Quote:
The castor setting is non-adjustable on the 1200 and on many other McPherson strut cars.

This doesn't mean that you cannot change the castor. You can, by cutting the tension rod bushing and tightening it up again. Or by re-threading the tension rod so it can be shortened up.

After doing this, the aligment must be re-checked (that is, the toe-out setting).

Castor is what the trolley cart at the market has: The angle of the wheel hub, so that the wheel tracks straight when the cart is pushed ahead. Datsun 1200 has minimal castor for a light steering action. But it is too light and does not track well at highway speed. More castor than stock is better. 2-3 degrees has been recommended. 4 degrees is the most I've ever heard of for a 1200.

benny, pretty sure any modifications to the suspention components is pretty illegal...that said i ran rod ends on my control arms so that they could pivot where ever they wanted

going to change back to bushes as the rod ends wear out pretty quick with no covers over them

A very small %of the gains is (caster and its effects on camber of the outside wheel in a turn are obviously the 'big' factor) actually from relocating the front wheel centreline forward just a touch, which is not quite as good as but similar to moving some weight rearward, and getting a more advantageous polar moment of inertia (very basically the closer most of the weight is to the centre of gravity the quicker the car can turn in. If on the other hand you put just 10-20 kg of weight on a specially made bracket so that it sits say 1-2metres forward of the front axle centre line, it'd have great 'leverage' o the car and make it want to slide wide/understeer more significantly. Obviously nobody is suggesting really rigging up such a thing, but it's a good way to visualise why shifting (some, and of course it's all relative to a specific car) weight back a little, or moving the front wheels forward just a little bit can actually have some positive effects.

Short version of all that, if you can manage it, increase the caster by moving the bottom of the strut forward. If you can't the caster itself is the majority of the gains, so do it however you can manage it, you only miss out on a few % of the total gains.

Quote:

Good point, but wasn't sure if you can use them on a streeter....

The steering will be heavier on cornering due to the stub axle changing angle [arc] as the struts are turned left or right. for example sake the stub axle [tip & base] would be parallel with the road surface when travelling straight but as you turn the tip will move between say 0 degrees and +5 degrees as it moves in the arc left or right away from the road surface. Hope that makes sense.

from wiki

The pivot points of the steering are angled such that a line drawn through them intersects the road surface slightly ahead of the contact point of the wheel. The purpose of this is to provide a degree of self-centering for the steering - the wheel casters around so as to trail behind the axis of steering. This makes a car easier to drive and improves its directional stability (reducing its tendency to wander). Excessive caster angle will make the steering heavier and less responsive, although, in racing, large caster angles are used to improve camber gain in cornering. Caster angles over 10 degrees with radial tires are common. Power steering is usually necessary to overcome the jacking effect from the high caster angle.

http://en.wikipedia.org/wiki/Caster_angle

Benny, Have seen moded control arms with rod ends to eliminate the bushing problem. I went and bought some bits to do this, but as you know have given up on the 1200 for now.

a better explanation of castor would be great

thanks for the pic mik, ill do the same to mine
but whats all the stuff on your firewall?

1200 specific setup steps or castor explained better?

i kind of get it but im using more castor on threaded castor rods (not using the full threaded part currently).

also fine tuned with s13 cambet ops asdid piggy and boof by installing on a diagonal angle. reduces neg camber slightly on mine but castor did make car feel more stable bt with slightly increased steering effort (no drama in a 1200 and i thought gave more feel through the wheel too for input into a corner)

Dont worry about the gas stuff, just look at the angle of the camber top gives castor and camber adjustment this way