Interesting Super Charger, Maybe a possible application?
 

Was surfing my Subaru forums, when I came across this.

http://www.raptorsc.com.au/Superchargers.htm

There was a kit make for the 2.5 RS subaru which is the n/a version of the impreza.. Then I started thinking Type IV and so on... The thing that seems like it could work is that it uses a belt type pulley. and I Noticed the relatively small size..Pluming and Fuel would then be the next issue...
I assume you could change the compressor housing to match your requirements.
Just figured I'd share..
Alex

Looks similar to the Powerdyne units used on a lot of 'Stangs. Could have some interesting apps, but like an A/C unit, I'd worry about overheating the engine. Pulley driven = drag. Not sure how it would specifically affect a T1 or T4, but would warrant a look.

How about this. Buy it, try it, and when you've worked out all of the details give it to me! :D