Calc.VET: correcting MAF and calculating VE (in single log)

[redhardsupra]

I still don't understand how is your fuel trim derived BEN any different from trims alone, or the classic BEN. Care to explain that, and I don't mean anecdotal evidence that ends with '..but it works for me' but have an actual derivation?

[WeathermanShawn]

I still don't understand how is your fuel trim derived BEN any different from trims alone, or the classic BEN. Care to explain that, and I don't mean anecdotal evidence that ends with '..but it works for me' but have an actual derivation?

This Calculated Pid is the definition of the 'Airflow Correction' Term(s).

"iff({CALC.PE},{CALC.WO2BEN1}, {CALC.LTFTBEN})"

{SAE.MAF.gps}*({GM.DYNAIRTMP_DMA.C}+273.15)*3445.2/(5.669*{SAE.RPM}*{SAE.MAP.kPa})*{CALC.SELBEN}"

The first few terms defines PE Mode, the last two say use WO2BEN if it is in PE Mode or LTFTBEN if is not in PE Mode.

[redhardsupra]

yes, I can read equations. where did it come from? how did you arrive at it?

[WeathermanShawn]

yes, I can read equations. where did it come from? how did you arrive at it?

Welcome to one year ago Marcin...

http://forum.efilive.com/showthread....l=1#post117351
http://forum.efilive.com/showthread....044#post117044
http://forum.efilive.com/showthread....048#post117048

[redhardsupra]

oh ok, so Joecar did all the heavy lifting, which is a complete rehash of my Sept 2006 paper, and then you respun it into some sort of 'methodology'. DJ Shawn and the WeatherGirls are mixing it up, yo...

[WeathermanShawn]

For the record....

The derivation of the CALC.VE & CALC.VET came 100% from the formula found in the EFILive Tune Tool (VE Table).

I sent Joecar my 'formula' and the results of the initial testing. Yes, Joecar did all the heavy lifting and humbly took little praise.

In reality you could take the CALC.VET formula..make the 'airflow correction' 1.00, and substitute your own 'airflow correction'. Or you could simply take the MAF Airflow, and substitute any airflow parameter you wanted. Then you can define your own methodology.

Thanks for your 2006 work. We finally got it to work!.

[Wolfie]

I am thinking that DFCO should be disabled.
I am also thinking that nothing else needs to be changed.
I am also also thinking, actually was thinking, now thought, and finally realized, that doing things by the numbers actually works...
ie: getting it through my thick head that B3601 ( - The air-fuel ratio (AFR) considered to be stoichiometric) actually does need to be right... (sigh...)
It works just fine. Although short(er) logs than 1000 miles are better!
Anyway, thanks for your work Shawn!

[WeathermanShawn]

Thanks Wolfie..

Ultimately disabling DFCO probably produces better results. Its odd..when you are in closed-loop and DFCO initiates, the LTFTBEN 'freezes' at the particular FTC..MAF, MAP decreases..so you get a somewhat reasonable low MAP VE % calculation.

Now when you are in PE Mode and shift (M6-DFCO), your AFR will spike and your VE % will not be accurate at that particular point. So, thats where the CALC.VET Filter comes in..I.E. ECT, and rapid TPS % are filtered out. So, good filtering eliminates the erroneous DFCO events.

I agree Disabling DFCO is probably superior to filtering. In all honesty, Wolfie I have struggled to keep the method as simple as possible. I know it sounds ridiculous that disabling DFCO is advanced, but you probably understand where I am coming from...

Thanks, and yes keep those logs under 1000 miles.. .

[joecar]

oh ok, so Joecar did all the heavy lifting, which is a complete rehash of my Sept 2006 paper, and then you respun it into some sort of 'methodology'. DJ Shawn and the WeatherGirls are mixing it up, yo...

Yes, I did read your paper which pulls together the equations for AFR, IPW, airmass/airflow, IGL to arrive at GMVE[g*K/kPa] and VE[%]: http://www.marcintology.com/tuning/HowSpeedDensityWorks16.doc.



(IGL has been around a long time, airmass/airflow more recent but still a number of years)

I took the equations for airmass/airflow and IGL and by a different route arrived at VE[g*K/kPa] and VE[%] in terms of log-able pids; we needed a VE pid that we could rely upon, see the thread on DYNAIRTMP_DMA vs CHRGTEMP_DMA.



Shawn came up with the idea of correcting the MAF using LTFT and/or WB before calculating the VE... this gives two abilities in one log: corrects the MAF, and calculates VE from corrected MAF.

[Frozen WS6]

Question. I'm making my maps in the scan tool. I made VET (Average). Which is RPM/Map and I added the data filters.
I'm having trouble getting the SELBEN map right. I get MAFFREQ showing in the Row. I don't list a MAF Sensor Calibration option. I only have a MAF (Grams per second) or MAF (Pounds per minute) option. Also how do I make the map just show the Value like in Attach #9823.