adjustable rear suspension

adjustable rear suspension

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brownspeed

Original Poster:

743 posts

132 months

Sunday 23rd March 2014
quotequote all
G`Day,
Just picked up my latest project; the rear wheels are all over the place, and nervous as hell to drive. Just visually, massive camber and I think they toe out.
Look to have adjusters o the rear subframe around the grease point area; obviously I don't have any literature on these but have seen adjuster brackets for sale.
has anyone any experience in setting these up?
helpful answers gratefully received.

Cooperman

4,428 posts

251 months

Monday 24th March 2014
quotequote all
The settings of the rear suspension is probably the most critical area in terms of road holding and general handling.
For road use set the rear wheels to:

Toe-in: 1 mm to 2 mm
Camber: Zero to 0.5 degrees negative.

Make sure the front & rear are symmetrical with the front.

Then set the front to 1 mm toe-out. If you have adjustable length front tie-bars set the caster to 3 to 3.5 degrees.

I hope this helps.

annodomini2

6,867 posts

252 months

Monday 24th March 2014
quotequote all
Also depends on the quality of the adjusters as the cheap ones have a habit of moving.

Cooperman

4,428 posts

251 months

Monday 24th March 2014
quotequote all
I won't use the adjustable rear brackets. I always set mine by shimming and/or filing the hole in the end of the radius arm retaining bracket then welding a large washer on to hold the settings.

FWDRacer

3,564 posts

225 months

Tuesday 25th March 2014
quotequote all
Once set up - for road use mig weld and tack the brackets in place.

brownspeed

Original Poster:

743 posts

132 months

Monday 7th April 2014
quotequote all
Sooooo...
i've got the cambers more or less right, now the bloody rear tracking is out.
NS= toe out, OS= toe in!!
can't see any obvious adjustments to be made.
aside from shimming the subframe; any ideas??

FWDRacer

3,564 posts

225 months

Tuesday 8th April 2014
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Is the NS radius arm bent? Genuine question.


brownspeed

Original Poster:

743 posts

132 months

Tuesday 8th April 2014
quotequote all
FWDRacer said:
Is the NS radius arm bent? Genuine question.
OH! never thought of that. Good idea!
If it is- it's not obvious.
Any hints on how best to check to rule it out?

FWDRacer

3,564 posts

225 months

Wednesday 9th April 2014
quotequote all
Toe in is the factory default condition. A rear arm towing out is unusual. Make sure there are no shims between the subframe and radius arm bracket, occasionally shims are put on race minis to rpromote toe out and to help turn in. Unlikely to be on a road car TBH. If there are any shims present, remove them.

If you have access to another NS arm, use it as surrogate and checks dimensions.

Edited by FWDRacer on Thursday 10th April 08:33

Cooperman

4,428 posts

251 months

Wednesday 9th April 2014
quotequote all
I have had a situation where the toe-in on the rear was correct, but the front to rear alignment was out and the car was going slightly 'crabwise'.
So I added shims to one side and filed the hole into a slot on the other, welding a large washer on to hold the setting once it was correct.
By jacking the car up and removing the front wheels you can put long straight edges against each rear wheel and see where the inside edge of the straight edge intersects the front suspension arms. Measure from the inner end of the lower arm to the edge of the straight edge. It should be at the same position on both sides.
It is actually easier than it sounds.

brownspeed

Original Poster:

743 posts

132 months

Thursday 10th April 2014
quotequote all
Many thanks Gentlemen, i shall try this when i have a spare moment