jmassey is spot on. One thing you could try is turning on sub-stepping which will tick physics at a higher rate. In the settings you can control how small you want to make each sub-step so you can render at 30 but tick physics at 120, though this might be quite expensive.
If you go this route and want even more accuracy you’ll want to apply forces at the sub-step level. If you look at the vehicle code we actually do this, but the way we do it is not very extensible. There is a plan to make this a more generic system that you can plug into, but that won’t be in for a little while.