if you have one four inch exhaust with a fan, and a four inch intake with no fan, wouldn't you think it's restrictive?
It is hard to manage, but it could be a part of an issue . You can also waste alot of energy trying to pull air that air is restricted
furthermore if you are trying to get the best efficiency from your fans, you want an unrestricted intake (that means by rule of thumb 3x the area of your exhaust roughly, depending on CFM's) and to limit bends. It is hard to light trap in this situation but to combat heat you may want to just do a few tests on changing your ventilation technique to overcome this issue.
another way to check if your ventilation isnt the problem is simply an in-the-tent temperature and out of the tent temp.
if the two temps are very different you will know u have a venting issue
now that i've posted this and read back the temp of the room is 10 deg hotter than the tent. It is definately a tent ventilation issue and not the room its in ventilation issue.
I would tweak your venting setup man