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Old 07-07-2005, 07:05 PM
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AdrianM
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Originally Posted by King-G
Interesting Adrian..

I haven't read Hodge's thread, but it has always been my understanding (from reading a number of engineering manuals) that Bump Toe out should be avoided.

Reduced steering angle of the laden wheel being the main reason, and also unpredictable bump handling response.

I have always used Neutral Bump steer, (on the Mi2 I use 2 x 2mm alloy spacers under the ballstud - With a long Tir Ballstud to ensure theres plenty of thread in the bellcrank to prevent it being stripped out)

pic: http://img8.exs.cx/img8/6192/F_gearbox.jpg
I thought just as you did. The laden wheel will straighten out as the chassis rolled with bump toe out and this is not what you want. However, the inside wheel will turn in more. As Todd explains it bump toe out gives a reactive Ackerman effect that increases turn in and steering in thigh corners.

This is one of those things that we can explain to death one way or another but we would be better off testing on the track. It is easy enough to try. Just remove one 2mm spacer from the bell crank ball stud, re-adjust your front toe and you will have bump toe out.

For neutral toe I mill the arm on the steering knuckle down to the mold parting line (~2mm) and add a 2mm spacer to the bell crank.
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