Mountune ethanol programming for the Fiesta ST

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

  1. Randy@mountune

    Randy@mountune Active Member

    There is a stoichiometric value that you should change in the ECU when using ethanol. That value changes depending on the ethanol content. For E30 the setting should be 12.95 in just about all cases.
     
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  3. sourskittle

    sourskittle Member

    [​IMG]
    Good times :)
     
    ryst and McRib 1s Back like this.
  4. McRib 1s Back

    McRib 1s Back Well-Known Member

    That's great, Randy. Of course I can provide data logs of anything you need. This car rocks on 100 octane, and it would be nice to capture that with a bit of ethanol! :)

    Want to start with E50?

    It's funny, really -- I have been looking for a better way to dump stale fuel from my car and was staring at the inside of the fuel filler cap earlier today. It states 10-15% ethanol is fine. I've seen that there plenty of times, but it really resonated with me today. I suspect many modern cars that don't claim flex fuel capabilities, do not give such guidance. 10% is the limit in most cases. Knowing our car has the right basic fuel system hardware, we're not up against the basic problems others cars might have here. What can go wrong? ;)

    So, why not start in the middle? Cook me an E50 program, and I'll send you the information you need. From there, we'll find the limits. :)
     
  5. McRib 1s Back

    McRib 1s Back Well-Known Member

    Great photo, skittles! Nice composition, too. Seriously, it makes up for the Corn Pop BS earlier. Heh, 93 octane -- you suck. We're stuck with pee water (and ethanol) in our CA pumps! :)
     
  6. McRib 1s Back

    McRib 1s Back Well-Known Member

    Think of it this way -- different fuels have different oxygen requirements. "Stoich" (short nickname), or Stoichiometric ratios are talking about how much oxygen you need to burn your target fuel optimally.

    Gasoline is 14.7 and straight ethanol is 9 (methanol even lower, but would trash your car!). From there, it's just basic math to get the interim ratios for E30, E50, etc. Said plainly, ethanol has more inherent oxygen (needing less from ambient air), so it requires less to achieve the right ratio. It's not all that tough when you know that. Of course, if you do it wrong, you'll kill your engine. No pressure, right? :)
     
    Last edited: Aug 17, 2014
  7. sourskittle

    sourskittle Member

    I posted datalogs in the datalog section :) good clean 4th gear pulls (2)


    Sent from my iPhone using Tapatalk
     
  8. WScottCross

    WScottCross Well-Known Member

    Randy, Last time I asked, the E30 tune was only available to Mountune customers. Has that changed, and if so, how do we go about obtaining this tune? I'd like to try this out. I already have and AccessPort and the ATR software if that matters.
     
  9. HardcoreFiSTing

    HardcoreFiSTing New Member

    So you just mix it in the tank? Seems very inaccurate. What would these cars need to run E85? Bigger pump or injectors?
     
  10. WScottCross

    WScottCross Well-Known Member

    Pretty easy actually. Once you know the ratio (I'm currently running E40), it's easy to figure out how much E85 to put in before topping off with 93 octane. For me, it's exactly 5 gallons of E85 per tank. Just be aware that higher ethanol blends will seriously affect your fuel economy. Yes, E85 is cheaper, but still not cheap enough to offset the lost fuel economy. With the right tune and some bolt-ons, the power is awesome.
     
  11. HardcoreFiSTing

    HardcoreFiSTing New Member


    I understand the method, but it just seems like it would be difficult to be precise enough. I guess if you started with an empty tank you could just use the numbers on the pump though.
     
  12. WestcoastST

    WestcoastST Active Member

    There are programs that can calculate mixtures based on # gallons in the tank and the octane of the remaining gas. The ST has a12.4 gallon tank
     
  13. HardcoreFiSTing

    HardcoreFiSTing New Member

    Yes, I saw where this was posted above. Knowing exactly what remains in the tank would be difficult I'd think, but maybe it doesn't have to be as exact as I'm thinking.

    I'd just hate to pop a motor because I mixed some fuel wrong, especially given how inconsistent E85 can be straight from the pump without any mixing. There are ethanol sensors/gauges that read your fuel's ethanol percentage as you drive and some software even allows your tune to be adjusted based on this, so that's another solution.
     
  14. WestcoastST

    WestcoastST Active Member

    If you are really interested in knowing the percentage of ethanol in your gasoline, you can combine the a small quantity of the gas in your tank, say 8 oz of gasoline, with 2 oz of water in a graduated cylinder. Because of ethanols attraction to water, mixing the two solutions up will result in gas at the top of the graduated cylinder, and water and ethanol at the bottom. Then you can calculate the percentage of alcohol in the gas. See this website for specifics.

    http://footflyer.com/PPGBibleUpdates/Chapter12/fuel/gas-n-ethanol.htm
     
  15. HardcoreFiSTing

    HardcoreFiSTing New Member

    That's science as fuck.

    If I were personally interested in big power from the FiST, I'd just wait until someone figures out how to run it on straight E85. For me, the gains from Boltons and a tune would be plenty, although I do wish the car made a little more top end, even though the torque is nice.
     
    XR650R likes this.
  16. Pedro

    Pedro Active Member

    Hi Randy, have you gone up to E40 yet? or are you staying with the E30 tune? Also I am planning on buying an AP through Mountune and was wondering if the individual tuning you provide also works with the Ethanol blends? Thank you!
     
  17. Randy@mountune

    Randy@mountune Active Member

    Yes, I've programmed many e40 cars. Works fine. :)
     
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  18. RodMoe

    RodMoe Well-Known Member

    Have you done any big turbo upgraded Fiestas yet and if so have you done any of those on E30/E40??
    Happy Holidays btw
     
  19. WScottCross

    WScottCross Well-Known Member

    Yes, Randy did my E40 tune and it's great! So far I'm only stage 1 with a catback, but still putting down 210 whp with Randy's E40 tune.Excellent product with excellent service. Best money I've spent on my car.
     
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