I don't think the factory gauge is much chop BUT even if it's half accurate I find the temp goes up after some spirited driving, this was the same at 200kw, 250kw and now at 360kw (although it hasn't had a good run at this power yet)...
I will be going a bigger Radiator and Engine oil cooler when I start tracking the car a bit more.... Possibly a steer cooler too