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Use of Main VE Table

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Old Jan 19, 2005 | 09:17 PM
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Default Use of Main VE Table

What does the PCM do with the values stored in the main VE table?

From what I can gather (nutshell version), the PCM takes the value from the Main VE table that correspond with the appropriate kPa/RPM reading, reads the MAF, IAT, and possibly the ECT, calculates a g/cyl figure, opens the injector, fires the spark.
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Old Jan 19, 2005 | 09:30 PM
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Originally Posted by TAQuickness
What does the PCM do with the values stored in the main VE table?

From what I can gather (nutshell version), the PCM takes the value from the Main VE table that correspond with the appropriate kPa/RPM reading, reads the MAF, IAT, and possibly the ECT, calculates a g/cyl figure, opens the injector, fires the spark.
you got it! Now can you guess what that spark does???

Last edited by txhorns281; Jan 19, 2005 at 10:01 PM.
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Old Jan 20, 2005 | 05:29 AM
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Haven't got to that part yet. I got my IFR table set up proper for my injectors, now my LTFT's are way north of 0. I plotted a map of my calculated VE and found the logged data to be ~15% less than the data used in my main VE table. Anyhow, when I get to screwing with the spark tables, I'll post my theories.
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Old Jan 20, 2005 | 10:08 AM
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Originally Posted by TAQuickness
What does the PCM do with the values stored in the main VE table?

From what I can gather (nutshell version), the PCM takes the value from the Main VE table that correspond with the appropriate kPa/RPM reading, reads the MAF, IAT, and possibly the ECT, calculates a g/cyl figure, opens the injector, fires the spark.
I think you're confused. The pcm can calculate g/cyl from the maf and rpm alone. It can also calculate g/cyl from ve, IAT and MAP. The pcm uses both calculations as described in gameover's airmass thread.
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Old Jan 20, 2005 | 01:17 PM
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P Mack - can you post or PM me the link to the airmass thread.
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Old Jan 20, 2005 | 01:44 PM
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Airmass Calculation

This is the original thread on hptuners. It's been posted around here a few times too.

To summarise:
1. High RPM behavior is totally based on MAF
2. Mid RPM behaviour has an allowance on Steady MAP behaviour before it switches to Unsteady MAP
3. Low RPM behaviour (where the bulk of the fuel cells are) is dictated by unsteady MAP behaviour that is still mostly dominated by the MAF input with small tweaking from SD)
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Old Jan 20, 2005 | 02:22 PM
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Originally Posted by TAQuickness
Anyhow, when I get to screwing with the spark tables, I'll post my theories.
My theory is that the spark causes something I call "combustion". I will post more after I verify my theory.
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Old Jan 20, 2005 | 09:59 PM
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Originally Posted by Another_User
My theory is that the spark causes something I call "combustion". I will post more after I verify my theory.
I'd say you are the sharpest knife in the rack.
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Old Jan 20, 2005 | 10:08 PM
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Originally Posted by P Mack
Airmass Calculation

This is the original thread on hptuners. It's been posted around here a few times too.
Thanks for the link.
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