I have had a b18a1 in my rex for the longest time but when i swapped it i messed the sensor so i just replaced it. i have a after market huge radiator and my car will hardly ever get half way warm. i know its fall. But is that normal? any info would be great.

 

The gauges are mostly dummy gauges. So it's quite normal for that to happen.

If you are really worried hook it up to a tuning program, test your thermo etc.