Rfactor is very weird in its handling model. I think that comes down to each mod individually. So far the best one I have found, is the MMG F1 2007 mod. That just seems to be the closest to what I can imagine an F1 car being like.
A lot of the others, the cars just seem unnessicarily twitchy. The FsOne mod is really good, with some nice differances in cars, the Brawn and Red bulls are by far the easiest to drive, the ferrari is very twitchy under braking.
Do you use a Wheel and Pedals or a pad?
Also what settings do you have on? Like Traction control, damage? braking and steering assistance and so on.
My basic way of setups, I first of all go into the fuel and set it down to 10 litres, so you get an idea of the car at low fuel, I'll then go into the sliders menu, set the speed/accel to slightly towards acceleration, Then I'll have the downforce again slightly towards speed, and the car set slightly to understeer and also softer rather than harder on the ride.
This will give you a good base, do a couple of laps, see where your speed is at the end of the tracks longest straight, if you are not hitting the predicted top speed in setup menu, then move the gearing towards acceleration, no point having a top speed of 200mph when you can only hit 190mph. Same with the downforce, if your finding the car going straight on in the corners, just add a little more to it. It takes time but once you get it right it feels good.
