Mountune ethanol programming for the Fiesta ST

Discussion in 'Fiesta ST EcoBoost™ Tuning' started by Randy@mountune, May 19, 2014.

  1. razorlab

    razorlab Active Member

    E50 and the HPFP isn't dropping pressure what so ever.

    However I saw no gains from E40 to E50 on the stock turbo, with an all stock FiST.

    Once you up the exhaust flow that might change, but I still think that with the stock turbo, E85 isn't needed. You can reach MBT with E40 no problem.
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  3. sourskittle

    sourskittle Member

    I have a 3" turboback and ported exhaust manifold/turbine, so while I know the stock housing and turbine wheel are still extremely limited, I should have above average exhaust flow. I just need SOMEONES E50 tune for AFR ( looks are razorlab).

    And I'm going to log some eth runs at the track tomorrow...
  4. ryst

    ryst Active Member

    This might be a silly question (since I'm ignorant on most things tuning).

    But if you adjust the target AFR, would it be safe to run E85 with your current E50 tune, assuming the HPFP could keep up with the extra fuel?

    I would love to run an ethanol tune on my car, but I do not want to have to have to figure out how much of each type of fuel is required to hit E50 every time I fill up.
  5. razorlab

    razorlab Active Member

    I'm not sure what the car would do on E85 because I haven't run it that high in the Fiesta yet.

    Honestly, the way the ECU works, and if tuned correctly, a +/- 10% Ethanol sway e30-e40 or e40-e50 wouldn't be a big deal. It's pretty easy to get it fairly close at the pump without much hassle.

    The ECU is way more dynamic than other cars and if you tune it correctly it can *almost* act like a flex fuel ECU as it sits.
    Last edited: Aug 15, 2014
    ryst likes this.
  6. McRib 1s Back

    McRib 1s Back Well-Known Member

    My car is basically "stage 3" with a couple tweaks (Mountune FMIC). I'm running a 3" cat-free DP that dumps into a resonator, but terminates at that hangar. It's very stable since it doesn't protrude beyond that middle hanger. You'd be surprised how quiet this is. At WSIR it was downright weird -- I'd say it was one of the quietest cars in the run group. Anyhow, the turbo really likes the free-flowing exhaust, and you can hear it spooling aggressively just off-idle. Still, I can't wait for a better turbo!

    My car is a very different beast when I run 100 octane. I have not dyno'd the difference, but I'd bet money it's a big measurable difference. Getting some of that same performance on ethanol would be fantastic.

    I'm hoping that E50 replicates that. Speaking of which, I found a photo over at (provided by member "forcefed86") that is interesting. Those are encouraging octane rating numbers, but what you actually get in terms of effective octane depends on what you're mixing with (anything from 87 to 93 petrol). My guess is that this pump is using something better than 87 as the mix.
  7. ryst

    ryst Active Member

    Based on this pic, it looks like it's mixing E85 with 89 octane, which is better than most places, which mix with 87 to get the E20-E50 fuel.
    Randy@mountune likes this.
  8. McRib 1s Back

    McRib 1s Back Well-Known Member

    Yep, that makes sense, but isn't a certainty. Such stations are a new thing for me (and apparently big in our corn-growing Midwest!). This setup appears to be a "blender pump", but that suggests working with two separate storage tanks of E10 and E85. So, it could still be that it's using 89 octane, and that math works out close enough.


    Last edited: Aug 15, 2014
  9. sourskittle

    sourskittle Member

    I read a ton of those dsm forum posts.
    I'd say that E50 is BETTER than 100oct gasoline. 100oct E50 has better knock prevention properties than 100oct gasoline. Sounds odd, but ethanols cooling is a huge factor, essp at a 50/50 mix ratio.

    No doubt at all though, if your using a cobb OTS tune (which has a good amount of power left in it) and you switch to E30 or E50, there is a WhOLe lot left in the tune.
  10. razorlab

    razorlab Active Member

    Yea ignore all the things you "read" about octane ratings of Ethanol. I've been using, tuning, researching and testing Ethanol for over 7 years now from mild street cars to all out race builds with 700hp.

    For power, it tunes like 120 octane leaded gas, if not better, for a fraction of the price and a fraction of the toxicity.
    Firesail and McRib 1s Back like this.
  11. ryst

    ryst Active Member

    Is it because you not only get the octane rating, but extra fuel that cools the charge on top of that?
  12. McRib 1s Back

    McRib 1s Back Well-Known Member

    Fundamentally, I get the advantages -- but I've never dabbled with ethanol (dark side stuff as far most of my friends are concerned!). As normal petrol guys, we hold onto octane rating as a basic way to relate to pre-ignition resistance limits and to have a mental picture of perceived tuning boundaries.

    Between the bump in effective octane rating (I've been careful to say that), and cooling properties, I totally get how this stuff can be a boon for tuning. We know certain cars/ECUs/fuel systems respond better than others (WRX variants, EVOs, and MazdaSpeed6 guys come to mind). As you know, for every proponent, there's someone who has a reason why this is a bad idea. Frankly, I'm open minded about this. I've tuned a lot of cars, but never with alcohol.

    This car is my budget racer. I'd love a cheap source of reliable fuel that allows me to have big power gains! I'm also open to a certain amount of risk. We have a bunch of FiSTs here in various states of tune. Some want fun for the street, but I'm all about life at the track! Let's give it a go!
  13. sourskittle

    sourskittle Member

    Dinner.... Is there anything corn can not do !!? Lol
  14. razorlab

    razorlab Active Member

    We should probably move this discussion out of Randys thread.
  15. sourskittle

    sourskittle Member

  16. sourskittle

    sourskittle Member

    Randy, Razor
    What kind of AFR do you guys look for on E30-E50 ? What is the safe ranges ?

    Everytime I tried to research and find out, I get all this "noise" about Lamba and static and all this blah blah blah... What numbers should I be looking for on my fiesta ST wideband O2 I see and log on the cobb ?
  17. Randy@mountune

    Randy@mountune Active Member

    On the Fiesta ST with E30 and a stoich setting of 12.95 I tend to target 12.35 in the upper RPMs. And a bit leaner in the earlier RPMs.
  18. Randy@mountune

    Randy@mountune Active Member

    Rod's showing one run with 204WHP / 284WTQ and a run with 209WHP / 281WTQ on vdyno in 3rd gear on E30 right now. Max boost at 24psi tapering down to13psi near redline. Still have room to go with spark, but I'm thinking that the car has reached the point in which adding more spark is not doing anything except increasing cylinder pressures.
  19. Randy@mountune

    Randy@mountune Active Member

    That is what I'm saying. ^^^

    Not sure if you have ever sent me a data log for the 100 octane file or not. Data logging for E30 to E85 would REQUIRE data logging so let me know if that's doable for you. :)
  20. sourskittle

    sourskittle Member

    I just wanted to make sure I was good with my 11.6-11.7 AFR on E30 or E45.

    I may go 5gal of e85 to 7 gal of 93 oct and take some logs tonight.
  21. RDgolfer

    RDgolfer Active Member

    This is a great thread and I am going to use all this info to....what is going on here? Laymen's terms would be nice...stoich...isn't that what chickens rub together to make eggs?

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