Roll Center design theory

[dennis68]

OK, here is the scoop. As many know I am on....limited funds (limited by my kids and wife, my W2 shows I should be a damn millionaire-where the hell is all the money)? I thought about this a long time and evaluated all the different possibilities. Buying a pair of 1 off custom spindles built exactly to my spec for under 500 bucks is a way better use of funds than trying to cobble together something that may or may not work.

The only problem is that the steering arm and ball joint tapers are not negotiable, they have a jig and it cuts the taper and you have to find ball joints to fit; small trade off in my opinion.

After enough hours in front of this damn LCD to make my eyes jump out of my head I came to a few conclusions;
1) No matter what you do to the stock spindle it will never be ideal
2) No matter what you do an F or B spindle it is even worse than stock
3) Relocating control arms is feasible but spindles require much less work and with relocating all of the pivot points that leaves a great deal of room for error.
4) Katz is a great guy and I'm grateful for his advice and time over the last month.
5) My elco is gonna whoop ass at the track……let the smack talkin’ commence!!!

Wally, I'm pretty sure the B spindles are only an inch taller, maybe 1.25". Mine are 10.50, that’s about 3" taller than stock.
110", I wish. My FVSA is under the magic 70" mark but scrub is under 2" and bump steer is almost 0 (.026" at 2.00" of dive) so I'm not terribly worried about the violent change, again a trade off for something else. I suppose if I were going to do a lot of high speed runs (ala Nevada style) I would be more concerned running that short of an FVSA but for street driving I don't mind the stiffness and most of tracks i will visit are nicely paved.

If I had to do this all over again I might have just gone with tall ball joints upper and lower, no on second thought I wouldn’t only because I like to be different. Using the stock spindles with tall ball joints is a huge improvement over the typical “tall” spindle conversion.

Good luck, I’ll post pics of my spindles when they show up.