Can the Push to Pass be improved to be more realistic or is it a matter of what the game already has for its existing push to pass cars? I have a couple suggestions if it's possible to edit.
1. Reduce the cooldown from ~2 minutes between presses to something more reasonable like 30 seconds (I don't think there is any cooldown except maybe a quick recharge in real IndyCar). Currently, if a race is 40 minutes or less, you basically never run out of charges, it just comes down to when you use them on which parts of the track rather than when during each stint of the race.
2. I am personally ok with the 10 seconds of committed increase in power you can only use 20 times per race, but I believe realistically it is more like ERS/KERS that just doesn't recharge, so it ideally it would be a press and hold with a max of 20 seconds per lap or something and a maximum of 120/150s per race.