As far as I know there isn't any set up guide for Raceroom but there are some for other games.
Please find one:
https://gridmotorsports.com/forum/league/723889049/595195175/rfactor-f1-setup-guide.pdf
Advises can be applied to RRE as well (even if I have some doubts regarding several items, as camber for instance) Furthermore, set up possibilities are limited in RRE.
Personnally I proceeded like that for GT Master. Standard set up is not that bad and I didn't make too much changes.
Furthermore I'm not that fast and I don't rely to my feeling totally. And without temp/brakes temp and Motec it's difficult for me to define fine set up.
So, this is how I proceeded with GT Master:
1) sort out brakes lock issue: increase power to 100% and change bias. By the way, during race, when tires begin to wear, I'm sometimes obliged to modify it.
2) Sort out understeering (usual disease in GT cars, also valid in real life)
- Height: Standard heigth is quite high to my eyes: I reduced front more than rear. I keep 1,2cm gap instead 1cm. With that, I provide what we name "pitch" in motorsport (in French at least). Usually I'm around 7,5 front and 8,7rear.
- Rolling bar: Soften front and stiffen rear. But be carefull not to soft front too much, otherwise you mayhave troubles in slow corners. Usually I'm around 160 front and 40 rear.
3) Others:
- Usually I increase the bump to 8 front and rear and let the rebound at 6
- Camber: I just increase to 3,1 front. Normally, putting more is supposed to provide some benefits in curves but here I only noticed braking troubles.
- Wing: in fast tracks, I decrease rear but basic 11 is good.