Problem here is, alot of you guys keep talking about different turbo's. You have everyone confused as to which is which.
6131 = TE60 + GT61 compressor wheel
6152 = PT52 (or TE52 or PTE52) + GT61 compressor wheel
PTE54 = TE61 = old style 60-1 compressor wheel and T04B 69 trim exhaust wheel
IMHO, the 6131 will not be going 10's any time soon, unless you have a really well built motor and very high flowing heads.
The GT61 compressor wheel is considered a lower pressure wheel, but makes more power than the old 60-1 compressor it replaces at lower boost levels. Each motor will be slightly different but it has been discussed multiple times in the past that the GT61 compressor wheel will be done in the 24 -26psi range on most Buick motors. Crank the boost higher than that and you won't make any more power.
If you intend on running on the street then a turbo with the GT61 may be a better choice as you will make more power and spool quicker at the lower boost levels.
If you have a car that you want to keep pushing, and run at the track often, then something you can keep turning the boost up on and will keep making more power is a PTE54/TE61. This is a proven turbo and guys have run it into the 30+ psi range and still made more power. Try that with a GT61 compressor and it will be dead @ 24 - 26 psi.
No hype, no BS, just the way it is....
Hope that clears things up for a few guys.