I am quite unexperienced with setups but I mainly go by this:
http://www.racedepartment.com/threads/the-21-steps-guide-from-gtr2.99873/
For me it's not really for the laptime but more about how you feel and connect with the car. The default setups are very good in assetto corsa so mostly you don't need to tweak much.
When going by the setup PDF I linked you have to know that toe, camber, loads etc don't influence the tire temperature that much in AC! Don't setup your car for the perfect tire temps. Set it up so that you feel connected with the car!
First: when you are more or less on the limit-> adjust the tire pressures! Try to have them all perfectly green. It's quite important in Assetto Corsa!
In general I will go through a setup like that:
First you have to be consistent and on the cars (or your) limit!
Then you adjust the gearing, you should be slightly below the rev limit on the fastest point on the track. Or better: at the PS - peak!
Then if you feel you have to shift on crucial points: adjust the single gears separately (like IN the Michael Schumacher S at Nürburgring. You don't want to shift in that!).
While you are doing that: adjust the tire pressures as said above. Really, it's important!
So we have done: gearing and pressures.
Now comes aerodynamic!
If you feel the car should be faster on the straights you can lower the downforce. If you want to be faster in the corners you raise it.
For me that's hard to figure out but just try it. Beware: downforce doesn't matter that much in slower turns!
A few examples: Le Mans, Nordschleife, monza go for low downforce. Barcelona, mugello and spielberg I go for higher downforce.
Now the general things are set up and you can adjust the handling.
General:
Understeer = hard front, soft rear
Oversteer = soft front, hard rear
If the car feels sluggish when turning in and you feel some overall wobble: stiffen the
springs. I did that in LMP1 at Le Mans!
If the car feels too bouncy: soften them (like on the Nordschleife).
I barely touch the springs but if you really can't connect to the car try to harden or soften them!
Then I mostly go for
toe,
damper and
anti-roll-bars.
Toe: it adjusts how fast the car will turn in. It's really only the turn in speed, traded for stability on straights. It doesn't really cause understeering or oversteering. It's just how quick the car will go for a turn.
Faster turning: toe out
Slower turning: toe in.
You will often see front toe out and rear toe in (look at the "car status" on the setup screen, not the slider it self!). That's kind of a mix for stability but quicker turn in!
Then I adjust the damper for understeering or oversteering. The damper are like inertia for the handling. So you turn in, the car starts to turn (toe setting) and then the weight shifts and the dampers "push against it".
Don't go for extreme settings here. You want more oversteering after the turn in? 2 clicks softer at the front and back on track.
I just do 2 clicks on every slider there is, so you don't get an imbalance between them!
If that's not enough go for 1 click harder at the rear and another one at the front.
If still not enough you can do the same for the springs.
Now we are completely into the turn. The car goes perfectly into a turn and feels good while turning.
Now the
ARBs come into play. If the car under- or oversteers in longer turns, like the Parabolica at Monza you adjust the ARBs.
Here you can go for extreme settings, just experiment with it.
When you go for really soft ARBs you will feel how the weight shifts and shifts... And shifts while cornering. If you go for max soft front ARB and max hard rear ARB you will feel how the car will go into a spin while turning and you can't do anything against it. Same for the opposite: the car will turn in nicely and then won't go around!
If the car feels good but loses grip on one axle in fast, long turns (Nordschleife has a lot of them) you can adjust the downforce!
Now we are mostly done with the setup but one thing is missing that's important!
The
differential!
If you feel like the car is spinning on corner exits and you can't do a thing against it no matter how carefully you apply the throttle:
lower the power diff setting! I often go for the lowest setting possible (need to be more sensitive in the right foot!).
And if the car feels too much on rails while braking: adjust the brake diff setting.
And if the car get's unstable when you lift the throttle or the brake: raise the preload.
I think I've said a lot of wrong things but I am still learning too and just shared my thoughts
And beware: every setting influences the others. You need to find a balance for them all
Long text, most is already said in the other guides but it's good to write that down. Had to do it a bit for my self
[written on phone]
PS: if you want to do a "setup session" we can do that! (Not as "official staff session" but as normal, casual drivers)
Doing a setup on your own is one thing. Talking about it in general another thing and working together on a specific track, discussing every setting and trying it with more than one person is what really brings you forward!