By extending the ends of the compressor wheel, BorgWarner has effectively increased the pressure ratio, efficiency and flow of the entire compressor.

This gives the S200, S300 & S400 pressure ratios and efficiencies that can normally only be had with larger, slower spooling turbos.
The extended fins do not hamper spool-up. The compressor wheel is designed to remove excess weight, reducing overall rotating mass. Of particular importance is the reduction of weight at the outer edges which is a major factor for reducing inertia. The weight reduction and where it is reduced allows these compressor wheels to spool FAST.

Another factor that increases the efficiency of the turbo as well as overall flow is the height of the compressor wheel blades. The BorgWarner extended tip version is over 20% taller than the standard 50 trim. The theory that the longer the air stays on the blades the more boost you can run and the more air it will flow thus improving the aerodynamics of the turbo. This extended tip compressor wheel is rated at more than 55 lbs/min vs. the standard 50 trim at only 49 lbs/min.

Turbocharger Name - S256
Compressor Wheel Inducer - 56mm
Compressor Wheel Exducer - 80mm
Compressor Wheel Trim - 49
Turbine Wheel Inducer - 74mm
Turbine Wheel Exducer - 64mm
Turbine Wheel Trim - 75
Horsepower Rating - 300-550