Well, I have a particular driving style (as I've said up above) I despise understeer for all that it's worth because it diminishes turn-in response, and belittles traction because of the wandering turning radius. Oversteer, on the other hand is far more manageable. Yes, it's a bit erratic and considerably clumsy but it can be controlled. Understeer can't be controlled without removing pressure from the accelerator, and essentially dry-steering the car into a forthright angle. Now, let's assume I'm taking that *thinks of random chassis* the VJM02 (Force India) around Monza or Suzuka, two tracks I know very, very well. The very first thing I'd do is take the car around for 1 or 2 laps to see how the default setup carries itself about before I start to narrow down any problems I'm having with the car. Once I go back to the garage I'll be begin tuning, and almost right the first thing I adjust is either aerodynamic downforce or ballast distribution.
Why would I adjust ballast?
To offset the natural understeer bias all of the cars seem to have. If you're thinking "Well, why not just increase toe, lower the ride height, etc..." you'd be right, but ballast shifts weight from one end (ideally there's a rear bias, but in-game has it being equally balanced, front and rear) of the vehicle to the other. With the front-heavy, or rear-heavy vehicle you'll obtain one of the following end results: A. With a front biased ballast the front end of the vehicle has more grip when cornering, and better turn-in (when paired with other settings) but risks the possibility of increasing understeer and/or plowing through corners - neither of which I've experienced as of yet. You're also leaving the rear end quite loose, so when entering a corner it's best to have the car straight before stomping the accelerator because if you're not careful the rear end will step out. B. With a rear biased ballast the rear end (as well as the front to some degree) exhibits greater stability when turning into corners. Although you can't really carry as much speed into chicanes or sweepers without running just a tad bit wide. For the most part, depending on the track and it's layout it's usually best to experiment with rear ballast first.
Toe-in and toe-out are two very important parameters when you want to improve turn-in response. To keep this short, greater values improve turn-in, lesser values inhibit turn-in by introducing mild understeer. Avoid extreme values. Camber improves tire adhesion (lateral grip) by tilting the wheel inward or outward, therefore increasing the surface area of the contact patch (better adhesion, more grip), or decreasing the surface area of the contact patch (the exact opposite). One thing worth remembering is camber is dynamic. Meaning it changes with every jounce of the suspension, so, it's best to read up on camber before adjusting it.
It is that last bit that I struggle with
