Bump steer

[alackofspeed]

Dear all,

One of my next tasks is to look into eradicating the bump steer on the front axle. It's very clearly there, but the effect has been reduced by fitting stiffer springs, and thus using less of the travel when pottering along.

Rather than reinvent the wheel, I'm hoping someone has already had a crack at resolving the bump-steer, and would like to share experiences. By which I mean, what did you adjust to get the best result.

My current plan is to start by measuring the toe change through as much of the suspension travel as I can (deck height of my jack will limit this, though I do plan to raise the wheels first). I'm then going to move the hub steering arm gradually through its arc, and see what improvent this yeilds (if anything!).

Any thoughts / experience, people can offer will be good to read.

Cheers,

John.

[limpabit]

Hi John.

Ian (merlinman) has been looking at this. Unfortunatley he's a bit shy on here! I'll give him a prod to see if I can get him to post. Or have a chat about his findings if any.

Not sure what, if anything, track developments done on the yellow race 5EXI.

[eaa53]

I have a quote from TD for you guys.


' Little by little the concept of changing suspension rather than accepting its foibles is taking root!

'John' on the 'Forum, has got it right. Fiddle and see what it does. The steering arm height on Ken's Yellow Track day car was adjustable and we fixed it.

We are writing a set up manual. (for a customer in Scotland) and we are thinking of retailing copies. The Bump Steer section is done but not the toe in page!

If the guy is struggling refer him to me and either by mobile or email. No 'promises' but I may be able to stop him going down a blind alley.'


If you PM me I will pass you his contact details, or Google them and you will find the contact details.

TD also explained to me the geometry relating to the lift off rear-steer issue and can explain why the historic set up behaved like it does, and they have a solution for the rear chassis strengthening.

Please be aware that although TD do not charge the earth for thier assistance they are a small commercial organisation and may need recompense for providing their knowledge and workshop time.



Hope this help.

eaa53

[alackofspeed]

Interesting, does this suggest TD monitor the forum?

[eaa53]

To my knowledge TD do not monitor the forum but I do talk to the workshop a lot about the issues. (i.e. most weeks recently)

TD modified all four corners of the Yellow one built by the mag to improve its track performance 2 years or so ago, it was also the first one I sat in.

There are other builders who are frequent visitors to the workshop so I guess that is another way they know what is happening.

I find them very easy to talk to and able to explain the theory behind the issues. Helps me justify the cost of the mods I am having done if I understand why they need to be done.

[craig]

Who's td?

[MikeR]

Track Developments - based near Castle Combe in deepest Wiltshire.

[alackofspeed]

Originally Posted by craig

Who's td?

They're the company that extensively modified Ken Morton's car, and Jon Combes' car.