[wizard]

Everything you said about steering effort etc is true.

As far as lock to lock, let me take an educated guess here.

Regardless of ratio, the rack will have to have a certain amount of travel to accomodate the steering geomotry. With a higher ratio (easier effort), you would have to turn the steering wheel farther in order to to move the rack the same distance. And visa-versa. It's the same concept as pulley ratios except that rotating motion is being transfered to linear motion.

I've actually done something similar at work with a motor turning a gear to move a linear shaft. We used a high ratio which translated to finer control on positioning the shaft and it also meant we could use a smaller motor, ie. less torque load on the motor or in human terms, less effort in turning the wheel.

As in all things life, there has to be some compromise.

Good luck in your decision.