where are these holes??
The holes are at the bottom of the airbox. It leads under
the car. See these diagrams:
See part 16 from this diagram:
It seems reasonable to think that it's there to create airflow by
generating a pressure differential. This would pull air from the
intake ducts from the front (part 20 in the diagram). You can see
that something like this might be necessary as the direction of
the intake ducts are perpendicular to the air flow. So perhaps
as air flows past the "rubber buffer" it might create a lower
pressure region causing air to flow through the ducting. It's also
conceivable that because it's constantly flowing air it may tend
to keep the air in the airbox cooler?
By adding scoops to the front you are forcing air into the ducts
so air is already flowing into this area. Keeping the buffer open
at least gives good, repeatable results as seen in all the RPi Ram
Air threads. It seems like plugging up the "buffer" you could be
building up pressure in the airbox. What is the result of this? Well,
just from my dynos it appears to add a bit of midrange hp/tq.
But this is just one set of dynos. Until others try this and do before
and after dynos I don't think we can conclude anything. Deknight
was supposed to run a few tests but I'm not sure if he had
the opportunity to dyno yet.
I don't have access to CFD software anymore (different lifetime
it seems) so I can only speculate on any of this. Maybe someone out
there does? Perhaps they could throw a quick model together and
run a simulation to determine theoretically if there is any benefit.
Of course that would be pretty hardcore.