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Thread: Closed Loop Compensation

  1. #1

    Default Closed Loop Compensation

    I've been datalogging the last couple of days to fine tune my boosted part of my map, and just curious to why my Closed Loop Compensation is telling me -25% fuel when my Target AFR is my actual AFR. Could someone explain why this is the case? Is the computer already pulling that fuel out from my Base Fuel Table, or is it telling me that's how much I have to pull out? Which wouldn't make a whole lot of sense since it's already at my target.
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    Last edited by VermillionFox; 05-31-2020 at 11:19 PM.

  2. #2
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    Default

    Quote Originally Posted by VermillionFox View Post
    Is the computer already pulling that fuel out from my Base Fuel Table...
    Yes, Closed Loop Compensation means the ECU subtracted -25% fuel to achieve the Target A/F Ratio table. What's in the Learn Table at this area?
    See page 26: https://documents.holley.com/techlibrary_199r11760.pdf (Terminator X Installation & Tuning Manual)
    May God's grace bless you in the Lord Jesus Christ.
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  3. #3

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    Quote Originally Posted by Danny Cabral View Post
    ...What's in the Learn Table at this area?
    Probably about 25%, unless that's the limit he has set in the Learned parameters. Andrew
    Contact me for remote Holley EFI tuning.
    IG @projectgattago

  4. #4

    Default

    Quote Originally Posted by Danny Cabral View Post
    Yes, Closed Loop Compensation means the ECU subtracted -25% fuel to achieve the Target A/F Ratio table. What's in the Learn Table at this area?
    See page 26: https://documents.holley.com/techlibrary_199r11760.pdf (Terminator X Installation & Tuning Manual)
    I actually never had the Learn Table enabled. I thought when manually tuning the Base Fuel Table you had to have it turned off, but maybe this was a false post. Another reason I have it turned off because I've been tuning my engine with my cut out open and when Learning is enabled between the dump being open & closed it doesn't really give me an accurate Learn Table value because the dump open demands a lot more fuel. However, I suppose I could tune the dump always open, but on the streets it's kinda illegal in my area. Maybe the best thing to do is a dyno, but I prefer to learn as much as I can on the roads.

  5. #5

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    Quote Originally Posted by andrewb70 View Post
    Probably about 25%, unless that's the limit he has set in the Learn Parameters. Andrew
    I now understand what it does. I had read a post before that the Closed Loop Compensation is the exact amount of fuel to be taken out of the Base Fuel Table. When I have looked at datalogs and it's telling me to take out 20% when my target is already met, it had confused me with that, but now I understand that it's already taken that fuel out to reach the target hence "compensation".

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