using 14.047 for desired AFR and not 14.63?

[joecar]

Does anyone have a dbf for something like an 01 Vette and the later flex fuel trucks? Maybe even the dbf for the bin's I posted.

Joecar if I overstepped the boundaries delete this post.

I don't know who would have those...

The worse that could happen is a "no" response.

I don't see any boundaries being overstepped...

[joecar]

AFR is still important for determining injector pulsewidth.

Oh, yes, I agree, that's how the PCM knows how to determine the actual fuelmass required.

The PCM does applies the modifiers in terms of EQR, and then at the last moment applies the stoich AFR to arrive at commanded AFR, which is required for calculating fuelmass, which then determines injector pulsewidth.

[mr.prick]

I still think a FF OS for F/Ybody is a good idea.

[TunasTwins]

Hey guys, I posted this over at the tunercats forum monodax.com also.
I was under the impression that changing the values in the stoich AFRvs % alcohol in fuel table would make NO difference to my vehicle: 2005 4.8L Tahoe NON FLEX FUEL.
The table makes sense if you have an alcohol % sensor. Well I changed the values, up to 12.5% to 14.37 and EFI Live reports the desired AFR as 14.37 MY WOT also reports richer in EFI Live (14.37/1.165).
What I'm asking is why would EQ1=14.37 if I dont have a flex fuel vehicle?
EVERY pump here in Atlanta says may contain up to 10% ethanol so I'm assuming its in 90% of the pumps. Unfortunately this is my wifes truck so I dont have a bung for the WBO2. How much will my reading be skewed when the sensor is 6" in the tail pipe? What about taking out the rear 02 and installing there?
Well I hooked up the WB and have some results. Can someone point me in the right direction with the data I have?
I commanded open loop and reset fuel trims via EFI live scanner(love it!)
Commanding 14.68, at idle WB reads .98L 02's average .560's mv's
Commanding 14.37, at idle WB reads .96L 02's average .560's mv also.

I FINALLY understand (found) the closed loop airflow mode! NOW the rich/lean 02 volts table makes sense. My gut tells me to raise/richen the mv to .550 across the board. Also, it appears to me by changing the value in the % ethanol table, I'm telling the PCM that EQ1=14.37. Is this true?

[mr.prick]

Well I changed the values, up to 12.5% to 14.37 and EFI Live reports the desired AFR as 14.37 MY WOT also reports richer in EFI Live (14.37/1.165).
What I'm asking is why would EQ1=14.37 if I dont have a flex fuel vehicle?

Because you changed the value of AFR=EQ1
All it does is put an AFR number to EQ.
Changing the Stoich AFR value will change other tables when viewed in AFR but
will not actually change the amount of fuel delivered.

This can be changed if you are using AFR instead of EQ/Lambda to tune and
your WBO2's is not able to change Stoich AFR=Lambda1 to match EQ1.
It's not necessary as long as EQ is properly set i.e. not lean during PE

FYI
If your WBO2 is not able to change the AFR value=Lambda1 then make a calc_pid.
6" from the end of the tailpipe is not a good place for a WBO2,
3' from the end is minimum.

[CalEditor]

Hey guys, I posted this over at the tunercats forum monodax.com also.
I was under the impression that changing the values in the stoich AFRvs % alcohol in fuel table would make NO difference to my vehicle: 2005 4.8L Tahoe NON FLEX FUEL.

Incorrect

[TunasTwins]

Incorrect

Please explain. The vehicle is NON flex fuel. Did I effectively change the EQ? Will this change the target AFR in closed loop also? Is changing the 02 switch point mandatory? TIA

[CalEditor]

Please explain. The vehicle is NON flex fuel. Did I effectively change the EQ? Will this change the target AFR in closed loop also? Is changing the 02 switch point mandatory? TIA

Did you post a question on another forum?

I will try to explain, but I need to pull an earlier flex cal first

[mr.prick]

What's more to explain?
You changed the AFR value of EQ1, this changes all Commanded AFR values.
(Stoich AFR/Commanded EQ)=Commanded AFR.

[bmax]

I have been following this also.

I am wondering, don't the narrow bands only read stoich.
Can the computer compensate for the difference in commanded?

When I get a chance I will do some logging to see the difference but it seems that even if you command 14.37 that the narrowbands will still look for 14.63.

Or I may be way off base. Do the switchpoints make that difference in the stoich points?

Any insight?

Brad