Colder spark plugs

Discussion in 'Fiesta ST Maintenance' started by RDgolfer, Nov 15, 2014.

  1. Randy@mountune

    Randy@mountune Active Member

    It's not anything out of the ordinary to have some knock activity. The sensors are very sensitive. If you monitor even the stock program you will see quite a bit of correction. What we want to see if the EXACT nature of the correction and under what circumstances. This is why my data logging list and guidelines are so important. If you deviate from this the results can be less than desired. So, again, you need to be data logging Ign Corr Cylinders 1, 2, 3, and 4 along with everything else on my list. And for monitoring I watch: AFR, Boost, and Ign Corr Cyl 1-4.
     
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  3. RDgolfer

    RDgolfer Active Member

    So it got me wondering...and I don't know a thing, but is the Stoichiometric rating increased during hard acceleration? Ie, when I get on it, will the fuel/air ratio become more rich so as to cool the combustion chamber, hence reduce knocking? I understand your thoughts on an overly sensitive knock sensor, but when I do get on it, I think I can hear something...it may be due to this being my first DI power plant...just fishing
     
  4. Dyn085

    Dyn085 Active Member

    Stoic AFR is not used in hard acceleration.
     
  5. RDgolfer

    RDgolfer Active Member

    Ok....does that mean the fuel/air ratio is not made to be more rich under hard acceleration by a tuner?
     
  6. RDgolfer

    RDgolfer Active Member

    I was reading that the fuel/air ratio could/should be as low as 11.3-12. something under hard acceleration to keep the combustion chamber cool enough with the extra fuel, less air to keep knock from occurring...
     
  7. RDgolfer

    RDgolfer Active Member

    Ok, can the Stoichiometric rating be manipulated in a tune to advance or retard depending on throttle position? Ahh....there it is...and sorry for calling you an idiot Dyno...lol
     
  8. Randy@mountune

    Randy@mountune Active Member

    You run the stoich setting in closed loop for idle and cruising at about 14.08:1 and this is how it comes from the factory. It's typically 14.64:1, but with the 10% ethanol being a factor in the majority of markets, it's set to 14.08:1 to be safe from Ford. We stick to that in our programming, too. The target AFR will stay at that value until you reach certain criteria, such as throttle position, load, and coolant temps. And at WOT you will see a richer AFR since that is needed. In the earlier RPMs at WOT you may not be a ton richer, but as the RPMs increase you will see more fuel being targeted and delivered.

    The aforementioned is for standard petrol, I should add.
     
  9. RDgolfer

    RDgolfer Active Member

    And you program the richer air/fuel mix going towards wot with the pedal position, yes?
     
  10. RDgolfer

    RDgolfer Active Member

    I may have said that somewhat askew
     
  11. RDgolfer

    RDgolfer Active Member

    Yes, I re-read your post, and now I see the light...richer when needed, and not at idle or low rpm's...that is exactly what I was looking for, even though I may have glossed over it originally...my bad...and thanks...you will receive more noobile stuff in the near future
     

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