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Jack up toe in
hemibum - 13/5/09 at 09:38 PM

Don't laugh. But, we know that we don't have enough castor on our setup as self centering is zero. Camber is good @ about 1.5 degrees, and toe in is around 1 degree. The car is very driveable , apart from, the lack of self centering, which actually is quite go kartish.

The unsettling part is that when we jack the front up to get the front wheels off the ground, the wheels toe in to quite a remarkable degree.

Should we just shoot ourselves , or is this fixable?

I should explain that this is on a Locust which originally had "Tina" Mk 1V front suspenders which we cut off and replaced with wishbones and coilovers from Rally Design. Rescued attachment DSC01091.JPG
Rescued attachment DSC01091.JPG

MikeRJ - 13/5/09 at 09:51 PM

quote:
Originally posted by hemibum
The unsettling part is that when we jack the front up to get the front wheels off the ground, the wheels toe in to quite a remarkable degree.


Sounds like fairly chronic bumpsteer, I guess you didn't fully copy the Cortina suspension geometry?

You will need to experiment with the position of the steering rack, i.e. move it up and down and forwards and back to try to dial this out or it won't be very pleasant to drive.

Regarding the self centring, what castor have you designed in?

Looks like you might want to turn the gas up a bit on your welder as well!

[Edited on 13/5/09 by MikeRJ]

mark chandler - 13/5/09 at 09:52 PM

You need to move the steering rack around to minimise this, its 'bump steer' do a search on this phase.

A classic book chassis will always suffer unless you shorten the rack.

nitram38 - 13/5/09 at 09:52 PM

The changing toe in is caused by bump steer, because your steering rack track rod ends do not follow the same arc as your wishbones.
Do a search on how to sort this.

britishtrident - 14/5/09 at 07:21 AM

steering rack is mounted too high