No subject

all you could ever want in a turbo - Variable Area Turbine Nozzle (VATN) is
exactly what a turbo should be...ever seen the comparison of an Aerocharger
to a normal turbo on the same motor?  It's ridiculous how quickly they make
boost - like having a K24 for low rpms and a k27 for the top...
It is also unfortunate that they do not have an Audi application (yet?)  ;)

Later!  Richard 1990 CQ 202K
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I believe Audi/VW have an ongoing, extensive Variable vane turbo research
program, and in fact may fairly recently finally be using VATN turbos in
some small diesel engine applications in Europe.  IIR, I think I saw
something like that in the SAE bimonthly publication on new trends in
automotive engines etc.

BUT, my impression has been that in the gas engine world, especially larger
displacement gas engines, the turbos have not been able to satisfy most
manufacturer's cost vs. durability issues.

Hughes MacInness (admittedly probably dated) comment and summary of the
technology, has been "....Unfortunately, it's expensive and the hot gases
make it unreliable for turbochargers.  The mechanism must be made from
materials with high strength and corrosion resistance at high temperatures.
Even then, combustion products may jam the vanes." page 81, Turbochargers by
HP Books.

New technology &/or materials may finally be solving some of these problems,
but I think broad acceptance is still a ways off.

mlp