PM Mr S or check his setup thread. The setups are for a Mclaren but will get you started at least.
You will need to add more wing F & R, change gear ratios to suit, change brake bias to the rear a bit, soften F & R sway bars a bit, add more rear toe in as needed.
I find the Cosworth engine aggressive in power delivery, and just lacks front end bite/grip. It mirrors the real car by being a bit of a dog of a car.