Hiya All. I have purchased a high flow compressor setup (machined backing plate, lager compressor wheel and machined cover - I think it's off a T3/T04 hybrid setup) and I'd like to know if the .48 exhaust housing combined with the high flow compressor will allow faster spooling (due to .48) and solve the top end power issue by having the high flow compressor? How will this configuration compare to my current setup which is a standard compressor with a .63 AR exhaust housing? Thanks in advance.

It will spool up quicker, it might even cause the oversized compressor to surge pretty violently, depending on what trim the compressor is. The smaller exhaust housing is going to cause massive back pressure buildup., and that will limit top end power considerably. Provided it does not actually surge, it will be very responsive down low, but have a much reduced top end power. If you are after power, you really need a bigger turbine housing, not a smaller one. That exhaust housing might suit a two litre engine better.