First attempt at CALC VET please check for sanity

[Strong05]

I've been away from this for a little over a year now and I'm trying to dust out the cob webs and learn the new CALC VET method. Please take a look at my log and calc_pid and make sure I didn't miss something.

Thanks in advanced for the help!
Brad



12907

12908

[joecar]

Hi Strong,

You have an LC-1 connected thru the analog interface, right...?

[Strong05]

Yup sure do, sorry forgot to mention that. I think I got the calc_pid file equation correct for the analog setup. I never followed through on trying to do the serial connection for my LC-1.

Thanks,
Brad

[joecar]

In the calc_pids.txt where it says displacement(xxxx), delete the xxxx;

the displacement is entered by going Edit->Log File Information->Vehicle Options and entering the CC there (in the Engine: field), and then saving the log file;

the scantool will automatically replace "displacement()" with the correct value/units (5.669L).

[joecar]

So do this:
- in your calc_pids.txt, change "displacement(5.669)" to "displacement()" [ i.e. remove the 5.669 from within the parentheses ], and save the file;
- start the scantool, go Edit->Log File Information->Vehicle Options, and set the Engine: field to 5669 CC, click Ok, save the log file.

[Strong05]

That's really weird because at first it showed up as all zero's, then it dawned on me tonight why I had values for the unit PID but not the percentage PID on the table. So I did exactly what you said above and it then neatly filled in the info. So I'm not sure why that value is there. I started off by filling it in then I thought I deleted the value because after reading the threads I understood that the info is filled in when you select the engine size in the scan tool (or I understood as you described above). I'll re-delete the engine displacement out of the file though just to be sure.

[joecar]

There is an improved calc_pids.txt file (it separates out DAT so you can chart it)...

I added your AFR_LC11/14.7 modification into the WO2BEN pid, see attached... copy it to the usual place and restart the scantool (no need to relog).

[Strong05]

I think I just forgot to save after I thought I deleted the displacement value out of the equation. It's correct now though. Still strange that if the value were in the calc_pid file I would think the VET table would have filled in correctly instead of all zeros.

[joecar]

Quick question: did you disable the VE by setting B0120 to 400 or less...?

[Strong05]

Sure did... see attached.

12910

[Strong05]

This is probably a dumb question but what is DAT? I don't recall that being discussed in any of the CALC VET threads I've caught up on.

Thanks,
Brad

[joecar]

Brad,

DAT is this thing: ({GM.DYNAIRTMP_DMA.C}+273.15)

I separated that out as CALC.DAT so you can display CALC.DAT.F on the chart/gauge (so you can check that DAT falls between IAT and ECT).

[Strong05]

dang it... I just checked B0120 and it's set to 4000... could have swore I set it to 400.

[Strong05]

Interesting that they use Kelvin... Whats the significance of that being between IAT and ECT? Where/how is the ECU coming up with DYNAIRTMP?

[joecar]

Interesting that they use Kelvin... Whats the significance of that being between IAT and ECT? Where/how is the ECU coming up with DYNAIRTMP?The PCM blends IAT (intake air temp) and ECT (engine coolant temp) to calculate the temp of the air entering the cylinders... the internal pid for this is DYNAIRTMP_DMA;

DAT takes that and makes it easily accessible in Kelvin, since the calculation uses the Ideal Gas Law PV=nRT (from Physics) to calculate the VE table.

[Strong05]

Guess that means this is basically garbage... oh well at least it's supposed to be a super nice out for a drive this weekend! Thanks for taking a look at it for me Joe!

[Strong05]

Gotcha, despite my best efforts to flush thermo from my memory I still recognize that equation. Just don't ask me to use a look up chart or to interpolate anything!

[joecar]

dang it... I just checked B0120 and it's set to 4000... could have swore I set it to 400.


Guess that means this is basically garbage... oh well at least it's supposed to be a super nice out for a drive this weekend! Thanks for taking a look at it for me Joe!

Yea, I know, stuff happens... :doh:


You might be ok, because the transient filter will remove any data contributed by transients which includes when the VE kicks in...

just try it to see, but yes, back it up with another log, see if you get the same result.

[Strong05]

Interesting I thought the transient filter was just for the throttle. I'll probably do another run tomorrow just to be safe. I might take a look at both and see if there are any differences. I think the tune is pretty close as it is. I only changed the cat back part of the exhaust and the throttle body from when I tuned it last.

[joecar]

When the throttle moves (causing a transient airflow/airmass condition), if the RPM is under B0120 then the VE kicks in (the PCM has some algorithm for this)... so the transient filter just happens to remove VE contributions... but yes, it is better to take another log with VE disabled (via B0120).


Here is what I get from your log file when I hide low count cells and apply the transient filter (paste CALC.VET into VE and paste-multiply CALC.SELBEN into MAF), see attached.