Invest in hardware! Simracing is about speed right? So if you are driving fast but the images build up slow that is not really how we want it right? So just like in a lot of first person shooters, you want get your FPS (Frames Per Second) as high as possible. The more frames, the better the feeling while racing. Also if the frames are to low in for example a VR (Virtual Reality) setup you can get dizzy while playing your game.
Unfortunately hardware costs money, so more fps will cost you more money. If you do not want to spend that extra money you could also choose to lower your detail ingame to get that extra frame.
Alternatively you could choose for the console instead of the pc to play your game. The game developers will make you get the best out of the game on your type of console hardware.
So in a nutshell.. FPS is king!