using 14.047 for desired AFR and not 14.63?

[mr.prick]

It probably will.

The WBO2 sees Lambda and if the AFR settings are gas you will see 14.7 or whatever Stoich is for gas on your WBO2 regardless to what is in the tank.
This is why you should change the fuel setting for the fuel you are using or
use Lambda to avoid confusion.

People with WBO2's that cannot display low AFR can use normal gas settings/display
with Ethanol because "Lambda is Lambda regardless of fuel."

This thread is about OS' with a static stoich AFR thus the reason to change {B3601}.
If you don't change this and use Ethanol the PCM will have incorrect VE/MAF values.

[gmh308]

Well how does that work?
Are you saying E0 = 1.00 Lambda and E10 also = 1.00 Lambda

So the Scan Tool (Tech II in my case) will display 14.7 as the target AFR and the wide-band will read 1.00 Lambda on E0.
Then with E10 the Scan Tool will display 14.1 target AFR and the wide-band will read 1.00 Lambda?

I understand that 1.00 Lambda for E10 is 14.1 AFR. Hmm did I state that correctly

Yes in closed loop whether E0 or E100, lambda will = 1.

AFR will change from as you mentioned 14.7 at E0, 14.1 at E10, 9.8 at E85.

Depends which PID you are checking with the Tech II. The EQ Ratio will read 1 when warmed up in both open (mostly...if that is what OL tables are set to for warm run) and closed loop.

If it is a Flex Fuel engine, then the fuel composition % PID will read the % ethanol it either calculates, or is told by the fuel comp sensor.

With that % ethanol, the ECM will then base its open loop + PE fueling and spark on the ethanol look up tables. And set base Inj PW from the AFR/ethanol % table B3671 (E38/E67). And if all the planets line up, WB lambda = 1, and LTFT's = 0.

Maybe techII has a PID that tells where the ECM is on the B3671 table? That would give you the AFR that the ECM is basing all fuel flow calcs on. Though no doubt depends on which OS you are on.

[mr.prick]

GM.E85PCT

[CalEditor]

Stock Calibrations: Flex vs Non Flex




The Stock O2 sensors will switch at about 450 mv and the fuel trims will be close to 0% on both factory calibrations and on the Flex Fuel across the chart.

A add on Wide-Band will display 1.00 Lambda and 14.7 also. Now lambda is not 14.7 Correct?

If I understand this correctly Lambda = AFR/AFR Stoich (Either from the chart or B3601)

A display of 1.00 on a Wide-Band will = the AFR Stoich, but the display on the add on meter of 14.7 doesn't mean 14.7 Correct?

Basically the Wide-Band Gauge is formulated for E0 or 14.7 = 1.00 Lambda and the gauge will always display 14.7 @ 1.00 Lambda even if the AFR is truly 14.1

[mr.prick]

@ Lambda1 the WBO2 will translate AFR to what it is set to for L1.
If L1 setting=14.7 then you will see 14.7 @ stoich which will actually be 14.1
Lambda will eliminate confusion without having to change the AFR setting.
You will also want commanded AFR to match the fuel you are using. {B3601}

Some WBO2's don't have a Lambda to AFR scale
so you will need to do the conversion yourself if
you want AFR to match fuel type.

Stoich AFR*Lambda=AFR
(someone correct me if I am wrong)

[DrkPhx]

Yes in closed loop whether E0 or E100, lambda will = 1.

AFR will change from as you mentioned 14.7 at E0, 14.1 at E10, 9.8 at E85.

Wow. Am I understanding this correctly? You change B3601 to reflect lambda 1.0 instead of stoich and the PCM will calculate the fueling for different fuels based on that? I'm referring to a LS1 PCM. If I'm wrong, please clarify.

[mr.prick]

I could say "read the whole thread" but I won't and save you an hours time.
{B3601} should be set to the AFR stoich point for the fuel you are using.
Changing it will also change all the fueling tables, as they are actually in EQ.
You see them in AFR because the software converts it from EQ to AFR based on
what {B3601} is.

If {B3601}=14.7AFR & PE=1.17EQ
then PE=12.56AFR

If you change {B3601} to 9.7AFR & leave PE@ 1.17EQ
then PE=8.29AFR

Moral of the story is:
{B3601}=stoich for the fuel type (static or flex fuel) &
if using AFR then make sure Lambda1=stoich for the fuel type so
the AFR conversion is right or use Lambda only.

[joecar]

Use/speak/think/breathe in terms of EQ...

[DrkPhx]

Thanks for the cliff notes. I've actually read through the thread. For some reason I misinterpreted the quote above differently.

Like I previously mentioned, I did play around with changing stoich with mixed results. Fuel trims changed of course, but WOT PE remained exactly as previously commanded, though they are set as a AFR value and not lambda or EQ ratio.

I may revisit this again. Winter just officially kicked in here, so the conditions don't allow me to drive the car. Once again, thanks for the info.

[DrkPhx]

Use/speak/think/breathe in terms of EQ...

LOL. I've tuned in lambda since day one, but switched to AFR a couple of months ago.