Self Centering - lack of

[Enoch]

Well today I took the bull by the naughty parts and made some blocks to lift my rack so the track rod ends were nearly level, set the wheels to toe out by about 5 degrees and pumped my tyres up to about 25psi. It does now self centre much better but still does not go all the way to centre. I will fiddle about a bit more but gut feel is that it would be ok for IVA as it is. The thing that seemed to make the biggest difference was lifting the rack to make the track rods at less of an angle. I think it's because the caster tries to make the wheels straight but the angle of the force on the rack was trying to push it down rather than back to centre. Anyways whatever it was it's heaps better now. I might try a bit more toe out to see if it is better or not, I will also experiment further with tyre pressures.
Best and all that,
Enoch

[mr henderson]

5 degrees sounds like a lot to me, what does that work out to in mm?

[AshG]

it should self centre at the proper settings which should be between 0 and half a degree of toe in.

the wording in the manual says it should show a degree of self centering above 10mph.

when they tested mine he put it on full lock at stand still and started speeding up. if the steering wheel moved and the car starts trying to come straight then that's fine for a pass.

[Big Vern]

Shouldn't need more than 1/2 degree toe in on any car. A little toe out may help for the test but 5 degrees

The problem is the book doesn't give the car hardly any caster so there's virtually no self steering.

Need's a revise of the lower front wishbone design to increase caster and thus more self centre, then the mushrooms could be put to the position they should be.....

BV.

[Trophy Blue]

I redesigned the Locost upper wishbones 7 years ago, to increase the self centring on Cortina knuckles.

I cannot understand why the Haynes design didn't do something similar to ovecome a known problem with Sierra knuckes.

[Enoch]

I had a further mess about today, if I now set the wheels to about 0 degrees toe it does still self centre but not as well as with a degree or two of toe out. Dialing in a bit of toe out makes a big difference. I also experimented with tyre pressures but got less marked results from that. To my mind it now complies with the IVA rule with it set so that handling should be Ok so I am a happy camper.
Thanks to all those that replied.
Enoch

[twinturbo]

My new garage service has just purchased traditional laser 2 wheel tracking equipment. Not new fangled 4 wheel computer programable stuff..

So They whould be able to set my tracking up nicely for me when I am done .

TT

[mr henderson]

Originally Posted by twinturbo

My new garage service has just purchased traditional laser 2 wheel tracking equipment. Not new fangled 4 wheel computer programable stuff..

So They whould be able to set my tracking up nicely for me when I am done .

TT

Traditional but with lasers? How traditional is that?

More to the point, I think 4 wheel alignment is superior, especially for this type of car.

[snapper]

[quote][Hi Snapper, which test center did you use? Did they expect it to centre all teh way or just show some centering effort?
Enoch
/QUOTE]
We went to Norwich from Essex, nearest test station since Chelmsford does not do IVA.
We had no self centring with 30psi, added some toe out(a hint from the tester) and it gave enough for him to be happy.did not need to see full centring just a noticeable unwind of the wheel when he let go.
Did you say you have the offset mushroom orientated forwards, we set it pointing to the wheel to get the correct angle on the ball joints