Calculating VE from MAF and MAP sensors

[Scot Sealander]

Chris Bennight wrote:
  
> |
> | Where are you getting "T" (air temp) in your setup?  How accurate
> | do you think it is?
> 
>    On an LT1, using the IAT (incoming air temperature sensor).  It is
> located a bout 4" from the TB, and excepting possibly heatsoak issues
> it should be farily accurate.   It tends to run just a bit hotter than > ambient.

I did not have good results with air temp sensor in the manifold.  Just
my experience.   I put it after the intercooler, and model any temp
changes.  This modeled temp is displayed in the DIACOM start coolant
temp field.


> What did you do about coasting issues?

Fixed the errors.  Typical VE at 25 kPa is about 41-42%  The MAF and
tables
VE's may vary some.  Table VE may be 43-44%.  Still some error, but I
don't
know who is correct. MAF or SD.....


> I had to write a parser
> to take out all samples that had negative acceleration - the VE values
> I would calculate in these cells were WAYY off - running about 160-
> 200%   (since MAP was VERY low - ~20KPA, while airflow
> still scaled with rpm somewhat.

Gotta figure out where the error is.  What is MAF VE at those locations?
What is the table VE?

DIACOM for the TGP has three fields that us percent.  Percent EGR,
Percent 
CannPurge and percent WasteGate.

Presently, for this cal,  corrected VE is displayed in one of those
fields, MAF
calc VE is in one, and actual table VE used is in another.  They usually
stay 
quite close.

Scot Sealander
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