rusty nuts
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| posted on 26/12/05 at 06:37 PM |
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Paul , I think it only needs to be seen to self center when tested . Got 4.5degrees on mine which seems to be OK . It doesn't self center as
well as a production car I find it fine. PS a screen don't really help !
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David Jenkins
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| posted on 26/12/05 at 07:05 PM |
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Paul,
Don't worry about it - all will be fine.
My SVA tester simply put the wheel to full lock, then started the car forwards - as long as the wheel started to turn forwards he was happy. This he
did both ways.
In reality the self-centering with a 22mm offset is noticeable in normal driving - if I release the wheel at speed it does tend towards a straight
(-ish) line.
David
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907
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| posted on 26/12/05 at 09:55 PM |
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I think I've put the bush brackets on the chassis to the book dims, within a mil or so.
The top bone has an offset of 22 mm.
This means the centres of the balls of the b/j's are now 26 mm out of line, giving a
caster angle of 7.1 deg. (if my trig is right)
Although you can just about let go of the wheel at say 40 mph, if you pull out of a
tee junction without hands on the wheel it won't straighten out, but would do a
full 180 deg turn. 
Is this what other peoples cars do ?
I have enough spares to make another set of top bones and if I can improve the
steering it's no hassle to do so. A couple of hours at the most.
Thanks for your input so far. It's much appreciated.
Paul G
(I've added to the diagram if this helps to explain)
 
Rescued attachment castor-angle-diagram2-s.jpg
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WIMMERA
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| posted on 26/12/05 at 10:16 PM |
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Paul
Have you checked for any tight spots in the steering mechanism, a tight bush in the column or the rack, ball joints etc any friction here has to be
overcome by the self centreing action, 7 degrees should be enough
Wimmera
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rusty nuts
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| posted on 27/12/05 at 08:50 AM |
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New ball joints tend to be a little tight and will ease with abit of use. Also tracking may be having an effect, excessive toe in/out ? when you get
the bodywork on the extra weight may have an effect. If you have any signs of self centering it's probably enough.
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907
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| posted on 28/12/05 at 10:07 AM |
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So the general consensus is that I have enough to pass SVA, so for now I'll leave it at that.
As some of you said, the b/j's may free up.
I'll put the spares in a safe place to gather a protective layer of dust, and use them if I have
to do some fine tuning at a later date. (If I can find them.  )
Thanks everyone for your help on this.
Cheers
Paul G
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andyps
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| posted on 4/1/06 at 05:10 PM |
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Are all the measurements on this applicable to a Sierra upright as well as a Cortina one?
I hope to get my wishbone mounting brackets fitted this weekend and may as well get them close to the right place for the castor adjustment, and
hopefully can stick with the bones I have (off an MK Indy).
Andy
An expert is someone who knows more and more about less and less
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blueshift
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| posted on 4/1/06 at 06:32 PM |
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Castor angle is all about the line through the balljoint centres. This is unaffected by the geometry of your upright, the castor angle will be the
same whether you use cortina or sierra.
Camber may be different however.. and there is an issue with the balljoint taper being at a funny angle in the top of the sierra upright which may
well require a redesigned wishbone so that the top balljoint has enough travel. There was an active thread about that recently.
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andyps
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| posted on 4/1/06 at 07:45 PM |
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I understand about the angles - I was actually considering the measurement in mm (or inches) as that would presumably vary if the sierra upright is a
different height to the cortina one.
Andy
An expert is someone who knows more and more about less and less
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blueshift
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| posted on 5/1/06 at 06:32 PM |
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ah, I think I see what you mean. good point, and I don't know.
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andyps
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| posted on 6/1/06 at 12:12 PM |
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quote:
Originally posted by blueshift
ah, I think I see what you mean. good point, and I don't know.
Does anyone??
Andy
An expert is someone who knows more and more about less and less
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.jpg)
