Rear suspension adjustment

[alga]

One guy on a Lithuanian forum questioned the lack of toe adjustment on the rear wishbones. He referred to Rorty Locost IRS design as an example of suspension with adjustable rear toe.

What do you guys think? Will a typical DIY rear suspension to have a reasonably small toe angle?

[Talonmotorsport]

You could use the 'book' lower rear wishbones as they are and make eccentric (I think thats how it spelt ie off centre) top hat bushes to give you some small adjustment. This is some thing I've discussed a few times with people but am not sure if it would work with out having a rose joint on the top arm instead of using the current set up. I know the MX5 has this set up but then again it uses rubber bushes which have considerable more give than poly bushes or nylon. One trick to getting the brackets correct is to tack a bar across them down the length of the chassis about a meter long, and messure the gap between the chassis and bar. If the gap is even down the length of the bar then the brackets should be straight,make sense?

[GraemeWebb]

Originally Posted by alga

One guy on a Lithuanian forum questioned the lack of toe adjustment on the rear wishbones. He referred to Rorty Locost IRS design as an example of suspension with adjustable rear toe.

What do you guys think? Will a typical DIY rear suspension to have a reasonably small toe angle?

My rear upright is a bit different than standard due to using the BMW E36 hub but I believe that the pricipal is the same as the Sierra set up.. So I will add shims between the hub and upright for toe adjustment. If I remember correctly Andy H at Suturn said the same.

hope this helps.

[Talonmotorsport]

I've just worked out that my idea with the bushes does'nt work as you can't turn them D'oh! How ever a pair of eccentric? washers retained on the upright would work.

[spud69]

Yes you're correct Greame, small aluminium shims are ideal for adjusting rear toe in.

[deezee]

I've seen a few track locosts with a adjustable length lower wishbone. I'll dig out a photo.

Edit: A photo showing an adjustable length rear wishbone, to adjust toe in.

[flyerncle]

If you slot the front bracket and use a bolt with eccentric washers as per Audi/VW suspension this would give toe in/out adjustment,you need to place a stop on the bracket for the washer to act against.