The setup is really straight forward for Racing Sims. Just follow the Oculus initial setup through their software and you'll be up and running in no time.
Things you should considering downloading.
- Content Manager for Assetto Corsa (allows you to free up more resources for higher graphic settings)
- Oculus Tray tools (Use the visual HUD: Performance to see how what your FPS are)
- Test, test and test some more until you get a balance between performance and visuals.
Project Cars 2, Dirt Rally and Assetto Corsa are what I generally race with. Having a huge preference to Assetto Corsa. For AC, I would test with the OEM cars first to get a baseline and then you can tweak with modded vehicles and tracks as they will have an impact on performance or can that is.
Race Sim Studio Cars that I loaded give a dip in FPS. Most of my settings are on High, but if you like I can share my settings based off my specs if you want an idea.
I personally do not like being in Asynchronous Spacewarp ASW as it fills the frames for any that were drop to maintain a level of play-ability. I'd rather have settings a bit lower to maintain a 90FPS as you can have longer sessions and won't feel nausea or at least less prone. This of course is subjective to the individuals.
lastly have fun and remember to listen to what your body is telling you otherwise you can get very sick, very quickly and that'll ruin your day.