Quote:
Originally Posted by phunt
The point of raised spindles is so you don’t have to change other settings or angles so the car suspension is like factory.
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again , not true
to keep things simple only consider the heights in 2 respects
1) wrt to the ground
2) wrt to the torsion bar center
the top of the shock is variable wrt to the ground but fixed wrt the torsion bar, i.e raise the t-bar and the top shock mount rises.
the rack height is variable wrt the ground and only variable wrt the t-bar by the thickness of what ever spacer is placed between it and it's cross bar fixture, max variance is ~10mm, i.e. a rack spacer increases the rack height wrt the t=bar and the ground
t-bar height is variable wrt the ground, via 2 mechanisms,
1) screw adjusters
2) axle height, a, variance
axle height, a, is variable wrt the ground only if the tire has a different static loaded tire height,
axle height wrt the t-bar varies if the spindle is raised (or lowered) on the lower strut, or if the t-bar screw adjusters are changed, this is a - b
so,
b is a measure of the height of the chassis above the ground
a - b is the difference between the axle height and the t-bar
which is also a measure of the difference in height between the axle and steering rack. This is the thing the factory engineers where most interested in back in the '60s. It is a measure of is how much bump steer(aka rolll steer) has been added to the car by lowering the t=bar height, b, via whatever mechanism.
stock a - b is 108+/-5mm
lower the car, by whatever method, to a - b of 148mm and you have increased the difference in rack height to axle height by 40mm, this means that to compensate and correct roll steer back to stock the steering knuckle must be lowered 40mm
an additional thing that happens when a - b is increased from 108mm is the steering effort also goes up because of the increased angularity of the steering arm.