This is a BM3 thread. Need a new thread for turbo physics. I'll provide the following, hoping to close the debate.
All you guys need to know:
1) PS2 works well with EWG OTS.
2) PS2 PWG is a PITA to tune. PWG OTS 2H is a hit and miss. In most cases, you need custom and hugh amount of time to dial in PWG PS2 on a flash only basis, if ever possible at all. Many tuners just gave in to piggyback stack up.
3) PS2 has noticeable lag compared to stock turbo. No question asked. No ego stuff. No whitewash. It's a matter of if the power is worth the lag, which it is in my opinion.
I've built, driven, tested and logged PS2. There is no denying lag be felt on the road and be seen from log. I've also experienced almost all the hybrid turbos that's ever available to N55s all the way from PS1, PS2, Dinan, VTTO STG2, TTE460 and G Power 500 (my current setup).
On pump gas, PS2 seems to flow more than octane can support, in other words, you can happily leave headroom, making less heat for power consistency.
See below thread that physically compares PS2 to other turbos. PS2 is as big as a hybrid can get. Take a look if you want.
https://f87.bimmerpost.com/forums/sh....php?t=1501569