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WOT's Up Doc?
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Discussion Starter #1
Has anyone successfully calibrated an 04 MAF?

I have heard that you don't want to touch the WOT range. Is this true?
 

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WOT's Up Doc?
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Right. I just found a very good write up on it. It appears you need to consider your PE settings. As they will kick in at a specified RPM. At that point the PE settings override the MAF. So any MAF settings above the PE kick in aren't used.

Unless I misunerstood?
 

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GotTogO said:
Right. I just found a very good write up on it. It appears you need to consider your PE settings. As they will kick in at a specified RPM. At that point the PE settings override the MAF. So any MAF settings above the PE kick in aren't used.

Unless I misunerstood?
Here's where things get easy for the lazy... when tuning WOT you can manipulate the PE table to achieve the desired A/F ratio without ever having to touch the MAF curve. This is NOT the proper way to do things. The proper way is to set your PE table to the desired A/F ratio then re-calibrate the MAF curve until the WB AFR matches the PE AFR.

If you do the proper calibrations you will then be able to adjust your PE table and still be close to the desired AFR even if you do not have a wideband sensor installed.

Tim
 

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WOT's Up Doc?
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Discussion Starter #5
I see. And that may be what the writeup actually said. I'll need to double check when I get home.

Thanks!
 

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Tim05...Off topic but wondering how you deal with the issue of auto trans pressure going max when failing the MAF on the LS2's. HPT 2.1.12 can do it but not sure how.

Sorry for the hijack...
 

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Tim05GTO said:
Here's where things get easy for the lazy... when tuning WOT you can manipulate the PE table to achieve the desired A/F ratio without ever having to touch the MAF curve. This is NOT the proper way to do things. The proper way is to set your PE table to the desired A/F ratio then re-calibrate the MAF curve until the WB AFR matches the PE AFR.

If you do the proper calibrations you will then be able to adjust your PE table and still be close to the desired AFR even if you do not have a wideband sensor installed.

Tim
This confused the hell out of me.
you can manipulate the PE table to achieve the desired A/F ratio & This is NOT the proper way to do things.
followed by
The proper way is to set your PE table to the desired A/F ratio

Whats your take on the actual order to do this then (assuming you have a WB)? Is it:

goto SD mode, turn off the MAF , turn off PE
do your normal VE/SD tuning (avoid WOT)
while still in SD mode, turn on PE, tune PE to desired final AFR in WOT mode using the WB
*then* log and calibrate your MAF?

Or are you saying something different.
I am sorry, I just am having a hardtime understand the order in which you are suggesting to do things.

Thanks.
 

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Sorry for the confusion... If you have done all of this before then my post would not be confusing but to others it may be.

Here is what I consider the proper flow... I don't think I will have anyone disagreeing but you never know :)

- disable closed loop mode, disable MAF (you will now be in open-loop SD mode, don't forget to clear your LTrims)
- set PE table to desired F/A ratios
- recalibrate VE
- enable MAF (you will now be in open loop mode)
- recalibrate MAF curve
- re-enable closed loop mode
- generate histogram of LTrim vs. MAF Hz.
- tweak MAF curve as needed if the LTrims are skewed too far... if there is skew it will usually be in the idle or very light throttle ranges. Your WB and factory O2 sensors may not agree exactly on what is 14.7:1 and this will show up in the LTrims.

This is the rough outline. Extreme combinations (turbos, etc.) may need some intermediate steps to ensure a safe AFR throughout the process but that is not the norm for most.

Tim

Steel Chicken said:
This confused the hell out of me.
you can manipulate the PE table to achieve the desired A/F ratio & This is NOT the proper way to do things.
followed by
The proper way is to set your PE table to the desired A/F ratio

Whats your take on the actual order to do this then (assuming you have a WB)? Is it:

goto SD mode, turn off the MAF , turn off PE
do your normal VE/SD tuning (avoid WOT)
while still in SD mode, turn on PE, tune PE to desired final AFR in WOT mode using the WB
*then* log and calibrate your MAF?

Or are you saying something different.
I am sorry, I just am having a hardtime understand the order in which you are suggesting to do things.

Thanks.
 
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