I don't know have I permission to give you some advises or not, but let me tell you something about how to set up your car to let you to be as faster as your driving skills allow you to be.
1. Wings.
Set up your front and rear wings. It's very bad when RW is much less than FW. You'll get a lot of oversteering right up to destroy your car. But when RF is much more than FW isn't good too. Have balance between them.
And at fast tracks(Albert-Park, Shanghai, SPA, Monza, Brazil) use low downforce for both you wings. At slow tracks(Monte-Carlo, Youngam) use high downforce right up to 11/11.
2. Gearbox.
You have to set up your gears right after your wings. First of all set up your 7th gear. Engine must reach max.revs. at the end of the longest straight. If 7th gear is too short, engine will reach max.revs. very early and your speed for example will be 175 mph, when you could speed up to 185 mph. If 7th gear is too long, dynamic of engine accelerating will be worth and you won't be able to reach max speed as fast as you can(end of longest straight).
Then 1st gear. Set it up to make steering in slowest turn effectivly. Car must go through slowest turn at max.revs. Then, just then you can set up others gear. And never make big difference between adjacent gears not to allow revs. to go down a lot.
3. Brakes.
When you look at track info you can see how brakes wear at current track. For example Albert-Park has high level of brake wearing, so set pressure to low. If wear is low, set it to medium or high.
I don't know about others, but I never shift balance to rear wheels. First of all when you pull up car, center of gravity shifts to front dramatically. It means that front wheels must pull up more effective than rear. Second: if balance shifts to rear wheels you have good chance to make them blocked. They blocked and lost grip with tar. you start to whirl around your pin(if you played rFactor you know what I mean).
4. Springs.
It's easy to understand. Braking goes much more effectivly than acceleration. So FSS must be always higher than RSS. At fast tracks use more stiff spring both rear and front(but front more than rear). At slow tracks set them to soft.
5. Clearence.
It's hard to explain. It's hard for me to explain it in Russian, how can I explain it for you in English. I just can say that lowest point of rear wheels must be always higher than highest point of front wheels.
6. Anti-roll bar.
It's hard to explain, because of I don't remember about it.
7. Camber/Toe.
Camber.
Distance between lowest points of front wheels must be a little more than distance between highest points of front wheels to let car to turn more effectivly.
Not same with rear wheels.
Toe. I'm tired.
Well, I hope it will help you. but take it in mind, it's just a game. You can set FW to 11 and RW to 1 and you'll set fastest lap. But I always use set ups like I just wrote. Goodbye.
