For finding that sweet spot, various setup guides that could help you to better uderstand positive and negative effects of every change.. :

 

Garage setup guide
Setup your car in 21 steps
Rfactor F1 setup guide
GTR enginiers handbook
GTR2 setup guide
Rfactor setup Matrix
- good one to start with

 

 

 

For analyzing data, and trying to figure out best way through corner, or to find setup flaws, you can use Motec program with data aqusition plugin in rfactor..

Motec program with data aqusition plugin, and with included good project file..
credit to our "racing father" - Zvjerko! :=

 

various motec guides:

Begginers guide to Motec
How to set suspension histogram
Motec guide
Tannerdog Motec guide