Whats a good range of BEN factor for MAF

[pavetim]

It looks like i'm chasing my tail on tuning the MAF. What is a good range, I got most near 1 but the high and low ranges are like 1.04 at the very highest, and .98 at the lowest. Most are like 1.01, and 1.02. I know you want to try and get them as close to 1.0 as possible but what is a good range for these?

[WeathermanShawn]

Thats normal.

An average of 1.00 is the best you will ever get. On a given day they can vary +/- 2-3%.

[pavetim]

Ok then the MAF is done, just need to work on some cells on the VE table. I tuned/logged today with my WB and no LTFT/STFT. Working good so far, a few cells have me running around though. The PE stuff is coming in nicely though. How much do the NB correct for? Like if i'm getting 14.3 on my WB will the NB correct back to 14.68 or should I work on the VE table more if my WB is showing like 14.3? I know you'll never get it perfect but what is normal when tuning.

[WeathermanShawn]

You have kinda lost me there..

If you are tuning with no LTFT or STFT, then you are not running closed-loop. With CALC.VE Table you are not running off the VE Table per se.

What technique are you doing?

[pavetim]

I did the CalcVE with the LTFT and got pretty close, but couldn't do the PE/WOT cause I didn't have my WB yet. But got my WB now and figured i'd start over again. But since I had to pull a NB out to put my WB in I had to disable LTFT/STFT since there is only one NB. So basically I was doing Open loop-MAF.

[pavetim]

Here is the last log i did tonight. Looks fairly good just can't the top row where it's showing over 15 afr. And a couple odd ball ones.

[WeathermanShawn]

Mmmm. See thats not a great idea. It never occurred to me that someone would utilize closed-loop via CALC.VE Table and then disable a NB to utilize PE mode..but then re-do the tune as an open-loop MAF.

Why not just put a bung in for the WB and still utilize the NB? Might take a few minutes to weld a bung in, but tuning-wise it would make it a lot easier.

I guess you could just use the BEN1 for your MAF..but in all honesty the CALC.VE Table was not set-up that way. You would need to set B0120 to 400 RPM's for a open-loop MAF Tune.

Tim, my technique is to utilize the NB for closed-loop and the wideband for PE Mode/WOT. If you use a different bung for your WO2 it would work. You would need to go back to closed-loop or just do an OLMAF Tune.

This is a new one. I would have to think it over as to the easy solution..

[pavetim]

I hear ya, I told him to get a bung welded in, should have it monday. Thats what happens when you don't have all your ducks in row lol, pieceing stuff together. You think my log is close enough to not worry much about it, or needs more work? I'm not super concerned it's only a 4.3, it's more of a practice/learning tune for me. Ok if i went back and got the bung welded in and started the CalcVE tune all over again. Would I use the LTFT BEN still or would I use the WO2 BEN? I'm guessing the NB are more accurate at stoich?

[WeathermanShawn]

Well its a little hard to tell..Generally the AFR's look 'O.K.' Did you log BEN1 at all? I did not see it on my Scan Tool. I believe you have to have the PID 'EQUIVALANCE RATIO' selected also.

If you log both LTFTBEN and WO2BEN simultaneously (depending on PID Channels) then it is so easy it is not even worth explaining. For closed-loop its all NB, for PE/WOT it WO2BEN. You hit the MAF Table with the corrections..run another Log and everything is done.

Looks like you averaged 13.0 AFR at WOT. Is that what you wanted?

[pavetim]

I want 12.8 @ wot I made an adjment just havent run it yet. I got alot of calc pids what ben do I use for wb afr I did not have a equivalent pids selected though.

[WeathermanShawn]

Actually your open-loop MAF tune was not that far off. You must have got it close when you did it via the NB's.

I usually just use the 'canned' BEN Factor 1, Serial Wideband LS1..See Attachment.You have to have each of those PIDS in the equation selected to have a CALC.Pid work.

So your Tune experiment was actually pretty close. I would still try to do it using both NB's and WO2. 12.8 AFR vs 13.0 is within 1-2%, and even your closed-loop AFR's were pretty decent..

[mr.prick]

I have {EXT.WO2AFR1}/{GM.AFR} for the "canned" Serial BEN PID.

[pavetim]

So i'd log LTFTBEN and BEN1 at same time. Filter excluding PE mode and copy/paste-multiply the LTFTBEN to the VE table. Then Filter out including PE mode and copy/paste-multiply BEN1 into VE table, sound about right when you log both NB and WB pids at same time? And why do guys like to use EQR over AFR is EQR more accurate?

[WeathermanShawn]

Tim it is all about the MAF Airflow. I know I am repeating myself, but when you log MAF Frequency, MAF Airflow (g/s), LTFTBEN and either the 'WO2BEN' I use or Mr.Prick displayed, you are calculating a representative VE Table from the MAF Airflow.

At some point you just have to have faith it works, or you will forever be confused. The reason EQ is ultimately favored is because of the ever increasing availability of ethanol and ethanol related fuel blends. They burn differently and if you use AFR all your fueling calculations will be incorrect. It can be very confusing..it took me months to figure all that out.

Tuning-wise it takes months sometimes to nail down a new tuning concept. You just need more practice. I think we have given you all the theory you need for now.

Good luck..

[pavetim]

think I got it now just have to learn to get some good filters to filter out PE and non PE mode.