> Anyone done it?

Dood, I don't know.  With the numerous turbo-charged air-cooled engines out
there, I'm sure it can be done quite "easily".  Redo your head gaskets in
advance, ceramic-coat the heads, valves and pistons, lower the CR, put
aircraft-quality head studs in, heat-wrap the exhaust, put in a stand-alone
engine management system, high-flow injectors, a tunable fuel-pressure
regulator and voila! Keep in mind you'd have to fabricate a suitable intake
system as the stock manifold would probably not hold the pressure, find a
place for an intercooler, and shield the turbo from splashing water in the
event of rain.

I'd love to see someone do it!

Chris S.
'85 Westy
www.knology.net/~vw/
http://groups.yahoo.com/group/wolfsburg_campers