Awesome thread.
My Starion has a fake hood scoop from the factory. aka "83 hood"
..
and here's what the under side looks like:
I always wondered why it was there but had no function, the scoop didn't vent into the engine bay or nothing. Turbo II FC RX7's had a nice scoop that was functional, they cooled the top-mount intercooler, so I figured I would gut out the bottom of my hood and try to route that to the inlet of my turbocharger (my ricer idea, lol).
So I asked a super smart friend, he said the same thing, you mess up the natural vacuum the engine compartment needs... that the engineers at Mitsu all factored into the equation. Even small things like the angle that an intercooler is mounted, they think of- crazy huh?
Can't we just compare IAT,OT,WT,EGT readings on a car in these two scenarios: with/without hood? Maybe on an autoX day, gives us something productive to do, lol. I don't think the difference would be significant at all either way, as driving with no hood vs having a hood isn't. So maybe it just comes down to style? I ended up not doing it because the turbine gets hot enough to mess up the hood paint if I remove the heat shield under the hood.
Interesting, curious how serious this issue is on sub 300hp cars, lol. I can see the issue as far as maybe water temps going a bit higher than usual, but what if on a particular car it lowered IAT temperatures at the same time?