Originally Posted by blown 944

It still has to go through the volute. You don't machine that to fit the bigger wheel. No matter how you look at it you are still blowing through a small set of straws. The only way I would even try it is to use a large waste gate. The 10 cm may work but with the size of the wheel the spool would be slower than std size turbine wheels. The turbine housing can only flow so much air effectively. The 10cm would be maxxed well before the turbine wheel so I just don't see the point.

IMO a stg 5 size wheel would be about as big as I'd go in a replica.