true, obviously not running a DV and letting the air pass back through the compressor would put torsion on the shaft but like you say as to how much is a bit of a guess.

its just something i see that pops up in discussions from standard boost levels upwards people say its bad for the turbo, as above the torsion seems to be what people are getting at but if people are running 30 psi like this a doubt 10psi is straining it much.

i guess with out lots of testing its a guess, i wouldnt have though snapped shafts would be that common would you think it could snap blades off?