my 94 vtir always runs cold, have never noticed less powerful vtec, i think its just the car ...when i had to change the radiator and bleeding it etc it took forever for it to heat up and the fan to even turn on...mechanic sitting there getting frustrated waiting...i'm assuming it doesnt take that long for other cars! Runs even colder at night with the cold air and sounds 10 x better when vtec kicks in i say.