[BiturboS4] After run pump question

[CWurts12 at mindspring.com]

I have been looking into this question as well.  One of the aspects of the
my old 5ktq and UrS6 that I liked was the after run pump and fan.  If I
understand correctly, the Biturbo S4 has the feature, but it is not
activated until 240 C degrees, I level which is rarely seen.  A well
respected member of this group informed me that this is adequate given the
advances in turbo construction.  He said that he is unaware of any turbo
failure in the biturbo car due to coking.  Spin down is the issue, and only
when the temps are high enough to alter the shape of the turbine.  This is
all I have learned so far.  I would be interested to learn more on this
subject as well.