Welded Diff'

["Stroes, Gustave" <Gustave.Stroes@xxxxxxx>]

>How does a car corner without a differential? Basic physics dictates that
in a
>given corner the outside wheel rotates faster on travels more than the
inside
>wheel hence the need for a differential. As one digester posted recently he
had
>a lot of skidding and chattering from his tires as he tried to negotiate
turns
>in his car with a seized differential.  How is it Porsche is able to run a
car
>with a locked diff?
>
>kenny_lam@domain.elided


Kenny,

The reason a high powered race car can get away with using a solid diff
(spool) is that under track conditions all four wheels are more or less
sliding the whole time anyway.  Thus the fact that the inside rear wheel
must slide a little more so that the outside rear wheel can make it around a
turn is not too much of a problem.  But it still leads to corner entry
understeer.  Once past the apex the driver can achieve any cornering
attitude he desires by modulating his right foot a.k.a. "steering with the
throttle."

It seems that the best procedure is to use the least amount of lockup that
you can get away with.  As is so often the case, more is not necessarily
better.

Gustave Stroes
Redondo Bch, CA
88 M3

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