sure its been done before but causes it & how to stop it, its a book locost
I feel like pet detective ! If you have seen the film.
Cheers
Steve

Have a look at this thread

http://locostbuilders.co.uk/viewthread.php?tid=39053

Cheers

Mark

Bumpsteer is where the tracking changes as the wheels move up and down.

Or if you move the wheel through its range of suspension it will steer.

It is caused by the track rod and suspension wishbones working on different arcs.

To cure it you first get the rack the correct length and at the correct hieght, then tweak it by altering the hieght of the track rod ends.

It is too complex to explain just how you design a system with no bump steer, but it is commonly described in suspension books.

John

Testing for bump steer involves eating loads of pies.....


and you end up with sore knees.


Paul G
Rescued attachment Bump-steer-test-s.jpg

Not sure i like your new bodywork paul!

Thats the funniest photo I've seen for a while.

If you had posted that without the bumpsteer explanaition people would have thought you had finally lost the plot!

It's a caption competition!

David

That is one of the easiest ways to check for bump steer, especially if you attach 2 pieces of wood or box section to the wheels pointing forwards to amplify any bump steer.

John

The new nosecone was an @rse to fit.

Joel asked about this a while back. I've never felt the effect you are talking about with my car. When I built it I had my own theory that the track rods should be parallel to the bottom wishbones to help combat the bump and so I mounted it lower than the book measurement and my brackets also set it a bit further forward.
Rescued attachment rackpos.jpg