I was checking out CVT's and ran across this.

http://auto.howstuffworks.com/cvt3.htm

Toroidal CVT..

It looks kind of like the traction drives that have been discussed
here for Turbo Compounding..  I wonder what the RPM limitations for
the CVT style drives might be..  Could the input be run at
turbocharger speeds?


Regards,

Matt-

That is the key to make turbo compound work over a wide
range of RPM and horse powers.

Paul Lamar