Mark 1 Upper Control Arm Upgrade ??

[ProfessorB]

FINALLY DONE. FINAL ANALYSIS:
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Well, the upgrade is finally completed and I put about 100 miles on the car today. VERY happy with the results. As was predicted by others, the car has indeed been transformed. The two major changes were a slower-ratio rack and upgraded SPC upper control arms (which in turn resulted in increased caster since they had more range of adjustment. I bought a camber/caster gauge and turn plates and set the aster and camber myself. Final settings was neg .5 camber (both sides) and caster was pos 9.9 on the left and pos 10 on the right. Try as I might (for HOURS) I could not get them perfectly matched. I did learn (as I progressed) to make smaller and smaller adjustments but even with small adjustments I was chasing my tail. In the end, I decided that one tenth of one degree was acceptable.
I did the tow-in last. Mostly because the continuous camber/caster adjustments change the tow-in...so I saved tow-in for last. I used the "string method". I had read up on DIY alignments and discovered that race teams prefer the string method over the laser method as a laser can lose calibration if dropped....but a string is always a string. I attached a 4 ft level to each rear wheel, using one inch spacers so that the level would touch the rear rim but not the rear tire. the reason i used the levels is to increase the length of the "straight" reference point and so increase the accuracy. Next I stretched string along each side of the car. I "towed in" each side of the car separately...keeping in mind I wanted each wheel to tow in HALF the chosen amount of total tow in. So each wheel was towed in 1/32, resulting in a TOTAL tow in of 1/16. I then checked and confirmed this with a tape measure across the tread.
Car has indeed been transformed. Some (most) will tell me it was the caster change and not the steering ratio change that made the difference. perhaps they are right. After all, I'm not on this website to teach...I'm on here to learn. There ARE some teachers on here but I'm not qualified to be one of them. All I'm doing here is sharing my experience. I got the car over 90 MPH with one hand on the wheel and feeling quite comfortable. I also took the car thru the original corner which gave me concerns to begin with, the corner I had "trouble" with. Happy to report I had no "twitchy" issues and I took the corner at a higher rate of speed. And in NO way is this now a "slower steering" car...it's still the quickest responding car I have ever driven so, in that respect, I'm glad for ALL the changes I did, including changing the rack, but I'm also happy it was suggested that I change the upper control arms.

[CraigS]

Excellent results. Your FFR is now similar to mine which was just fine. BTW, I now own a 19 STingray and the steering may be just a tad slower than the FFR was w/ the 3.0 turns rack so I think we are in good company.