say you have a turbo with appropriately sized compressor and turbine wheels. assuming matching compressor and turbine covers, if you made the compressor wheel smaller and turbine wheel larger, what effect would that have on power and spool?

What about if you made the compressor wheel larger and turbine wheel smaller?

I think about these things when i lie awake at night lol

Im thinking a the turbine controls how fast the turbo will spin and the amount of backpressure? but what effects will the compressor have?

 

the compressor wheel will affect how much backpressure is created and how much air the turbo pushes out.