Have an Idea..

[BJS]

mike I'm not missing the point with the turbo spinning at a fixed rpm it will provide pressure up to a specific air flow volume then when the engine demands/wants more air it will be a restriction to the air flow. This is why in a sequential turbo setup the small turbo is 1. usually wastegated & 2. can't be too small or it will hinder high end performance and leave the big turbo starving for air.

The most common failures on these are either the center bushings or intake wheel being chewed up, rarely do exhaust housing or wheels fail.

 

[my78r100s]

Actually, the point is it won't be spinning at a fixed rpm. It will vary according to vacuum and throttle position, hence the variable part of the equation. If nobody has a blown/bad unit, I'll sign off this thread and call it good. Cheers!!!