are you guys saying that your vehicle runs better in a) cooler weather? b) under normal operating temp? there is a big diffrence in both. all cars run better with colder air since it is denser which means you can pack more air in the same amount of space. more air equals more fuel (o2 compensates) hence the car feels quicker. all cars feel quicker this way...or should i say most cars. (lol das shmoo)

if you are saying the other way...under operating temp......first off....vtec shoudlnt work so the car should feel slower. if you have a vtec controller then this sint the problem. but maybe the motor is cold meaning your intake is taking in the colder air (see above) when your car warms up...then your intake is now surrounded by hot explosive air.

if you wnat your motor cold....really cold......drill a small hole through your thermostat. you wont have heat since heat works off of heat from your motor. also you could try to cool down under hood temps by rasing the rear end of your hood with spacers or washers. a cheap mans way of a "hood vent"