Question about VE air, MAF air, and Dynamic air

[GHuggins]

I was using a formula with air fuel correction based off of injector flow and MAT - worked rather well and turned VE tuning into about an hour or 30 minutes compared to the almost half a day it was taking before... But like I said - I never got the MAF one figured out and lost my formula when I switched to 2.25 or 3.0?

Very happy Barum posted these and good to know I still need to use a correction factor if tuning both at the same time - I'll see how well the MAF one works out on the next tuning job...

[JBZ]

So much great info here. Thanks to all of you guys

JBZ Try this: EQ ratio (AFR) * (inj PW B1 + inj PW B2)/2 * injector flow rate * intake air temp/ MAP. Your parens were keeping you from getting an average injPW.

Good call and thanks. Yeah i have another pid set up for calculating average pw and your correction is how i had set it up in that previous pid. I must have messed it up in doing this pid, i was making all kinds of corrections while trying to figure this out. Funning thing is...it actually worked to some degree. It really only skewed my data on transitions...guessing alot to do with filtering.

[rjw]

There are several ways to calculate (approximated = assuming some fixed ratio between IAT and ECT) GMVE.
These are the formulas I've been using with 2.24 version, but I haven't done the conversion to 3.x series variable names yet.

I took me a while to gather all the pieces from here and there (thanks Marcin for your work) to be able to update the GMVE table from almost any log with correct filtering.


Calculated GMVE (from Dynamic Airflow)

[PID.2320]/([SENS.70]/15*0.875*[SENS.30]/0.28705/(273.15+[SENS.11]))*875/0.28705

GM Volumetric Efficiency = Dynamic Airflow[g/s] / ( RPM[1/min]/15 * Displacement[l] * MAP[kPa] / 0.28705 / (273.15 + IAT[C]) ) * Displacement[cm3] / 0.28705


[PID.2320]*(273.15+[SENS.11])*1000*15/([SENS.70]*[SENS.30])

GM Volumetric Efficiency = Dynamic Airflow[g/s] * (273.15 + IAT[C]) * 1000 * 15 / ( RPM[1/min] * MAP[kPa] )



Calculated GMVE (from MAF)

[SENS.40]/([SENS.70]/15*0.875*[SENS.30]/0.28705/(273.15+[SENS.11]))*875/0.28705

GM Volumetric Efficiency = Mass Air Flow[g/s] / ( RPM[1/min]/15 * Displacement[l] * MAP[kPa] / 0.28705 / (273.15 + IAT[C]) ) * Displacement[cm3] / 0.28705


[SENS.40]*(273.15+[SENS.11])*1000*15/([SENS.70]*[SENS.30])

GM Volumetric Efficiency = Mass Air Flow[g/s] * (273.15 + IAT[C]) * 1000 * 15 / ( RPM[1/min] * MAP[kPa] )



Calculated GMVE (from cylAir which is derived from Dynamic Airflow)

[PID.2321]*(273.15+[SENS.11])*1000/[SENS.30]

GM Volumetric Efficiency = Cylinder Airmass[g] * (273.15 + IAT[C]) * 1000 / MAP[kPa]



Calculated GMVE (from WBo2)

([PID.6200]+[PID.6201])/2000*[PID.6210]*[AUX.20121]*(273.15+[SENS.11])*1000/[SENS.30]

GM Volumetric Efficiency = (InjectorPW_B1[ms] + InjectorPW_B2[ms]) / 2000 * InjectorFlowRate[g/s] * WideBandO2AFR * (273.15 + IAT[C]) * 1000 / MAP[kPa]


([PID.6200]+[PID.6201])/2000*[PID.6210]*[AUX.20122]*[PID.6001]*[PID.68]*(273.15+[SENS.11])*1000/[SENS.30]

GM Volumetric Efficiency = (InjectorPW_B1[ms] + InjectorPW_B2[ms]) / 2000 * InjectorFlowRate[g/s] * WideBandO2Lambda * CommandedAFRHiRes * CommandedEQRatio * (273.15 + IAT[C]) * 1000 / MAP[kPa]


([PID.6200]+[PID.6201])/2000*[PID.6210]*[AUX.20122]*[SENS.121]*[PID.68]*(273.15+[SENS.11])*1000/[SENS.30]

GM Volumetric Efficiency = (InjectorPW_B1[ms] + InjectorPW_B2[ms]) / 2000 * InjectorFlowRate[g/s] * WideBandO2Lambda * CommandedAFR * CommandedEQRatio * (273.15 + IAT[C]) * 1000 / MAP[kPa]


Depending on the mode (OL or CL, SD, Hybrid or MAF only) it is necessary to choose the best suited calculation method. Generally cylAir gives the best quality but I have used also an average of all four.

does anyone have all this converted to V3.2?

thx

[mowton]

working it...if you are doing it remember to use sensor parameters where ever you can so the equation is as generic as possible.

Ed M

[schpenxel]

does anyone have all this converted to V3.2?

thx

Here's two of them.

(Dynamic Airflow)
[2320.71]*(273.15+[50011.241])*1000*15/([50070.56]*[50030.91])

(Wideband in lambda)
([50151.254]+[50152.254])/2000*[6210.71]*[50127.238]*[50121]*[50118.239]*(273.15+[50011.241])*1000/[50030.91]

I haven't confirmed with a car that is pretty far off.. but for something that's already tuned when I logged GMVE and both of these ways of calculating GMVE it came up with almost exactly the same thing. I'll see how they do on something less tuned later. The dynamic airflow one was closer, the wideband one jumped around more

[JBZ]

does this look right? this is calculated from cyl air

[50041.223] * (273.15 + [50011.241]) * 1000/[50030.91]


edit: ive attached all the maths that I have so far in hopes that the guys who don't want to do it long hand can just drop these in...but they may still need to be updated and revised if they are not correct. ill add to them as we continue to get more of these figured out for HPT 3.X


by the way this is one of the coolest threads im proud to be part of. thanks again guys


edit: added MAF calc

[josh99frc]

I have been trying to figure this out from the links and previous discussions over the years and to be honest there wasn't a chance in hell of me figuring this out on my own. Thank you to all parties involved now and thought the years. Ive been happier than a 6 year old on christmas day since JBZ told me this thread was going on.

[mowton]

OK, I'll stop, looks like you guys got it complete.....

Now this is funny Josh.....

Ive been happier than a 6 year old on christmas day since JBZ told me this thread was going on.

Ed M

[rjw]

No, please don't stop...lol this is all good

question: I've been logging EQ error on a chart with rpm vs pressure ratio. Would it be just a matter of plugging in these formulas in place of eq error, and keeping the rpm vs pr?

also, correct me if I am wrong, but I would need to remove maf related sensors from my channels list?

Yes, I am confused...

thx

[JBZ]

Here's two of them.

(Dynamic Airflow)
[2320.71]*(273.15+[50011.241])*1000*15/([50070.56]*[50030.91])

(Wideband in lambda)
([50151.254]+[50152.254])/2000*[6210.71]*[50127.238]*[50121]*[50118.239]*(273.15+[50011.241])*1000/[50030.91]

I haven't confirmed with a car that is pretty far off.. but for something that's already tuned when I logged GMVE and both of these ways of calculating GMVE it came up with almost exactly the same thing. I'll see how they do on something less tuned later. The dynamic airflow one was closer, the wideband one jumped around more

so for what ever reason and I don't know why, that wideband in lambda equation wasn't working for me. it was dropping everything by quite a bit (even to a completely stock LSA tune file VVE table) so I moved over to this one (the first one from Barum) and it seemed to line up much better.

GM Volumetric Efficiency = (InjectorPW_B1[ms] + InjectorPW_B2[ms]) / 2000 * InjectorFlowRate[g/s] * WideBandO2AFR * (273.15 + IAT[C]) * 1000 / MAP[kPa]
([50151.254]+[50152.254])/2000*[6210.71]*[50127.234]*(273.15+[2128.241])*1000/[50030.91]

[Eaglegoat]

All gen 4 vehicles have MAT. Use MAT. Also, stop covering into Kelvin and just set the MAT temperature usage to Kelvin. Stop adding unnecessary things like both banks IPW. You should be doing this in open loop so both banks will have the same pulsewidth.

Most of this is in your scanner under Tools>Math Parameters>Maths - Predefined>Cylinder Airmass.
Those aren't lambda corrected though.

Also remember that The injector pulsewidth one won't work properly on gen3 stuff.

[schpenxel]

so for what ever reason and I don't know why, that wideband in lambda equation wasn't working for me. it was dropping everything by quite a bit (even to a completely stock LSA tune file VVE table) so I moved over to this one (the first one from Barum) and it seemed to line up much better.

GM Volumetric Efficiency = (InjectorPW_B1[ms] + InjectorPW_B2[ms]) / 2000 * InjectorFlowRate[g/s] * WideBandO2AFR * (273.15 + IAT[C]) * 1000 / MAP[kPa]
([50151.254]+[50152.254])/2000*[6210.71]*[50127.234]*(273.15+[2128.241])*1000/[50030.91]

Weird. I only tried it on a few logs so maybe I just got lucky

[josh99frc]

I have everything scanning from the attachments that JBZ uploaded and the WBO2 one isn't logging any info its tracking through the cells just not showing anything. I run dayton sensor reading lambda off of my Mpvi. Ive tried a couple things but its not getting me anywhere. Any help would be greatly appreciated. I attached two screen shots.

[mowton]

only took a quick look, on with a client, but why would you mix AFR and Lambda?

Make sure you have transformed your wb to that label you have used. That is why it is red.

Ed M

[JBZ]

I have everything scanning from the attachments that JBZ uploaded and the WBO2 one isn't logging any info its tracking through the cells just not showing anything. I run dayton sensor reading lambda off of my Mpvi. Ive tried a couple things but its not getting me anywhere. Any help would be greatly appreciated. I attached two screen shots.

50127 is showing up red because its not a valid sensor. open that custom math...click on 50127 and hit edit, go find your wideband in the parameters list and try it again. that eq ratio is the AEM 30-0333 can bus address and sensor.

BTW go re-grab that math parameter and revise it from my post 46. I changed it to another one of barums formulas because it wasn't working right...for me anyways. the one your using is the older one...after that you will still need to swap 50127 with your wb sensor

why would you mix AFR and Lambda?Ed M

I was following this PID from Barum

([PID.6200]+[PID.6201])/2000*[PID.6210]*[AUX.20122]*[SENS.121]*[PID.68]*(273.15+[SENS.11])*1000/[SENS.30]

GM Volumetric Efficiency = (InjectorPW_B1[ms] + InjectorPW_B2[ms]) / 2000 * InjectorFlowRate[g/s] * WideBandO2Lambda * CommandedAFR * CommandedEQRatio * (273.15 + IAT[C]) * 1000 / MAP[kPa]

but have now changed it to this one as it seemed to be on point

([PID.6200]+[PID.6201])/2000*[PID.6210]*[AUX.20121]*(273.15+[SENS.11])*1000/[SENS.30]

GM Volumetric Efficiency = (InjectorPW_B1[ms] + InjectorPW_B2[ms]) / 2000 * InjectorFlowRate[g/s] * WideBandO2AFR * (273.15 + IAT[C]) * 1000 / MAP[kPa]

[josh99frc]

Custom math at this level is so foreign to me I wouldnt know if something wasnt right unless someone pointed it out. So thank you for setting me straight. At this point im trying to get it all reading right then go back to understanding exactly how it all works. Having a fast car is sweet but I just love being able to understand exactly how it all works. Running off to work for the rest of the night, gonna implement your suggestions and report back tomorrow.
Thank you again

[schpenxel]

Is your wideband setup in Lambda ("EQ Ratio") or AFR?

It has to be in lambda for that PID to work. It being red makes me think it's not setup in lambda.

[josh99frc]

Eq ratio I used the predefined info that hp provided for daytona wego

[JBZ]

Is your wideband setup in Lambda ("EQ Ratio") or AFR?

It has to be in lambda for that PID to work. It being red makes me think it's not setup in lambda.

that one is from my log which I use the same AEM as you so you could essentially plug it in and it work, but Josh is using a different sensor so...well as you know he needs to go into the channels list from that math parameter and select his wb

[barum]

I was following this PID from Barum

([PID.6200]+[PID.6201])/2000*[PID.6210]*[AUX.20122]*[SENS.121]*[PID.68]*(273.15+[SENS.11])*1000/[SENS.30]

GM Volumetric Efficiency = (InjectorPW_B1[ms] + InjectorPW_B2[ms]) / 2000 * InjectorFlowRate[g/s] * WideBandO2Lambda * CommandedAFR * CommandedEQRatio * (273.15 + IAT[C]) * 1000 / MAP[kPa]

The blue part is the amount of fuel going through the engine (per combustion) and the red part of the equation converts it to the corresponding amount of air.

CommandedAFR takes care of the gas/ethanol blend, CommandedEQRatio cancels out any enrichment due to warm-up or PE included in the CommandedAFR and finally the WideBandO2Lambda (yes, lambda not AFR) corrects errors in calibration as it's the feedback from the real world.

JBZ, if it's not working for you, I would double check all the parameters used so that they correspond to those of 2.24.

My thinking was to use any way possible to calculate the air going through the engine as that's one of the main components in VE calculation, no black magic there.