Settings for DFP on GT5P?

[Goshin2568]

Hey guys. I have a DFP (upgrading pretty soon though) that I use for GT5P, but I can never get it to feel right. I've haven't tinkered with the settings too much, but everything I try has some major flaws. When the force feedback is too low, the steering just feels unrealistic and like it is trying to be smooth, but failing. Too high, and I let go of the wheel and it starts driving itself. I haven't driven too many cars, but my car dosen't do that when I let go of the wheel, not even past 80. So, I guess my question is, can someone give me the optimal settings for the wheel that makes it fun and realistic?