Interesting, as I'm on the opposite end of that one. I've never found sensory overload to be a significant issue in anything I've flown/driven/ridden/raced (including motorcycles). The fastest stuff has required a session or three for my brain to come to grips with the rate of sensory input and get fully on top of it, but after that it's never been an issue and it normalizes to no longer being stimulating just for the sake of the thrill of speed. (Which isn't to say there isn't something fast enough to saturate my brain's ability to process my sensory inputs.) Rather, it's the competition and pursuit of excellence that keeps it interesting.
What I will say is that maintaining full situational awareness and keeping my racecraft sharp is more difficult in a sim, because the quantity and quality of the inputs just aren't as good as the real world.
Sims obviously aren't nearly as physically demanding (though a full-length grand prix will still leave me in a sweat by the end from concentration), but I find I have significantly more mental overhead in the real world as it's far more intuitive. And if the physical risk is a persistent stressor that takes attentional overhead while racing, then congrats, you're wired like a functioning human, not a racing driver!
What I will say is that maintaining full situational awareness and keeping my racecraft sharp is more difficult in a sim, because the quantity and quality of the inputs just aren't as good as the real world.
Sims obviously aren't nearly as physically demanding (though a full-length grand prix will still leave me in a sweat by the end from concentration), but I find I have significantly more mental overhead in the real world as it's far more intuitive. And if the physical risk is a persistent stressor that takes attentional overhead while racing, then congrats, you're wired like a functioning human, not a racing driver!