...the steering rack in my car is 3.25 turns lock to lock....Speedway sell a Mustang II rack, however, they say it is also 3.24(or 3.5) turns.... am trying to keep the same mounting spots....anyone know of a rack that is a bit quicker?
Speedway do have a small 'doubler' the 'halves' the ratio, but that may be a bit too quick?
I don't think the turns lock to lock is the important thing. I the actual ratio between the pinion and rack gears is what you need to know.
The lock to lock, the distance the rack moves and the length of the steering arm on the upright from the "kingpin" line to the steering link mounting point are the important things in determining the overall steering ratio.
I had a similar problem but I didn't change the R&P. I changed the steering link mounting point on the steering arm. As long as you have too many turns lock to lock this method should work. In fact when you get done you have to limit the lock to lock turns to not have the tires turn so far that they or parts of the suspension start hitting things.
I changed my overall steering ratio from 3-1/8 turns to 2 turns by shorting the steering arms when I corrected my bump steer etc. And the 2 turns even decreased the turning radius compared to the 3-1/8 turns.
This is what the RX-7 steering arms look like (both arms positioned to show the top and bottom) with the original and new steering link mounting holes. The two holes at the top of the arms are the mounting holes for the steering links.
Yes, the angle that the steering link meets the steering arm will change. In my case the angle got more better not more worser.
This link will take you to my website where I show what/why I did this,http://dmr-architect.com/%7Elocouki/bump-steer.html