where I am at with E30!

Before I get to the results, I wanted to say that I found that my logging road shows higher VirtualDyno results on one side of the street compared to the other which has a slight decline. So I went back and ran my logs all from one side of the street which was flatter and they all seemed more inline so I am going to be using that side of the street from now on. You will see my "Stage 1 with tweaks" is showing lower numbers now. Honestly I think this is more accurate by how the car felt tuned on 91, vs stock on 91, and also more inline with the curves I have seen from the COBB maps.

Ok... so with that out of the way...

Here is my first rev of the E30 tune vs stock tune. Pretty big gains for such a dinky turbo car and the same boost levels as my 91 octane tune. Remember the car is 100% stock power wise except for the tune.

It was about 15 degrees hotter today compared to the stock and stage 1 tweaks runs. My Charge temps increased 25 degrees over the span of a single pull. Time for an FMIC upgrade!

Here are all three, stock, Stage 1 with tweaks on 91 octane and where I am at currently on E30

I'm going to be tweaking the E30 tune a little bit more before I move to higher Ethanol levels. I think there is a little bit more room up top for ignition timing.

After logging IPW tonight, IDC's are no problem. Going by the Focus ST guys, the HPFP will be the limiting factor on Ethanol, before the injectors. HPFP might not even be a limiting factor for us with our dinky turbo.

Here are IDC's from my car on E30!

3446 RPM
9.06 IPW
26.02% IDC

6290 RPM
6.83 IPW
35.29% IDC

If our stock injectors are the same as the Focus ST, I believe they are 1kcc.
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So you're mixing E10 and E85 at the pump and using ATR to roll your own tunes? Looking for others to test that tune as well? I have ATR, but I have an induction tube and K&N panel filter. Those shouldn't make a huge difference.
It's currently 4 gallons of E85 to the rest of the tank 91 octane.
Here is RPM, Boost, Fuel Rail Pressure.

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Assembled the Bilstein coilovers today to prepare for install. At under $800 on this platform, these seem like an outstanding value for the money!

Looking forward to installing these.

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So are you gonna upgrade the turbo and still try to run e85?
Going to wait to see the offerings coming up. I think the car would be great with more HP than torque, because of traction. The BW turbo that 2J-Racing is developing could be the ticket.

was your coil over a fiesta st specific setup or just fiesta?
It's the same kit as for the normal Fiesta and Mazda 2. The spring rates are approx 100lb stiffer than stock ST spring rates. I wanted something with better dampening and slightly stiffer spring rates.

Spring rates:

275 f
230 r

171 f
143 r
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Ethanol update...

I'm at E45 now, from E30 before.

FRP still hitting commanded pressure at 2200 no problem.
Any chance you'd release your ethanol tune to the community so we could try (at our own risk of course), or are you planning on monetizing it at some point?
That's a great question. I might do something like what I did/do with the Mitsubshi community:

Want to get more miles and better understanding of the ECU first though. Also would need to look into the logistics and legality of it as well.
you wanna rent a dyno. start increasing the ethanol content and doing runs while watching stoic, and pressure (is that what you watch. do they have something like percentage used, sorta like a non DI motor's injector percentage?)
I'm watching all those things. I've been tuning on Ethanol for over 6 years now on a bunch of different cars, setups, situations, etc.

DI has Injector PW (I posted the current PW values earlier in this thread) but what I'm really keeping an eye on is both the HPFP and LPFP duty cycle and pressure to make sure they are keeping up with the increased volume demands.

Stoich (or whatever you set in the target in this ECU) will always be reached up until it runs out of +30/-30 fuel trims on this ECU. I've been tweaking the Global Scaler with each % of Ethanol change as well so they trims don't have to sway too much as Ethanol increases.

As far as you eluding to using a dyno to find MBT, I certainly agree but I'm not currently shooting for anything close to MBT. Currently seeing what % of Ethanol I can get away with the stock fuel system, then I will do the real fine tuning.
I have no update on the car today so I figured I would just post this photo of it in in my garage with some parts ready to be installed:

I kid, that's a Fiesta R5, and it's not mine, nor is the garage.
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Still at E45, here is a snap of a log from this morning. HPFP still keeping up no problem.

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Ok here is where I'm at currently with E45. I think I'm going to leave it like this for a bit and beat on it and log a bunch to make sure every thing is ok. I could probably run more timing out the top but going to keep it where it is for now.

Really happy with the power gains for a 100% stock Fiesta ST with just E45 and tuning. Pretty darn awesome, especially with the dinky turbo it has.

+35whp / +75wtq peak gains

E45 vs E30

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I would have to become a Cobb Protuner (again) to sell Cobb maps for profit and I'm not in this to make money.

I will continue to share my findings for sure. I think there isn't an issue with sharing maps either if people are curious to see them. You would need to have Accesstuner Race though.
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I was trying to think of a phrase to adequately express what I felt when I first saw the pic of razor's garaged said it perfectly!
Make sure you read what I posted below the photo. ;)
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