Hi! I´ve been trying the Cammus C5 on iRacing for several weeks and these are my favourite settings for F4 and GT3 (two of the most popular cars)
GT3
F4
VERY IMPORTANT
What I do to decide how strong I need the FFB I change it for each car and each track by doing a complete lap, going to Black Box and setting the AUTO ffb as you can see on this picture
Once you have the AUTO clicked you must watch your F bar on iRacing to ensure your wheelbase is not clipping. You will notice the clipping when the bar goes red (for example on high kerbs or fast and long corners)
If you really love a high FFB feeling, it´s okay if the F bar goes red just occassionally (miliseconds) but the red bar must not be seen continuously during the whole fast corner.