In reply to Cloud9...68 :
Yeah, 20% might be a good number for GT car enjoyment at home.
Here's the final turn at sebring in a P2 car for reference: Sebring
Steering torque in a real car is all determined by the upright geometry, rack geometry, alignment settings and the track surface... Then you can add an insulative layer of power steering on top of that, and significantly reduce the driver forces felt. But the steering torques coming through the system are still there, when taking a curb, or going over a rough section of track. You could try to hold the steering wheel steady with all your might, but it will still bounce around a little bit.
That said, you don't need to worry about that stuff in sim racing, just mess with the settings for a couple minutes to figure out what you like once you have a setup. Each sim is a little different, each wheel system is a little different, and each person's preferences will be a little different.
As for motion rigs: It isn't that the system would have to be large and heavy and expensive to "truly replicate the g-forces in an actual race car". There is no possible way to get the correct forces in a stationary yawing, pitching, rolling chair. It is physically impossible. Think about this: you have 1 G to work with. You are sitting in a chair now (or standing) and experiencing 1 G downwards. We could strap you in a chair and roll it 90* to the right, and you would be experiencing 1 G to the right side of your body, kind of like you were in a steady left hand corner on 300 tw street tires. Except that to get there, we had to roll you, which you would feel, and that in itself would be quite a different experience to a car, where the lateral forces build very quickly with just a little bit of yaw.
So think about a slalom next: in a car, there's a little bit of yaw, a little outwards roll, and a bunch of lateral G forces, left, right, left, right. How do you replicate those lateral Gs with an expensive motion rig? You roll the driver left and right and left etc... except that the rig needs to roll the driver from full left to full right as quickly as you turn the steering wheel from left to right to get through the slalom.. Those will be some pretty high roll rates, and I think it's likely that your inner ear will know something weird is happening, even if the visuals are good. Likewise, you can't really get the yaw rates correct in the motion sim, because you need the available motion to get the lateral forces.... and any yaw turns those lateral forces into partial longitudinal forces if the chair is rolled on its side, so you'd feel as if you were braking or accelerating instead of yawing...
We can keep going with scenarios like this for a long time, just try thinking about them on your own and you'll begin to realize the full motion rotating chair isn't really a great substitute for driving a car around. I haven't tried one, but I'm inclined to think that I'd rather have no motion, than bad motion which has some lag from the inputs (because the actuators can't keep up with the speeds required) and weird rotation rates that don't replicate what you'd experience in a car.
Prototype Motion Sim
That all said, I don't 'see why a couple actuators with limited motion couldn't provide more tactile feedback to the driver: The track is bumpy here, you hit that curb, you caught that slide etc... Skip to 51 minutes to see the expensive chair shaker thing in action.
Sim Racing Garage D-Box 440i Review
You can add and modify your sim setup over time though. No need to start with a full motion rig. Get a good wheel and a rigid base to start with and see if you like it.
