I own an S14, & got around to gauging bumpsteer on the front end, i have read that when adjusting, the goal is to have, as close to zero bumpsteer as possible, i was gauging one corner & my readings at 1 inch of bump is .035 toe out, & as i continue to bump to inch # 2 it continues to toe out to .100, then at the first inch of droop it is .020 toe out, & rises to .080 of toe out on the 2nd inch of droop; this is the best i could get it.

This is the only car i have bumpsteer gauged & was wondering if this is what is expected on an S-Chassis veh. i will list the front suspension mods i have, for reference-

IKEYA formula front lower cont.arms/tension rods; lower cont. arm length set to factory arm length. SPL parts outer tie rods/Z32 inners

GroundControl camber/caster plates (i am using the caster feature on the plates to adjust caster in a manner so as to maintain the wheel centered in wheel well) adding lots of caster via tension rods pushes wheel towards front of fender well, limiting clearance. 

AST 5100/ dampners, Progress swaybar, Nismo power brace, 17x8 12offset front wheels

My static front settings are 8deg. pos. caster, 1.5deg. neg. camber & 1/16 total toe in, my static height is about an 1.5- 1.75 inch lower than stock so i am not slammed by any means.

Are my results due to the extra caster i have added which adds camber gain; which i think makes the toe change more, for a given movement. In the service manual nominal caster is 6.75deg & max is 7.50deg. (decimal degree).

I would appreciate some input

since on the subject, i had re-read the "Ultimate suspension part 8" article about steering angle inclination & you make mention RWD veh. usually run 3/4 - 3'' of scrub radius, also it recommends running O.E. scrub radius if possible, do you know what S-chassis scrub is stock? or do you recommend a particular value? (street car/occassional roadcourse use) At my last job i aligned my car & the SAI measured by the HUNTER align machine is 15.5deg. left side 15.7deg. right side (this is in decimal degree) max as per FSM is 14.4deg. does this value provide any insight?

As mentioned in my previous post, i kept the Ikeya front lower cont. arm lengths as the stock lower cont. arm lengths. Is this O.K. considering the lower balljoint is spaced down?

I will say for the years i have had this setup, & being that i am an amateur driver i have not felt anything adverse in the handling of the veh. in reference to scrub radius.

The only thing i have noticed for those whom have driven on the 405N. freeway here in L.A. when driving over the hill & barrelling down on the left lanes the road is very uneven  the veh. will feel twitchy & will give a sense of instability, which is why i deciced to bumpsteer the front & rear of veh. among the the perf. handling benefits this may provide.

I should know the stock scrub radius of an S13 but i DON'T, hahaha.  We have about 2.8" in our car.  You will notice a lot of scrub radius as not too good turn in and a lot of senstivity to toe changes and split mu traction.  I think when it gets stupid like more than 4 inches it gets obviously bad.

I like running longer front LCA's for less scrub and a wider front track, adjusting camber at the spindle.  Of course that means wider fenders