Wheel Alignment Tips for Custom Cars : What is Caster in a Car Steering System?

wow! An expert on expertvillage!

I know that high rates of positive caster can become very negative caster when backing down a long driveway, so in that case I'd rather have more SAI than Caster.

Also, why is the effect of unequal SAI(a degree or more different from left to right) felt at LOWER speeds, as a pull, than at high speeds, as is the case with unequal caster or camber?

you have to be a little bit more specific on the question? depending on your vehicle measurements your SAI and your IA (included angle) should be equal or have 0.30 degress +/- left to right, for example if your IA is cool and you SAI is off and your camber/ caster is ok it could be that your upper/ lower pivot point are not located in the correct locations( or their bent)

Good explanation of caster!
Question: Which has more effect on straight-line stability and return from turns - Caster or SAI(Kingpin for you old-schoolers)?

Second Question: I know this is dependent on the type of car, but how do engineers know how much Caster and Steering-Axis-Inclination to design into its suspension? Some cars have conservative amounts of SAI and high caster, and others, vice-versa.