Paul;  What is the rotrex system?  I have only seen bits and pieces of
the mail on this and have come in late.  Stu at Experimental Helo
magazine is curious as well.

BY

It is a high speed "gear" box to drive a centrifugal blower up
to 120,000 RPM. We are using it in reverse to extract power
from the turbo charger and feed it back into the e-shaft
for a turbo compounding effect.

http://www.rotrex.eu.com/