Hopefully this is still on topic for the OP to understand turbo capability. I can start another thread if not.
Looking at the system as a whole, the turbo is going to be linked from intake to exhaust, especially considering the fact that the turbine and the compressor spin at the same speed- i.e. connected by the same shaft.
On a turbo engine, once you hit the max flow capability of either side, performance will drop- same as hitting limits of other components. The compressor and the turbine have to work adequately, if not ideally, at the same speed, and also must work in conjunction with the engine flow capability for that speed.
Taking my engine for example, factory short block, comp 206 roller, decent ported factory heads, dut neck stock intercooler, stock exhaust elbow, 2 ½” down pipe, convertor stall 2200@zero, 4500 flash, 9% slip @ 5200 rpm, 255/60-15 ET Streets - is there a better turbo than a TE-44?
I personally would sacrifice some spool for better top end, but I don’t know if there is a good step from a TE-44, but under a 6262? I would like to keep the factory elbow.
Would 1.6 to 1.7 sixties be achievable with 118-120 trap speeds with just a turbo change for my combo(tuned correctly as an assumption)? I am willing to buy if so. Time in my sig was run with a 1.64 sixty, temp was right around 60F, running at LVD.