Blow off or Bleeder Valve

[scarface_x360]

Hey guys, I have an 87 GN, freshly rebuilt engine,, quite a few mods. Running 16-17 pounds on the street with stock turbo. Every time ive been at the track ive seen other gns, not running blow off valves.; I do not have one either. My question is, why don't these guys run bleeder valves? I heard it is better for the turbo to run a bleeder valve? Is that true? Also, Will it hurt the performance of the car to run a bleeder valve?

Thanks guys