I normally just change steering lock, fuel and wing and then do minimum 5 laps just to see how the car handels. I then change gear ratio's and tyre pressures and go out again and do not less than five laps to check tyre heat and gears. Once this is done I try do as many laps as possible and make slight changes to the suspention as I go along and at the same time I am learning the track to. Knowing the track is where you make up the most time.
for me its a combo of practice, knowledge of the track, setup and driving style. i'm a smooth driver so the setup that i come up with will be different then a driver that is agressive with the car. like Bram said the more practice you'll get on a track with the same setup thats where you'll gain time the setup itself will not give you much more.
I'm with Bram on this one, setup will only gain you tenths, practice laps will give you seconds. Once you work out your driving style and what, in the setup of the car, makes it more comfortable then minor track specific setup tweaks can only ever give you tenths.
All my cars end up fitting my style, push hard/go slow. This works for me most of the time. When In trouble, I pick someone elses setup to see what they're doing and end up going only as fast as I go with my own!
Setup can make u faster but not to much.
Just try to push to the limit with a default setup and after u succeed to drive on a fast pace u can try using a setup.
Its true that a setup can make driving easier.
They can lessen the understeer and improve grip so that it will be much easier to handle the car.
The little tweaks the setups provide will make it possible to gain another second but not much more.
When u cant drive decent and fast laps on a track there is not much use of using a setup.