If you're seeing objects go through other objects or you have a low tickrate, you might want to increase the number of physics substeps. This breaks physics steps down into this many substeps. The default is 1 and works pretty good. Be aware that the number of physics ticks per second is going to be tickrate * substeps. So if you're ticking at 90 and you have SubSteps set to 1000 then you're going to do 90,000 steps per second. So be careful here.