(This is a little bit that I put together on The Fiesta ST Network forum where I’m a moderator. I wrote it last year, but I figure some of you here might be interested to hear how my experience went).
Recently,I had the opportunity to have my Fiesta ST reprogrammed by long time Ford-platform tuner Randy Robles of Mountune’s USA division (who as many of you know, daily drives a Fiesta ST). Excited by the prospect of having a familiar and trusted name in the industry massage the ECU mapping of my already very enjoyable car, we started out with the usual: a Mountune-concocted baseline, over-the-shelf tune that is shipped with each COBB Tuning V3 AccessPort they sell as a COBB dealer as well as their mTuner. The COBB over-the-shelf v102 Stage 1 93 octane programming was already installed, so at this point, I’d sampled both the car stock, as well as with COBB’s OTS mapping.
(If you’re not familiar with Mountune, go have a look through their credentials tuning racecars for touring cars and rally series. Randy in particular tuned Andrew Comrie-Picard’s Fiesta ST 2WD class winning car. Yes, that car.)
[Update: I’ve since sampled COBB’s updated v. 2.00+ maps, which I run when I have a suspicion my fuel quality is not up to snuff in emergencies.]
Though my focus of this review isn’t on the Mountune OTS map (configured for 93 octane), I’ll give some brief thoughts. For one, I think that the changes to the overall map are a little more aggressive, and a little more dialed in on the Mountune file over COBB. I haven’t tried any of the v2xx maps, but at the time, the shift-assist disable was a big hit for me, as it reduced rev-hang up noticeably, allowing for much crisper and quicker downshifts. This helps a lot when you consider that the dual-mass flywheel on the stock clutch blunts both shifts and throttle response. Speaking of, throttle response felt like it was a little sharper, the engine’s resolve to pull me out of a corner honed to a finer point. Another key difference is that the Mountune programming allowed me to specify a 4,000 rpm fuel-cut launch control logic. Let’s just say I discovered why getting a stiffer roll resistor for your engine is a good idea.
Then, Randy asked me for data logs from my AP so that we could go ahead and start making adjustments specific for my car, and to see what could be squeezed out of it. I’d never had a remote-tune over emails done before, yet even so, it was a breeze. Unfortunately, some outside circumstances (a fender bender for which we weren’t at fault)resulted in my fiancee and I being without our FiST for two months. Nonetheless, Randy let me know we could get started once I had the vehicle back in my hands and was ready to collect more data, which at the time, indicated that the Shell V Power I was running was well,less than stellar. And this is where I need to reiterate what kind of a professional Randy is, not just his understanding that I would have to come back to this at some unknown date, but also his specific questions, and specific disclosures about what was being altered in each revision of the tune.
When I did get the car back, we addressed the bad fuel in my car which was hampering our efforts. I switched fuel brands (Exxon-Mobil to the rescue!) and started anew. Once Randy saw my data and knew he could safely dial in more aggressive parameters, the car changed dramatically. I actually laughed aloud when I checked my phone to find one of his emails stating my new fuel was ‘crazy good’: we were on the right track, and things were getting very exciting. A lot of peoples’ first observation when going from stock to COBB’s Stage 1 tune is that the car is much more aggressive in lower gears due to the removal of torque limits; it adds another dimension to the behavior of the car and its character. Well, think of the difference between the programming I was running before, and the tune which was evolving, custom-tailored for my car like another level, another peel of the onion deeper.
The process would go something like this, for the unfamiliar with a remote tune. Randy would email me a .PTM file to try out (and there were several) and I would drive it around a bit, and when the opportunity presented itself, I collected data for each revision with hard acceleration pulls, logging the parameters he needed in order to see what was transpiring in my engine. I’d take perhaps three solid runs, and unload the logs from my AP with the APManager software and send them back to him. We repeated this process a few times. With the fuel situation sorted, each successive revision moved in a forward direction. Conditions were great for collecting data: I had a nice variation of late-summer into early fall weather to work with, and aside from the final session of logging, it never got too cold.
[My little FiST has changed a bit since those days—notice the stickier rubber—Dunlop Direzza ZIIs. all around. Soon to go on are a fresh set of ZII Star Specs for the front.]
The final product I received was a three-slot ECU calibration which transformed the car. All calibrations were made for 93 octane. Allow me to get down to the details. Peak boost is generally around 23psi (I’ve hit a max observed peak of about 23.6 psi, but this owes more to cold temperatures than anything), and my AF/R at wide-open throttle pulls have been about 11.2-11.4 and 12.5 on the lean end. At one point, before calibration was complete, I was nearly maxing out on timing advance; the car liked the fuel that much. In any event, now I’m hovering around a maximum of +1.20 of correction and a nice, happy -1.0 OAR-L. These don’t really speak to the results though…
I haven’t dyno’d the car yet, so I don’t have a sheet I can point to and say, ‘well, this is what I make now on the tune’. And in a way,that would only tell part of the story. I can tell you that from adig, the tires are nearly useless. The torque simply overwhelms the OEM 205-segment Potenzas’ compound. If it’s chilly out, like it has been the last couple of days, launching requires care, even with TCS on. The way the boost kicks in on the standard car is viscerally exaggerated, even from a roll at highway speeds; the pick-up in any gear is much quicker, much harder than you’d expect from a car with aturbo as small as this one. I’m actually somewhat in awe. I want to make note that even with the COBB OTS maps, I never hit nominal boost targets (the closest I got was 19.8 psi). Not once.
So here’s how the car is currently set up. Now that we have map-switching and on-the-fly switching for the FiST, Randy has set meup with three slots. The COBB v20x maps come by default with a performance and a ‘pseudo-economy’ (and from what I understand,trying to put a full-on economy map as a slot isn’t a great idea,which is why I imagine COBB opted for a wastegate-pressure based Eco-slot) second slot. Like I said, I have three. All have flat-foot shifting enabled above 5,000RPM, and a 7,000 RPM redline.
- Slot 1: Performance, normal boost levels for my programming. No launch control. Boost target is nominally 20.5psi with a taper to ~13.5psi by redline, but with the climate here being what it is, I’ve been seeing higher peak boost. As it is with these things, +/- 1-1.5psi margin.
- Slot 2: Performance, normal boost as above. The difference here is the addition of a 4,000 rpm fuel-cut launch control, which is producing somewhere in the range of nearly 8psi of boost from a standstill. 7K RPM redline, FFS as before.
- Slot 3: Cruise, low-boost map, no launch control. Basically a puttering around, grocery-getting map for less power, which will come in handy in low-grip, inclement situations. I don’t need all the boost, all of the time.
Now that I’ve gone over my three slots, here is some food for thought. Paired with the traction control system (Full on TCS, Sport Mode, and Full Off / ESC Disabled), that is nine different ways I can set up the car to drive around for the day. All without so much as touching the AccessPort. That’s useful technology right there. I’m not sure what parameters can be changed down the line, but I imagine there’s potential here. Just imagine if one day, those of us with LSDs installed could maybe dial up or down the amount of Advanced Electronic Torque Vectoring Control (A-eTVC) based on the map? A worthy thought. I don’t know if they’re there yet, or if that’s possible, but with Mountune now in partnership with Quaife to supply us with differentials, it will be interesting to see how matters develop on that front.How easy is this stuff to use? Pretty easy. Hit Cruise cancel, and thentoggle set + or set -, and I can pick from my three maps. Not toohard. No need to pull over and re-flash, no need to stop the car. From here, it’s about testing out just how good this tune is, and I have an appropriate playground for the Fiesta ST, the environment I’ve found this car excels at: mountain pass / canyon driving. Yet, we finished up tuning as the weather in New England starts to go pear-shaped, and one of my last opportunities to tackle a favorite pass got nixed by a dismal spell of weather that wouldn’t have done any justice to the car (but perhaps the driver). However, I’ll still give my impressions on how the car behaves now. I’ll forgo speaking about Slots 1 and 3; this is really about the full roast.For one, I need a new engine mount. The violence of a launch at 4,000 rpm with fuel-cut launch control puts the engine practically in the driver’s lap.
I’m pretty sure that by now, the bushing is turned to dust. With a loud clop, you hear the back of the engine slap the firewall as the car digs out of the hole, scrabbling for grip as the RE050As struggle to put down the frankly insane (for a 1.6L turbo) amount of torque this car generates down low. With the torque target limiters removed, and the additional power and twist from the tune, even with TCS on, you’re popping off the tires. A sport mode or ESC off tune means that without LC and a careful foot, you’re losing a lot in the standstill to 60mph/100kph run to wheel-spin. Modulate the throttle a bit once the car is underway with LC and you can see (what feels to me) like around a low 6, maybe flat 6 second 0-60. At the least, I feel like a flat six second run up to sixty is there in the car now. At this point, the limiting factor is the rubber. With LC engaged, I’m producing close to eight pounds of boost off the line, and that’s just more than a 205-section with this not-so-great-compound can endure as boost pressure climbs. Throw on some better tires, and a stiffer engine mount, and things will be different. A note for a different day.Getting started from a 4th gear roll is also something of a revelation. I’ve had a friend who is more experienced with Supras and other higher-performance engined cars, and even he thinks that the smoothness and relentlessness with which this car wants to go into the triple digits is addictive. The car pulls and doesn’t run out of steam until near red line, as the incy-wincy turbo starts to run out of breath.
But the high end power has never been the story with the FiST; it’s all about that torque curve. Stock, the car feels like it has a dead-spot around 1800, and 3000rpm. No such problems here. Spool is quicker, boost earlier, and response much tighter. And something that helps you legitimately go faster in the twisties is the adjustment of the shift-assist to basically off; now all you’re competing against for a quick bang down through the gears with rev-matched downshifts is the comparatively heavy dual-mass flywheel. The response on changing throttle input is more instant, more visceral, but still clinically accurate. You never feel too frenetic, like you’ve dialed in too many, or two few revs, and are struggling to correct before you transform the synchros into metalized powder.
The fact that there’s such a slab of torque on hand, and so much smoother(and a bit earlier) than stock means you can put the car in third gear through a snaky ribbon of tarmac and never really find yourself out of place on the power-band unless you’re really blitzing it out of the corner. Even as a passenger (which, I tend to do a lot with this car more than I’d like, since I share it with my fiancee, and sometimes let my best friend drive when the mood strikes), you can feel the difference in the character of the power and response. The stock power was always enough to pin you to the seat (surprisingly) but you’re doing so much more of that now, and the way it does it is so undramatic, it’s eerie. A lot of people characterize the FiST as ‘wanting to go fast and misbehave, all of the time.’
Well, I’ve got unfortunate news for those looking to keep points off-license: this exacerbates that quality.Afew conclusions are in order.So is getting custom calibration worth it, even without hard parts on the car? I’d say so.
The difference vs. an over-the-shelf tune is discernible. Is the process that hard? I wouldn’t say so. Working with a professional like Randy from Mountune has been a real pleasure, and I know once new parts come in for me over the winter,I’ll be calling in his expertise to continue to get the maximum(safe) performance out of my car.
It can be scary trusting the sensitive calibration of your car to to someone from afar, who perhaps you haven’t met in person. But Randy made this process easy and stress-free, and the result has been a car given a new attitude. If you’re going from completely stock ECU to a custom tune, then you will notice even more of a difference. What’s on the horizon for me? Probably a free-flowing turbo downpipe, some cooling mods, and suspension. Only time will tell. But I know who will be doing my programming.
If you own a Ford Fiesta ST (or Focus ST) get yourself an AccessPort, and get yourself a custom tune. And if you can, I recommend you get it from Randy at Mountune.