% Value on VE Table

[Ls1Mx5]

Hello, I'm new here, I've tuned successfully on Hondata's Kpro but never on HP Tuners. So far the people on this site have taught me a lot about how it works, as have some people on Ls1Tech and YouTube but I have a question. I've searched but can't find an answer. On the VE 3d table there's a kPa value, an RPM Value, and a % value. What is the percent value a percentage of?

[2xLS1]

Supposedly a % value of the cylinder fill of air. But don't take it as an absolute real number. It's just a number calculated with data derived from other sensors. And other sensors is not even really a good way to describe it. Just think of it as a calculated number of cylinder fill. PCM will use that number to calculate how much fuel to inject at whatever map and rpm for the commanded A/F ratio at that time.

[Bill@HPTuners]

As outlined above, it is expressed in % to make it easier for most to understand. Values from 0-130% are pretty acceptable, if you going much over 130% you might be doing something wrong.

[Ls1Mx5]

That explains a lot, and just to clarify the A/F is commanded by the "Open Loop EQ Ratio" Table correct? If I understand correctly I should set it to 1 across the board and the PE table will enrich the mixture at higher throttle percentages.

[2xLS1]

That depends in if it's running in open loop or closed loop at the time. There are open loop A/F values and a closed loop A/F value (stoich for the fuel you are using). Open loop table is an EQ of the stoich value. And if there is still a MAF then below the High RPM Disable value in the calibration it uses a blend between the MAF and VE for calculated airflow and above that value it used MAF 100%. Stock calibrations usually set that at 4000 rpm, some a little lower. If running without a MAF in Speed Density it will use the VE for the entire RPM range. PE is also an EQ of the stoich. (stoich/EQ)

[Ls1Mx5]

Thanks for the replies, I'm learning. What do you mean by

Open loop table is an EQ of the stoich value

and

PE is also an EQ of the stoich. (stoich/EQ)

What I also still fail to grasp is why you set Open Loop EQ Ratio to 1.00 all across the table. Don't we want richer conditions under higher rpm and throttle operations potentially before the PE kicks in?

[2xLS1]

Thanks for the replies, I'm learning. What do you mean by

Who is saying to set the OL table to 1? You might do that for tuning the VE table to stoich while forcing OL. But you would need to return the cooler temp values in the OL table so it commands richer like a choke would do.


and


What I also still fail to grasp is why you set Open Loop EQ Ratio to 1.00 all across the table. Don't we want richer conditions under higher rpm and throttle operations potentially before the PE kicks in?


If values are richer in the PE table the PCM will use those instead of the OL table. Think of PE as a conditional OL when certain parameters are met like TPS, MAP, RPM Delsy. PE = Power Enrichment

[Ls1Mx5]

Who is saying to set the OL table to 1?)

https://www.hptuners.com/help/vcm_ed...to_user_sd.htm

6. Under Fuel Control-Open & Closed loop open ?Open Loop EQ Ratio? and set it to 1.00 all the way across. This will set all cells to a 14.7:1 air fuel ratio.

I've seen and heard others make this recommendation as well. Why would one tune for that just to return it to richer values later?

[blindsquirrel]

Those help files have not really been updated in... how many decades? Not that the info is wrong, exactly, it's just things have moved on, the editor and scanner can do things now they couldn't do back then, new tricks have been discovered...

[2xLS1]

Again it's only for tuning the VE or MAF to stoich in open loop and not in Power Enrichment. Not for any other reason. There are times other than PE when you don't want to be at stoich also so you wouldn't have the whole table set to 1.