It may be a good investment in our future to collect some cash and buy you a proper wheel Cameni.
Good FFB is generated from the geometry of the steering components of a car. Specifically the steering links.
Best shown on the entire internet by this RC car and the Brown tubes. They are in charge of pushing the Yolkes the wheels are attatched to left and right to steer the car.
Some description of forces would be...
If sitting perfectly still and trying to turn the steering wheel with proper FFB you would feel resistance as you are trying to turn static rubber wheels against pavement (or grass or sand) and that resistance would differ based on the materials the tire was on.
As the car begins to roll forward the static resistance would quickly fall away and be taken over by the cars suspension CASTER.
This is the vertical angle the wheel is dragged behind the steering axis. You would probably know it better from a shopping cart wheel.
That geometry tries to force the front wheels of the car strait. Therefore the Steering wheel will have the force pulling it to the center. The faster you move the stronger the force trying to straiten the wheels.
Bumps and gradient changes while driving would have the FFB wheel pulling and jerking. Usually a small amount but with off-roading as severe as outerra I could imagine some more severe jerking..
My favorite FFB effect comes in the form of driving WAY too fast over a crest of a hill. If the wheels have less pressure on them making contact with the road the FFB will go light or even completely loose as your wheels leave the ground. This is usually followed by a sharp return to center as the weight of the car is magnified from falling and the front end smashes down to the surface again.
Also locking your front brakes from braking too hard has the effect of removing the return to center feel and replacing it with just neutral shaking as a rolling wheel that is no longer rolling cant use any steering geometry. It just drags along the ground.
I may come back and edit this as this post might be the most important post I have ever written. No Joke.