Does PE mode affect tuning VE table

[Bill00Form]

When tuning the VE table don't you need to account for the when the pe mode is enabled? I thought all tuning was in reference to stoich (14.63) Just wondered how you determine when pe mode is enabled and do you need apply a factor to your table. Thanks

[Jester]

I use Lambda when logging my BEN, so if PE is active and I am commanding 12.55 and my WB02 is logging 12.55 my lambda in my BEN map will be 1 regardless. You could also filter out PE data from the BEN map. I'm not the best at explaining things by writing them, hope you understand what I am getting at.

[Chevy366]

The old VE tuning you would use 14.7 for all the tuning of the VE so you would put 14.7 in the PE to keep it from influencing the VE while tuning. This is what I do, VE table is right on then when you add PE to the mix it is usually spot on too. I think now with the AutoVE and AutoMAF you don't even bother anymore.

[Jester]

The old VE tuning you would use 14.7 for all the tuning of the VE so you would put 14.7 in the PE to keep it from influencing the VE while tuning. This is what I do, VE table is right on then when you add PE to the mix it is usually spot on too. I think now with the AutoVE and AutoMAF you don't even bother anymore.
Yes that works too but I find it a bit unsafe once getting in to higher rpm and load.

[joecar]

When tuning the VE table don't you need to account for the when the pe mode is enabled? I thought all tuning was in reference to stoich (14.63) Just wondered how you determine when pe mode is enabled and do you need apply a factor to your table. ThanksNo.

The commanded EQR pid (GM.EQIVRATIO) shows the current commanded EQR (e.g. if PE table is commanding EQR 1.175, then that pid will show EQR 1.175).

Same with the AFR pid (but please don't use this pid for tuning).

You don't need to determine when PE activates, and you don't need to adjust for it.


In general, from the active tables, the PCM selects the richest (at the current operating cell) and commands this EQR, and emits this value on the commanded EQR pid.

[joecar]

Setting PE table to stoich (or otherwise preventing PE) is damaging to your engine.

[Chevy366]

I quote from old AutoVE tutorial, page #5 -- Open calibration {B3618} "PE Modifier Based on RPM" Select all cells by clicking in the extreme top-left, gray cell.
If the calibration is displayed as EQ Ratio then enter 1.0 into the Adjust text box and click the [#] button to set all values to 1.0 EQ Ratio.
If calibration is displayed as AFR then enter 14.63 into the Adjust text box and click the [#] button to set all to 14.63 AFR.
If this is incorrect, please advise and have corrected.
Have used this several times and it works without incident.
Theory was and I guess has changed since then, that PE wasn't needed to adjust VE to BEN factor 1.

[picnic_george]

2 different ways of doing things. I've done it with disabling PE/setting companded where I want it, and leaving commanded alone and setting PE where I wanted it. I've not had issues doing either. The point is to get to your VE table correct, and if all your other data is correct(injector) and your actual AFR is the same as your PCM commanded AFR then you're good.

[joecar]

I quote from old AutoVE tutorial, page #5 -- Open calibration {B3618} "PE Modifier Based on RPM" Select all cells by clicking in the extreme top-left, gray cell.
If the calibration is displayed as EQ Ratio then enter 1.0 into the Adjust text box and click the [#] button to set all values to 1.0 EQ Ratio.
If calibration is displayed as AFR then enter 14.63 into the Adjust text box and click the [#] button to set all to 14.63 AFR.
If this is incorrect, please advise and have corrected.
Have used this several times and it works without incident.
Theory was and I guess has changed since then, that PE wasn't needed to adjust VE to BEN factor 1.
Yes, that is incorrect... AutoVE has long since been modified to allow PE mode (whether documented or not).

Works ok if you keep engine load light... but then how do you tune for high load (WOT) or even medium load...?

Theory was that the transition to PE introduced some inaccuracy (wideband being downstream sees the transition after some time delay)... but since the PE transition coincides with throttle transition, the transient filter removes the PE transition.

[Jester]

I quote from old AutoVE tutorial, page #5 -- Open calibration {B3618} "PE Modifier Based on RPM" Select all cells by clicking in the extreme top-left, gray cell.
If the calibration is displayed as EQ Ratio then enter 1.0 into the Adjust text box and click the [#] button to set all values to 1.0 EQ Ratio.
If calibration is displayed as AFR then enter 14.63 into the Adjust text box and click the [#] button to set all to 14.63 AFR.
If this is incorrect, please advise and have corrected.
Have used this several times and it works without incident.
Theory was and I guess has changed since then, that PE wasn't needed to adjust VE to BEN factor 1.
Jeepuz, didn't know that was in a tutorial, nasty.

@Bill00Form - Have we helped or made things worse in your understanding?

[Bill00Form]

No, it's helped and thanks for the help. I have some basic understanding of the theories but I don't know enough about EFI Live pids/data to know if it gets filtered out and when. When you don't use the software in a while you forget a lot too. I would never want to turn off the pe mode especially on a modified/higher compression motor like mine.

I've always had trouble with the maps. Wish they had some basic VE and MAF correction maps setup that you could just select. The dashboard seems very helpful too if it had the correct data. I know it's asking a lot but if someone could do a you tube video on setting up the maps that would be awesome.

It's been a while since I looked at the logs so when I ran at the track a couple weeks ago I was comparing lambda data to the O2 sensors. I wasn't sure if lambda should be 0.88 (commanded PE) or 1.0. The O2s were 876-925 in 4th gear (confirming the .88 is correct) but were reading much higher in lower gears. Lambda seemed to be more consistent than the O2 readings.

[Chevy366]

Yes, that is incorrect... AutoVE has long since been modified to allow PE mode (whether documented or not).

Works ok if you keep engine load light... but then how do you tune for high load (WOT) or even medium load...?

Theory was that the transition to PE introduced some inaccuracy (wideband being downstream sees the transition after some time delay)... but since the PE transition coincides with throttle transition, the transient filter removes the PE transition.
Yeah I know you worked out the Calc. VE and Calc. MAF that PE is not a factor any longer. Thanks for that.
I have not used either one so I was just going by the old way used in 2006. I did WOT pulls with PE disabled and no ill effects. My engine is not stock, while not a super HP one, a mild one would be the best description, now in boost a BIG NO NO. PE is to subjective to consider it correct without a correct VE first.
There use to be in the old tutorial section a video of setting up a filter and such, don't know if it is still there or not.

http://www.efilive.com/documentation-tutorials (http://www.efilive.com/documentation-tutorials)

Please note: Ignore me, joecar is far more knowledgeable than I, I am just showing perhaps where we came from to get to where we are today.

Also note: AutoVE tutorial is the 2006 version still.

[Bill00Form]

Ok, I was looking at the data in my log and I saw that EQR PID for the commanded Lambda. Thanks. It was in terms of 1.15 but my pe is setup so that .88 is equivalent to 12.6 AFR. Can you let me know how to change it back? Also if the map is setup just to duplicate the VE, the table wouldn't account for the pe, right?. Does a separate table need to be setup like the VE table that just populates with the EQR value and these amounts applied to the first table to get back to the 1.0 PE ratio? I assume the same thing would be needed for the MAF table? Sorry if this has already been explained somewhere. Thanks

[Bill00Form]

Does the Calculated VE, BEN corrected do the PE adjustment for you? Thanks

[joecar]

Ok, I was looking at the data in my log and I saw that EQR PID for the commanded Lambda. Thanks. It was in terms of 1.15 but my pe is setup so that .88 is equivalent to 12.6 AFR. Can you let me know how to change it back?EQR is defined as 1/Lambda.

So your PE is defined as 0.88 Lambda (in EQR this is 1/0.88 = 1.136)... in the tunetool you can set fueling units to EQR (Edit->Properties->Fueling Units, select EQR, restart tunetool), this will make it easier to correlate between the PE table and the commanded EQR pid (GM.EQIVRATIO).

For gasoline ("E00"), AFR 12.6 is EQR 1.165; for E00, EQR 1.136 (0.88 lambda) is AFR 12.9.


Also if the map is setup just to duplicate the VE, the table wouldn't account for the pe, right?. Does a separate table need to be setup like the VE table that just populates with the EQR value and these amounts applied to the first table to get back to the 1.0 PE ratio? I assume the same thing would be needed for the MAF table? Sorry if this has already been explained somewhere. ThanksYes, the map is a duplicate of the VE table (copy the VE table, then in the map properties click Paste Labels on the Row and Col tabs).

The VE table accounts for airmass (not fuel); when PE enables, the pid GM.EQIVRATIO shows the PE EQR ( the correction factor is GM.EQIVRATIO / wideband_eqr ).

No, just one table, the VE table. Do not set PE to EQR 1.00 (set PE to EQR 1.175 and then leave it).

Yes, same for MAF table.

See Calc.VET thread post #1.

[joecar]

Does the Calculated VE, BEN corrected do the PE adjustment for you? ThanksNo... PE adjustment is not needed...

When PE is active, the commanded EQR pid (GM.EQIVRATIO) shows the PE EQR.

[Chevy366]

Values of percentage of correctness, .98 is 98% , .97 is 97%, in the BEN, 1.00 is 100% of targeted value, as the other way, 1.10 is .10 over 100% BEN. Although values do indicate richer, leaner but not the goal, 1 or 100% BEN is.
Achieving BEN values with PE means when/if you change the PE value the VE BEN value will need to change too and need to be adjusted to compensate for it.