Hey mate,just head into options,it is a little square tab with what looks like a cog on it,should be on the left hand side of the gt life home page,once in there,scroll down and you will see options and click on that,then scroll down to steering controllers,and you will see an option that says steering settings,click on that than adjust away
I suggest trying all options,so you can see what you prefer,from my experience i found 1 to give best force feed back,from what i noticed the higher the the number,the more it puts a centre spring on the wheel drowning out some ffb effects.
Hope i was helpful and enjoy