OK I see that if the pitman arm on a box moves through 90 degrees - lock to lock and it takes 4 turns on a GT box to do this then to move the pitman arm 360 degrees ( 1 turn ) it would take 16 turns = 16 :1, the gear ratio.
I have only seen the spec of 16:1 given.
Do you know how the overall steering ratio of 21.7 :1 is calculated ?
I am curious thats all
Would it be how many turns on the steering wheel to move a road wheel 360 degrees ( if it could ?)