I must stress that this is not anything I am certain of and this will get a bit technical. My asumptions here were started by this thread.
LFS's FF, albiet recongised as extremely good, has its downside - people claim that they cannot feel understeer. I have an idea as to why. The forces on the steering column are caused by the fact that the force centeroid (if you were to replace all the forces created by each bit of the contact patch with a single pair of forces - one longitudinal and one lateral - the point where you place these forces is called the force centeroid) is not at the wheel center. It is behind it in most cases. As such, when you turn the wheel and create a side force, this side force creates a torque onto the wheel which you feel in the steering column. This force centeroid moves around with lateral and longitudinal slip. Sometimes it is also to the side of the center of the wheel, meaning that if you had a longitudinal force, it would also influence aligning torque. If you look at a diagram of these forces, you can see that pressing the throttle in an understeer condition in a front wheel drive would make the wheel lighter.
I was testing if this is present on feel with the XF GTR on the Autocross earlier. It doesn't feel like there's a difference in FF between when you are turning and accelerating and when you are just turning. Obviously, I don't know how the LFS FF model works but I'd imagine it is based on these principles.
LFS's FF, albiet recongised as extremely good, has its downside - people claim that they cannot feel understeer. I have an idea as to why. The forces on the steering column are caused by the fact that the force centeroid (if you were to replace all the forces created by each bit of the contact patch with a single pair of forces - one longitudinal and one lateral - the point where you place these forces is called the force centeroid) is not at the wheel center. It is behind it in most cases. As such, when you turn the wheel and create a side force, this side force creates a torque onto the wheel which you feel in the steering column. This force centeroid moves around with lateral and longitudinal slip. Sometimes it is also to the side of the center of the wheel, meaning that if you had a longitudinal force, it would also influence aligning torque. If you look at a diagram of these forces, you can see that pressing the throttle in an understeer condition in a front wheel drive would make the wheel lighter.
I was testing if this is present on feel with the XF GTR on the Autocross earlier. It doesn't feel like there's a difference in FF between when you are turning and accelerating and when you are just turning. Obviously, I don't know how the LFS FF model works but I'd imagine it is based on these principles.