Whats the most you guys are spinning these turbos too? The effiency in mine started dropping off past 23psi where it made 508, at 25 it made 527 so we stopped there.

Sound about right? This was on an 84mm GSR motor, stock port head.

 

On a VR6 with a t04 .58 hotside they start to run out of steam at about the same levels (500whp and low 20's boost). You can push em a little more but they really get out of their efficiency. Not a gsr I know but should give you an idea.

 

that was with a .58 hotside, i think you could push a little more since the t3/60-1 is a tad larger but pretty much reaching peak output and overspinning it out of its efficency range is pretty much worthless.

 

the t3 60-1 i think i rated to around 580