turbo: blow thru vs. draw thru

On a draw thru, the closed throttle blades are also choking the compressor, slowing the turbo speed, too.

That fast thought? Thats alot of kinetic energy spinning at up to 130,000 RPM...and you still have the idle transfer slot. I would think that would create a huge vacuum draw on the carb, but I guess decelerating a V8 from 7000 RPM is about as taxing on the throttle blades and idle circuit. OK, back on track....