FC3S5
then in 900 degree mode on gt4, does that mean while going through a turn you will have to turn the wheel all the way to one side to get to the point where the tires are about to give way or is it gonna be like in a real car where you only need to turn the wheel a little bit? and what would happen if you tried to turn it past this point?
If you do not drive on the limit, and the drift angle of the tires is low or zero, then you turn the DFP like e.g. only 60° for the first RH corner in Tsukuba.
When you drive on the limit of adherence of the tyres, you will turn the steering wheel to the point where the tyres are about to give way, that's correct. That point is - on street tyres - at +/- 90° to 135° (I did not really measure this out, so it might be some ° wrong, but it's the order of magnitude). On slicks the angle is smaller.
When you go beyond this point, you get understeer il almost all cases, i.e. the front wheels loose grip, and you turn the DFP further without turning harder.
In one very particular case, there is a school example of oversteer : with the 2001 Mobil 1 NSX in the long RH corner halfway on Fuji. This car has so much downforce that it allows to go full throttle through that turn. While you are accelerating through the turn, you actually don't have to turn the DFP tighter. You even have to steer less tight with speed going up! For those with GT4P and an ARMax or AR2v2 it's definitely worth trying out!
Minnesota01R6
are you able to change it at all? I just don't see how you can use the paddle shift while arm-over-arming the wheel to take a sharp corner. [...] I think it would be unrealistic to ecpect us to be able to shift like that in GT4 with the DFP.
Unlike e.g. in Grand Prix Legends, it's impossible to change the steering ratio in GT4P. I think the reason you mention is exactly why there's a gear stick on the DFP. However, as far as I remember, I only had to use the stick in few occasions : mostly when I made a spin and have to manoeuvre back on the track
In "normal" conditions, the steering angle does not become so large that you can't use the paddles, even on street tyres.