I was wondering myself why would I need to tune the VE table and I came across a write up on how to tune VE tables for LS1 engines and it said the following:
"So, if we have a
MAF, why do we have a VE table at all? One thing the VE table does is provide a
reference airmass calculation. The PCM uses this reference to compare the measured
airmass supplied by the MAF to so it can ensure that the MAF is operating correctly.
Also, while the MAF is accurate at measuring airmass that is entering the engine at a
constant rate, it is not at all accurate when the airmass is changing, like during throttle
transitions during normal driving. At these times, the PCM blends the MAF signal with
the airmass calculations derived by the VE table to provide accurate fueling. So, above
4000 RPM, or during steady MAP conditions, fueling is set using the airmass
measurement provided by the MAF alone. Under 4000 RPM, during unsteady MAP
conditions, fueling is set using the airmass measurement provided by the MAF, modified
by the airmass calculation derived from the VE table. Understanding the close interaction
between the MAF and VE table, it is easy to see why it is important that they both are
correct and working together."
