Quote:
Originally Posted by stlrj
High caster values will contribute to understeer by reducing tire contact patch with additional negative camber at tight slow corners where the steering wheel is turned to it's maximum. At the same time steering effort is increased as the suspension struggles to bring the negative camber back to a more neutral position.
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I was speaking of moderate to high cornering loads. The lateral acceleration will cause greater camber change in the opposite direction of the way that caster adds a little (good) camber so the contact patch should be better than with zero caster.
The tilting/lifting of the car due to caster combined with high positive scrub radius will be in the same direction as the lateral inertial reaction force, so there should be little increased effort in the steering wheel due to this aspect in isolation. The contact patch will, however, be made worse in the high scrub + high caster situation. Think of the tilting feedback during cornering on the steering wheel as the effort needed to push a bowling ball off the edge of a hill.
There will be more effort, though because the caster causes trail, and by increasing the slip angle you generate a lateral force at the end of that trail and cause a greater moment arm, which causes negative feedback wanting to decrease the slip angle (so turn the wheel opposite the way you are trying to turn it).