Re: Some Boost Controller Info

[Robert Houk - WorkGroup Server Firmware <Robert.Houk@East.Sun.COM>]

   >The smart controller can actually target the 2Bar absolute, and allow a
   >1.2Bar boost at 10,000 feet in order to accomplish the 2.0Bar goal.
   (Of course a drawback of this is that the "smart" controller can
   outsmart itself and overrev the turbo in the process...)

   A question about this turbo over-rev business: are you speaking about
   pushing the turbo over the surge limit by allowing an excessive pressure
   ratio?

Umm . . . I don't know how to answer that one . . . other than to say
that -- as in the hypothetical example above -- building 1.2Bar requires
a lot more RPM than 1Bar boost for two reasons: first just building a
higher boost requires more compression; and second you're starting from
a lower pressure to begin with, which requires even more compression.
I was thinking about the physical RPM limits of the turbo, both in terms
of the bearing, and the turbo wheels themselves fragmenting. I wasn't
thinking in terms of the fluid dynamics of the air being compressed...

					-RDH