How to apply real or fake physics to an actor along a spline without event tick ?

So the question is in the title, I don’t have any issues or anything I’m just trying to brainstorm how a system like this would work.

For context I’m working on a game project similar to Planet Coaster or NoLimits 2, and I need realistic coaster physics… So I would need my coaster trains to follow a path created by the player using physic properties like gravity, friction and whatnot, a bonus would be to calculate the g forces but that’s something I have to research later…

Right now I would just like to know how you guys would do this kind of thing and maybe give me hints about how to achieve this. I’m precisely asking something that doesn’t involve the Event TIck since I already have a full working system with gravity and friction using the Event Tick but if I have more than a dozen trains it severly lags the game, so using the Event TIck is not a valid option (unless it can be optimized).

So here you go, hope we will end by finding something together!