I agree that the basic original design (air heading solely into the tail) is most probably the best and simplest to use and modify from.
This is why I bought a large SPAL pull fan for mounting under the IC. Fits perfectly. Plus, there is room for additional fans.
Still not thrilled about warm IC air into the engine, bu I'd hazard a guess to say this may not be a meaningfully bad condition.
In my opinon.....all this additional effort is really only realized as real gains through sustained on-boost / track use.
Which just so happens to be my area of concern.
I use an Andial turbo inlet/outlet intercooler gauge setup - currently it is plumbed to measure air filter inlet temps and post intercooler temps.
My intercooler outlet temperatures used to be about 130 maximum; now they top out at 150. That is getting pretty toasty.
Which is also why I have the BlownSix 965 style intercooler waiting in the wings for install.
(For track use), intercooler temperatures are listed by two local builders as job #1 for engine longevity and sustained on track performance. His MOTEC data form 12 930 EFI installs bears this out - very interesting data to see. Proprietary too....
so no data to post. Stephen Kaspar said it well: "Intercoolers do not add power, they prevent you from losing (as much)"
As indicated previously through actual data, there is such a small net pressure in either the postitive or negative direction at the tail area - especially closer to the rear window you go that....
I derived these as the possible realistically workable/functional choices:
1) Wide open tail inlet area, no shrouds / push fans under the intercooler
2) Shrouded tail area / pull fan under the intercooler / small open area for air filter (essentially what I currently have)
Making certain that the inlet for the fan - either through the IC or off to the side/condenser/etc - is large for the fan to draw through.