calc.ve .pid wrong?

[SSpdDmon]

There's a calc pid in the scanner I just noticed that computes a VE value based on MAF. The equation shows:

VEpcm=MAF*(IAT+273.15)/((displacement()*61.024)*RPM*MAP)*6155274.24

I didn't get any values that made sense with that and I wasn't sure how to represent displacement.

So, I tried the following:

VEpcm=(MAF*(IAT+273.15)*6155274.24)/(displacement*61.024*RPM*MAP)

...using cylinder_volume*8=5665.527336 for displacement and metric values for MAF, IAT, and MAP.

The result appears to be relatively close to my VE in grams*K/kPa.

Is it possible this calculated pid's equation is wrong in the EFI Live sae_generic.txt file?

[joecar]

Jeff, I pm'd Paul.

[johnsZ06]

Subscribe

[Blacky]

The value of the displacement() function is determined by the displacement setting in the log file.

You can view/change the displacement setting in the log file here:
Edit->Log file information...->Vehicle Options->Engine:
Select from the list, or just type in the displacemnt in CC.

You can set the default displacement for a particular VIN in the customer details. The customer details are copied into a log file when it is recorded.

Regards
Paul

[mnotx]

I have done just that and still can't get the VE to work on old logged data(V1). Do I have to log new VE data before it will work?

[Blacky]

I have done just that and still can't get the VE to work on old logged data(V1). Do I have to log new VE data before it will work?

No, once you update the displacement value in the log file (and replot the charts), then the calculated PID's value should reflect the new displacement.

Just to check the displacment is being picked up correctly, create a calculated PID with just "displacement()" as the expression. That should be a straight line at the value of the displacement.

Regards
Paul

[mnotx]

The value of the displacement() function is determined by the displacement setting in the log file.

You can view/change the displacement setting in the log file here:
Edit->Log file information...->Vehicle Options->Engine:
Select from the list, or just type in the displacemnt in CC.

You can set the default displacement for a particular VIN in the customer details. The customer details are copied into a log file when it is recorded.

Regards
Paul

Since I don't know how to creat my own PIDs, is there another way to test and see what is wrong. I did the above, but the VE still does not work.

[Blacky]

There is a "gotcha" when setting up the displacement value for a log file. If the displacement is not set (i.e. set to 0) then EFILive defaults to displaying 5669 cc (i.e. LS1 5.7 liter). Unfortunately, it still uses the 0 value in the calculated PIDs, which is what has been confusing everyone - me included).

Workaround:
1. Load the log file.
2. Select the menu option Edit->Log file information
3. Select tab page [Vehicle options]
4. Change the "Engine: CC" setting to a different value.
5. Click on Ok.
6. Save the log file.
7. Repeat steps 2-6, but select the correct engine size.

Attached is a calc_pids.txt file that shows the value of the "displacement()" function. To display in cubic inches, right click on the CALC.ENGSIZE PID is the [PIDs (F8)] tab page and select Imperial (or select Metric for cubic centimeters).

Regards
Paul

[joecar]

Posts #4 and #5 don't follow on from post #1...

[mnotx]

Posts #4 and #5 don't follow on from post #1...

My post was in response to Blacky's. My point was that I did what should have fixed the problem and it didn't. My VE PID worked under V1, but has not worked since upgrading to V2. I simply would like to get VE working again.