I hybrided my t518 into a t620 .300rpm more lag pulled like a train till redline with a full 3" exhaust turbo works less =less HEAT means more psi max 30hp more then stock at 16psi .

Are you saying it was 30hp more at the same psi with the modified T518z (18G) with T6 (20G) internals? Or did you have to up the psi to gain that?

When does the GT3071R and GT3076R spool/reach full boost by? Would they both carry power all the way to redline in an AP1? How would these turbos stack up to the T620?

Bump this guy back up to the top. Interesting discussion, and I'm thinking I might just replace my stock Greddy turbo instead of trying to rebuild it. I can see a rebuild in the future, and I want to do all my research now.

Had to run more psi to get that power 360whp the turbo just works less to get given psi ie less heat = a higher psi can be got :thumbup:
But the same turbo on a elm would give 400whp with less heat ditch the log dude .

The 71R should spool almost as fast as the 518z. 76R close behind that. Both can carry full boost to redline as long as you are at reasonable boost levels on a good manifold.

I think I am going to have my 518z upgraded with a new compressor wheel (20g) and then get a ramhorn manifold made...should make good power.