44 replies to this topic

[76lxhatch]

^ Exactly, if the UC steering arms are used the ideal situation would be to use the upper control arms to match

[ls2lxhatch]

This picture taken by dangerous shows the three different arms side by side.





If you want to run UC caster then UC arms are the go.

I have a set of UC arms you can buy/borrow. Should be able to send them express post overnight for around $10-$15.

I also have a set of LX arms so if you want I can measure the difference between the two on the weekend. There is also a couple of different types of tie rod ends available. There is 9 mm difference in height between two of the brands I have and about 4 mm difference in the diameter of the head. The rod end you have looks similar to the lower but larger diameter of the two I have.

The Hoppers kit mounts the caliper at the rear. It would be worth swapping the stubs to see how you go with rear mounted calipers.

Edited by ls2lxhatch, 13 October 2011 - 10:31 PM.

[mick_in_oz]

Yup, follow, I think the caster available with the UC upper arm is another 2 or 3 deg over what you can get with the LH/LX arms, but don't think it was ever used that way on a road car, steering would be way to heavy with anything above 2 deg or so, i suspect the only difference in the real world was that the shims front to rear on the UC arm is similar rather than lots and little on the early arms.

[Toranamat69]

Irrespective of which top control arm, it is the castor setting that determines how high the steering tie rod is. as long as you can get the castor setting you want with LX top control arms the only difference to UC ones is the size of your shim stacks.

I am actually still running LX top control arms on mine and I run about 2.5 degrees positive castor which is where the UC's normally run from memory.

I reckon UPC are waiting for us to sort their brake system out so they can steal the idea for themselves so they can tell people how to actually fit their kits to Toranas hence why they are lingering around.

[76lxhatch]

It would be worth swapping the stubs to see how you go with rear mounted calipers.

If all else fails yes but if they are only 3mm from clearing I'd be trying the UC steering arms and a touch-up of the caliper first because there are other clearance issues to deal with when the stubs are swapped over (they can be dealt with but if they fit on the front that's preferable)

Yup, follow, I think the caster available with the UC upper arm is another 2 or 3 deg over what you can get with the LH/LX arms, but don't think it was ever used that way on a road car, steering would be way to heavy with anything above 2 deg or so, i suspect the only difference in the real world was that the shims front to rear on the UC arm is similar rather than lots and little on the early arms.

LH manual lists caster to be -2 to -1 at wheel alignment. Can't find a spec on UC but its definitely positive with the RTS, I would think that something similar to early Commodore (+0.5 to +2.5) would be about right for factory spec. So that would work out at at least 1.5 degrees difference. Steering isn't heavy with narrow 13" tyres

[mick_in_oz]

Thinking about the way the earlier Torana's have negative caster, this would put the smaller drop/offset steering arm from LH and LX lower and in the correct position (top forward, tierod end further down at the front) with the lower arm and have an effect on the amount of bump steer that is inherrant with the chosen parts. Now with the revised UC settings of positive caster this puts the steering arm up a lot at the front, presumably causeing lots of bump steer and thus the need for the revised UC steering arms with the extra drop/offset in them, closer to the A9X arm, looking at it like this it might appear that the differance was brought about by the revised alignment settings and nothing more.

My LX is very late with RTS and from memory the book (or so i was told) shows it as negative caster also, and it was always a pig at speed, untill it was changed to a good amount of positive caster.

[76lxhatch]

looking at it like this it might appear that the differance was brought about by the revised alignment settings and nothing more.

Between LH/LX and UC steering arms, yes. However to achieve the difference in alignment you need the UC upper control arms too

[mick_in_oz]

Cant see how the UC arm vs the LX arm with a different amount of shims, is any different? Both can be set up for, lets say +2.5 deg caster, just with a different shim stack on the LX arm...

[76lxhatch]

Eh? I don't know what prompted that comment Chopper, you've made a few comments recently where you seem to think I'm disagreeing with you when I'm not...

You simply can't get +2.5 degrees of caster from a standard LH front end without dangerous amounts of shims (and yes Chopper I'm agreeing with you here again)

[dattoman]

I have no idea why someone would even bother dealing with some people

[ls2lxhatch]

There are plenty of people in Perth, you just have to know where to look.

Heres one for a start.
http://www.brakefabr...swa.com.au/home

[dattoman]

He spoke to me
Then went to see Rodney
And decided not to use them

If I had a workshop and time I'd do it
But The place I'm working right now isn't the correct environment