my guess is either the VTEC timing on the P72 is way off, or its disabled.

if VTEC engages either really low or really high, it wont have as pronounced of an effect.

the P72 (B18C ECU) may also be a little lean for the 2.2 going into VTEC, so less gas = less power = less "hearing/feeling" VTEC...

just a guess tho, im no ECU genius