I've played FAF on numerous laptops and they all have the same problem: downclocking due to heat or excessive power usage. In turn, the sim rate just drops and even on Seton's you become the reason why the game is running at -1 or -2 without that much going on. When you perform underclocking and / or using a fan pad to cool it down as much as you can then you are merely delaying the problem.
If I had the money I'd just buy a small computer to play FAF on .