I use Real Head Motion and it's brilliant at stopping nausea in AC. https://www.assettocorsa.net/forum/index.php?threads/real-head-motion-1-0-2.4755/ In simple terms it acts like a variable slider between "locked to cockpit" and "locked to horizon" but it's actually much more. In reality your eyes do a lot of work to compensate for external motion and RHM emulates those movements for VR. Give it a try . Hit me up if you need any help setting it up.