Originally Posted by Equilibrium Tuning
[...] a change in VE could still result in a shift in a/f. This is because VE defines how efficiently the engine uses the air that it consumes. If you increase VE and keep all other parameters consistent (including airflow), you will inherently see a shift in the a/f.
You define VE very differently than me and the rest of the world. That sounds more like a definition of BSFC (or BS(Air)C, really).
But your explanation still doesn't make sense. If the MAF sensor tells the ECU that the engine is pulling in (for example) 100 grams per second, and if the ECU wants an 11:1 AFR, it's going to inject fuel at a rate of 9 grams per second. Why would changing VE (per your definition or everyone else's) change the AFR?
It doesn't change change the ECU's target AFR, it doesn't change the air flow, it doesn't change the fuel flow.... so why would it change the air-fuel ratio?