I have always had a difficult time getting the GMVE table in the E40 nailed down. I always had to multiply by %-half which took too long and even then it would end up overshooting. Doug (EC_Tune) gave me the idea of logging VE airflow and MAF airflow and plotting the difference against the VE table. Since I have my MAF dialed in pretty good and I run with the dynamic airflow disable RPM set to zero which disabled VE lookups, I decided to try it. I added VE Airflow to my table and created a custom PID for "VE Error" which is sort of like AFR Error except it is a percentage of how far off from the MAF flow the VE flow is. It goes like this:
([SENS.40]-[PID.2311])/[PID.2311]*100
Where SENS.40 is the Mass Air Flow (SAE) and PID.2311 is the VE airflow.
Then I set up a histogram to plot this custom PID against the primary VE table. Then you just copy and paste special, multiply by % the errors displayed in the histo.
I got some pretty decent error since I hadn't touched my VE since I installed my 100mm MAF and scaled my IFR to stay under the 12.2k Hz and 512 g/sec limits of the MAF table. I didn't try to hit the entire VE table, it was a drive to work so it's mostly in the lower MAP/RPM range but the result for the cells that I did hit was a very nice smooth VE table. I'll flash this for my drive home and see how closely the VE airflow matches.
I'm not familiiar with Bluecat's program because I don't have a VE equation, but I would imagine you could use the % errors you get from this the same as fuel trim or AFR error numbers to plug into his program to derive your VE constants. I donno.