No formula really, it's just a process of 'test driving' the car and tweaking the settings where necessary. If it's flipping over or gripping too much (over steering) on a sharp bend, lower the friction settings slightly. Changing the suspension hardness/softness settings will also affect the over/under steering making it handle better (or worse). Testing and tweaking is your key to getting the car handling how you want it to. All of the settings mentioned in previous posts (ERP,CFM etc) should be tweaked and tested until you're happy with the setup.
The easiest method is to tweak only one setting at a time and see if you feel a difference in the handling, then make a note of the changes. Once you've experimented and listed the results from each setting change, you will have all the info needed to tweak it to perfection.
Each kind of car simulation would require totally different setups, for example F1, Touring Car, Rally etc...
It also depends on whether you're making a realistic simulation or an arcade style racing game.
A set of 'perfect' values doesn't exist, until you discover it through the above process, there's no shortcut.
After all, only you know how you want your car to handle ;)
The easiest method is to tweak only one setting at a time and see if you feel a difference in the handling, then make a note of the changes. Once you've experimented and listed the results from each setting change, you will have all the info needed to tweak it to perfection.
Each kind of car simulation would require totally different setups, for example F1, Touring Car, Rally etc...
It also depends on whether you're making a realistic simulation or an arcade style racing game.
A set of 'perfect' values doesn't exist, until you discover it through the above process, there's no shortcut.
After all, only you know how you want your car to handle ;)