That's for the V6

As previously stated, the F23 motor (with the exception of the F23A5 Non VTEC) has a VTEC engagement between 4700 & 4900RPM's. But, it depends upon Load, oil pressure & RPM's
The best way to tell is to get an aftermarket intake and listen for a more agressive sound from your engine during those RPM's. Remember, on the SOHC motors, VTEC is on the intake side only.