PE hit while tuning VE

[ryanh1986]

Using the guide on the HPT website (https://www.hptuners.com/help/vcm_ed...to_user_sd.htm)

It makes no mention really of not hitting PE while tuning the VE table. I've been pondering about that and the fact that PE will come on in the higher cells anyway... but the AFR error % changes along with the PE hit, so the cell number should theoretically be pretty close no matter what, right? Is this not acceptable? I can't seem to get any of the higher cells after 3,200 RPM no matter how hard I try if I'm avoiding that 50% throttle mark.

[Torque_Vector]

Well. Something to think about is, if you go into the Editor and look for Power Enrichment setting you should be able to set it so that PE is not Enabled. By changing the setting (PE Enable MAP: 640 KPa) which says if the MAP sensor has to exceed this value in order for PE to be Enabled if it does not exceed the value then PE will NOT be Enabled.

You should be able to verify this in the Scanner by scanning commanded (lambda or AFR) and seeing that the cells should be 1.00 lambda or ~14.7 until you hit PE. Scan before and after you adjust the PE setting to verify that you are not entering PE. Remember the PE table is in Equivalence Ratio so if in your desired PE table you have 1.164(or whatever you have) that should read 1/1.164=.859 Lambda or .859*14.7(the 14.7 value is whatever you have set as the stoich afr in the editor)=12.628 AFR

Hope that helps. I am still new to all this so if I have anything wrong please feel free to correct me if I'm wrong anyone.

[ryanh1986]

Well. Something to think about is, if you go into the Editor and look for Power Enrichment setting you should be able to set it so that PE is not Enabled. By changing the setting (PE Enable MAP: 640 KPa) which says if the MAP sensor has to exceed this value in order for PE to be Enabled if it does not exceed the value then PE will NOT be Enabled.

You should be able to verify this in the Scanner by scanning commanded (lambda or AFR) and seeing that the cells should be 1.00 lambda or ~14.7 until you hit PE. Scan before and after you adjust the PE setting to verify that you are not entering PE. Remember the PE table is in Equivalence Ratio so if in your desired PE table you have 1.164(or whatever you have) that should read 1/1.164=.859 Lambda or .859*14.7(the 14.7 value is whatever you have set as the stoich afr in the editor)=12.628 AFR

Hope that helps. I am still new to all this so if I have anything wrong please feel free to correct me if I'm wrong anyone.

If you'll notice in the guide I posted above, PE is specifically enabled and also set to a desired enrichment ratio on purpose. So my question is "Am I to assume it's safe to hit PE using this guide, and this guide alone?" AKA have I missed anything? Should I be filtering out the PE hit, or not? It makes some sense to me that filtering the PE hit using this guide isn't completely necessary, as the commanded AFR vs AFR error % will change when backing out of the throttle.

[dermotw]

Hi, yes, the commanded AFR will change, but many like to do it with the setup 'flat' i.e. no PE, on the assumption (I think...) that removing as many variables as possible helps accuracy. Myself I have done it both ways and these days I leave the PE on, but thats just me...

[Torque_Vector]

If you'll notice in the guide I posted above, PE is specifically enabled and also set to a desired enrichment ratio on purpose. So my question is "Am I to assume it's safe to hit PE using this guide, and this guide alone?" AKA have I missed anything? Should I be filtering out the PE hit, or not? It makes some sense to me that filtering the PE hit using this guide isn't completely necessary, as the commanded AFR vs AFR error % will change when backing out of the throttle.

Yes, I would agree that it would be ok to not filter PE since AFR commanded will change in your error formula accordingly. The more different numbers you incorporate in the error equation such as different commanded AFR's could make the data not as accurate as dermotw said. If you filtered it out then you wouldn't get any data in the PE range and if you are tuning the VE you want to get into as much range as you can before tuning the PE. So the only way would be to remove PE while tuning the VE (if you choose to) or just do it the way the guide says and leave it. I think it would be ok to just go ahead and leave PE enabled.