whats too hot and too cold for inlet temps

ive just checked my data log from a run

it gets up to 50s when at a stand still, heatsoak from the rad. then drops to low 40s-low30s
even hit 27degrees at one point. this was on a warm sunny day.

when is it too cold?
low 30s is best isnt it

i have a very large engine rad, with a very large charge cooler pre rad infront of it and no engine behind it, then have 2 pace charge coolers foor the boost.
i am going to raise the rear of the bonnet to let the heat out and get better airflow through the rads, but if its already cool enough theres no point.