Hi ,I´ve a Logitech Wingman Formula Force GP,I´m not sure if it´s exactly the same that you say,,but in my case the configuration is very easy,,in Gp3 or in Gp3-2000,,I´ve the same values.,,
In the max lock 20deg,,,in reduce with car speed 75%,,,and the rest of values as it comes from the original setup,,,
I play without steering help (F8),,,and with the calibration of force feedback at maximum in all the values 150%,,(this calibration are putting in the controller calibration of your steering wheel,,not in the game).
That´s all,,with this calibration I have a very good sensation in driving,quite realistic,,I hope it will be good for you too.