AutoVE with serial wideband Lc1

[gotabav]

I'm working on and AutoVE tune and would like to use my serial connection to my LC1. I have an idea of what I need to do, but I don't want to guess at it.
The main thing I am having trouble with is setting up the AutoVE MAP. Just so I don't mess it up , which PIDs would someone suggest when doing this as well?
This may have been asked before, but when I searched just the set up to log with the serial input came up. Any help would be greatly appreciated.

[joecar]

Instead of using the pid CALC.BEN_LC11, use the pid CALC.WO2BEN from the calc_pids.txt file attached to post #1 of this thread:

A-New-Twist-on-CALC.-VE-Table..Computing-the-Entire-VE-Table.

(you will have to log GM.EQIVRATIO)

On the map, goto the Data tab and use this pid CALC.WO2BEN as the data.


[ note: also check that B4206 is disabled during AutoVE(OLSD), and that if you're running a COS that B3647 does not contain any EQ 1.0 cells ]

[blindawg]

(you will have to log GM.EQIVRATIO)

Why is that? And what does that pid do?

Thanks,
Branden

[joecar]

Some of us have noted differences between GM.AFR and GM.EQIVRATIO... GM.AFR seems to be "filtered"... and wideband seems to follow GM.EQIVRATIO more closely.

[joecar]

They are related as follows:

GM.AFR = STOICH_AFR / GM.EQIVRATIO

e.g.
EQIVRATIO = 1 indicates stoichiometric
EQIVRATIO = 1.2 indicates 20% more fuel than stoich
EQIVRATIO = 0.9 indicates 10% less fuel than stoich

Also, EQIVRATIO = 1/Lambda

Also, EQIVRATIO is not dependent on stoich AFR like GM.AFR is.

There are a few threads going deeper into the reasons for using EQIVRATIO instead of AFR... I'll have to dig them up, unless you beat me to it

[blindawg]

EQIVRATIO = 1 indicates stoichiometric
EQIVRATIO = 1.2 indicates 20% more fuel than stoich
EQIVRATIO = 0.9 indicates 10% less fuel than stoich

Stoich is the starting AFR before any other multipliers are introduced right?

So the map Made in the AutoVE tutorial shows EQIVRATIO?
And by multiplying the numbers from that Map by the corresponding values in B0101 (Main VE Table) will adjust the predicted Air per Cylinder based on how close the EQIVRATIO is to Stoich?

Correct me if I'm wrong please-
If EQIVRATIO is 1.2, when multiplied by a VE value of say 2, it will raise the predicted Air per Cylinder in order to compensate for the 20% of excess Fuel?

Thanks,
Branden

[joecar]

Stoich AFR is what is trimmed to during CL (Closed Loop).

Also, stoich AFR is set in table B3601, and is used to convert the commanded EQ to cylinder fuelmass (grams).

But think of Stoich as being relevant only during CL.

In OL (Open Loop) commanded EQ is obtained from B3605.


The map made in the AutoVE tutorial is of BEN...

BEN is defined as the ratio of commanded fuel to wideband measured fuel...

BEN = GM.EQIVATIO / EXT.WO2EQR1 = GM.EQIVRATIO * EXT.WO2LAM1

i.e. it is a multiplier which when multiplied into the air source table (VE or MAF) it corrects that table.

[blindawg]

And the lightbulb goes on. Haha.

Thanks for the help Joe,
Branden

[joecar]

...
If EQIVRATIO is 1.2, when multiplied by a VE value of say 2, it will raise the predicted Air per Cylinder in order to compensate for the 20% of excess Fuel?
...

The commanded EQR (EQIVRATIO) is not used in isolation... it has to be compared to the wideband measured EQR...

continuing your example:

if commanded EQR is 1.2, and wideband EQR is say 1.1 then the BEN is 1.2/1.1 = 1.0909...

[ keep in mind that LAM = 1 / EQR, so EQR 1.1 equals LAM 0.909; i.e. dividing by EQR is same as multiplying by LAM ]

this means that to make the wideband EQR to match the commanded EQR (this is the "aim"), the airmass source (VE in this case) has to be multiplied by 1.0909... i.e. the VE table is corrected by increasing it by 9.09%.

So if VE was 2.0000 g*K/kPa (which caused the wideband EQR to be less than the commanded EQR), the new/corrected VE is 2*1.0909 = 2.1818 g*K/kPa...

if you now log again with the new/corrected VE, the BEN will now be 1.0.

[mr.prick]

An EQ BEN is not pre-loaded with the latest software?