What is "clip" in clipped wheels?

[Taffy]

I hear that wheels are clipped. What exactly is this. And what effect does it have on the turbo? I searched and got nothing. Thanks.

 

[turbo buicks]

from the Garrett PDF catalog on www.limitengineering.com

Clipped Turbine Wheels- When an angle is machined on the
turbine wheel exducer (outlet side), the wheel is said to be
‘clipped’. Clipping causes a minor increase in the wheel’s flow
capability, however, it dramatically lowers the turbo efficiency.
This reduction causes the turbo to come up on boost at a later
engine speed (increased turbo lag). High performance applications
should never use a clipped turbine wheel. All Garrett
GT turbos use modern unclipped turbine wheels.

doesnt sound like a good thing to me.

 

[Taffy]

Interesting. Most of the Talon/Eclipse vendors sell clipped wheel turbos. Mostly 16/18/20G Mitsubishi turbos. I figured that a properly designed wheel would be the best route.

Thanks.