So I upped the bill and bought a 6" inline fan, then I noticed it was causing one of my 120mm fans to spin in reverse, it needed that much intake and I guess I just didn't have enough, made the intake hole twice as big and it's still sucking like a champion... So the passive airflow seems to be ok.. Last recorded temperature was 84 degrees but I'm testing now to see if that climbs anymore. getting closer and closer!