using 14.047 for desired AFR and not 14.63?

[98 tigershark]

5.7ute, that is ingenious. I will make a few adjustments, try it and log before and after and post the results. Anyone else want to try this and compare logs?
98 tigershark

It would be an easy test 98 tigershark.
Compare the commanded AFR in a log with 14.63 in B3601 to a log with 14.07 in B3601.
Since the computer thinks in EQ, changing this calibration should cause a change in commanded AFR.

[98 tigershark]

Before I do this it would be nice to know for sure that you guys dont already know what is going to happen. I think also that I am more than willing to do this but it would be best if we could get 3 or 4 of us as to compare for accuracy and then we could compare logs and see for sure. Are you guys sure you dont already know?
98 tigershark

[5.7ute]

I can have a look after work with the Roadrunner hooked up.(In about 9 hours) You would see an instant change in commanded AFR that way.

[98 tigershark]

hello vetteboy,

I want to make it perfectly clear that I do not know the answer to this but it would seem that we could then use E85 and the PCM would automatically adjust to stoich regardless of fuel as the sensors would show a very lean condition and then adjust the trims to a 1 EQ accordingly?
That still does not sound right. I am certainly not saying anyone is wrong as I do not know, It just sounds wrong to me with the 97-2004 PCMs.
So are you interested in trying a little experiment 5.7ute suggested?
Using 14.07 for afr and comparing logs?
Looking for help,
98 tigershark

I believe the narrow bands will adjust to stoich of whatever the AFR is of the fuel your running. So if pure gasoline they will adjust to stoich which is 14.68 and if E10 14.07 being stoich is stoich and the sensors don't know the type of fuel your running.

[98 tigershark]

Thanks 5.7ute,

That is a very nice offer if you have the time and it does not have to be today as you are probably very tired late in the day. But when you can find the time that sounds great as I think this will become more and more of an issue with fuel in the future. I would sure appreciate getting my brain around this and knowing for sure (It took me getting a serious brain disease to prove to my wife I had a brain, really). I may be wrong but I think when you put 14.07 into B3601 that becomes the EQ of 1. I guess we shall see soon enough. Thank you so much and I am still willing to try it, but I think we need a few volunteers to compare logs and notes as I am not a pro at this ind of thing.
98 tigershark

I can have a look after work with the Roadrunner hooked up.(In about 9 hours) You would see an instant change in commanded AFR that way.

[5.7ute]

I am doing some idle work on my car after work anyway. I will let you know what I find.

[98 tigershark]

That is way cool, Thank you!
98 tigershark

I am doing some idle work on my car after work anyway. I will let you know what I find.

[mr.prick]

It would be an easy test 98 tigershark.
Compare the commanded AFR in a log with 14.63 in B3601 to a log with 14.07 in B3601.
Since the computer thinks in EQ, changing this calibration should cause a change in commanded AFR.

It will and it will change the AFR values in {B3605}

[5.7ute]

It will and it will change the AFR values in {B3605}

That is a good point mr.prick. You need to close & reopen the tunetool though to have it take effect.
What this tells you is that by changing {B3601} to match the stoichemetry of the fuel you are using, your enrichment percentages will remain intact. There is no need to recalibrate any of the commanded fuel tables.(unless of course you want a different enrichment percentage for the new fuel)
It also highlights the need to set {B3601} to the stoichemetry of the fuel you are using when doing autoVE with any commanded EQ not equal to 1.0. (like in a custom OS where STFT are enabled when commanding stoich.)

Once again a new thread points out a new trap in previous methods of tuning.

[SSpdDmon]

That is a good point mr.prick. You need to close & reopen the tunetool though to have it take effect.
What this tells you is that by changing {B3601} to match the stoichemetry of the fuel you are using, your enrichment percentages will remain intact. There is no need to recalibrate any of the commanded fuel tables.(unless of course you want a different enrichment percentage for the new fuel)
It also highlights the need to set {B3601} to the stoichemetry of the fuel you are using when doing autoVE with any commanded EQ not equal to 1.0. (like in a custom OS where STFT are enabled when commanding stoich.)

Once again a new thread points out a new trap in previous methods of tuning.

I'm trying to follow along and I think I agree. Basically, there's two things going on here. One is with the software (EFI Live) and the other is with the PCM/tune. When you display AFR instead of EQ in EFI Live, the software is simply converting EQ to AFR for you on the surface based on 14.63. However, in the background - EQ is still loaded into the car when you flash the file. Unfortunately, the AFR setting can't be changed away from 14.63 in the preferences. **Maybe with a little tweak to some code it could.** But as of now, it can't. So, any table that that opperates based on EQ in your tune file will be converted to AFR when viewed in EFI Live under the assumption that you're using 100% gasoline.

What this means is...let's say you're using 10% ethanol with a true stoich of 14.08 and your display preferences in EFI Live are to show AFR. So, you set 3601 to 14.08 (this cell is not affected by the display settings). In your PE (which is still showing AFR based on gasoline), say you have it set to command an AFR of 13.0. In the background, the real number that gets loaded into the PCM is 1.13. Therefore, you should see a commanded AFR in your log of 12.46....not 13.0....since you changed 3601 to 14.08 (14.08/1.13=12.46).

To avoid confusion, you ideally want to operate with EQ and set 3601 accordingly. But even if you don't switch off of AFR in the display preferences, it shouldn't be as dramatic of an inaccuracy as some have made it out to be. You just have to remember, what shows in AFR when looking at the tune file through the software is based on gasoline....not what you have in 3601. As long as you remember that, the PCM *should* adjust accordingly assuming you are using the right B3601 and you're looking to use the same enrichment ratio (EQ of 1.13 in my example) for the fuel you're using.

Sorry if I lost anyone - probably could explain it a little clearer. But, I'm exhausted right now... LOL