ai are predictable, in sim racing ai, you just find their line and not use it for passing...oddly enough when track makers make the ai racing lines they seldom actually take the best line, another odd thing about sim racing content...
It's two hours, not two laps, so there is plenty of time to be patient. Everytime I get in a hurry bad things happen...whether that be because I cause it or because I forget that ai is dumb. AI is dumb, remembering that can save you lots of headaches...in road racing like Tigg said, you protect your car at all cost. Let them go, back off, don't push bad situations, give them their line because they do not see you, for the most part.