CudjoeScott

I pulled my air filter out to clean the engine compartment the other day, and I was confused by the NACA duct.

I have always wondered why the nose grill had some of the "vents" blocked off ...



So I pulled the air filter and tried to find where the air flowed from the NACA duct to the air filter ...



Am I totally without a clue (which is very likely), or am I to understand that all air from the NACA duct flows from these few holes in the shroud?

So does the air come from another source or are these the only vents into the air filter?

MIKE LAZENBY

Shine a flashlight from the outside,then you will see. Mike

C5 Frank

Like most air scoops on new cars, it is more about the look then the function!

Silver05GTO

There has to be some blockage of water, if not water would pour straight into the intake from the NACA duct. But it is functional as does allow airflow.

Keiffer

It's there strickly for looks, so says my dealer

spdmn75

I gutted mine out and will and will post pics in the next couple days

BearZ06

Try searching NACA Duct, some good info there.

DSteck

Your dealer is stupid.

If you have an aftermarket intake, it's really easy to see the filter element from outside the car. You have to look down at an angle, but it allows a decent amount of air in.

2kvert

It is not a straight pass-thru design. Having had my front bumper off, I've looked at the piece in question. ALL Vettes have this same piece behind the bumper cover. Just the Z06 and ZR1 have the opening in the bumper cover to expose it. Actually, the few holes that are there don't allow much air in as directly behind those openings is another piece of plastic. There is some airflow straight in but it is immediately forced downward so it does not directly enter the engine compartment. Like some have said, it can be modified to flow directly in but I'm not sure how much gain you would receive versus the water injestion risk.

AFVETTE

I recall Jim Hall outlining in very clear detail that the Z06 NACA duct IS FUNCTIONAL and DOES provide cooler air to the intake.

I'm sure someone will find his highly detailed thread and re-post it.

Tom

CudjoeScott

I don't doubt that cool air does get in there, I was just shocked that (it appears) only four small holes allow the air to pass through. I guess that's one of the reasons that a lot of vendors require cutting the shroud to get their aftermarket CAI's to function properly.

04_Z06_CE

yes look at jim halls prior posts he did a thoughrough research on it ...the naca does work

Halltech

If you want to check it out for yourself, wait until your car is in a dark garage, take out the intake, put a trouble light in the same location, then close the hood (leave it ajar to prevent cutting the cord).

You will see light coming out of this area. Here is what we do to clean up this area:

Remove the plastic bezel in the front. It comes out with little resistance and has a piece of double sided tape on the bottom.

I used a snip to cut the plastic in the front, then dremeled the inside area(very carefully) to open this up. You should use something to protect the paint in the duct area to prevent scoring this area.

When finished, reinstall the plastic duct bezel.

If you are not inclined to do this, DON'T.

It works as is from mother nature.

Jim

mirage2991

just because it's not "obvious" doesn't mean it doesn't work.
I've HPT logged it and it works, with steady driving, IAT indicated where about 6 degrees hotter than outside indicated air temp. Now, it does lack some efficiency at lower speed or dead stop, but for all purposes and specifically for road racing purposes, it works!

Halltech

You are dead on. The opening can be enlarged, but with risk of damage to your fascia if not careful. We see a 2 degree variance with our Beehive onboard, and a gain of only 9 degrees sitting for 1 minute.

The IAT (intake air temp) soars 50 degrees in 60 seconds of idle and standing, without the Beehive. Bottom breathers get their air from the radiator area, which does nothing to help during a 1 minute stop. Our Beehive couples the NACA duct with two more ducts on either side of the Killer Bee filter.

http://www.halltechsystems.com/category_s/87.htm

Halltech

Before

After modification. You can see the Killer Bee easily. With the Beehive onboard, Ram Air goes directly into the filter and is contained within the Beehive. This was water tested for 890 miles without any issues, in a moderate downpour. If you have butterflys from this type of mod, don't do it. Leave it stock. I wonder why so many other systems breath from the radiator area, when mother nature always takes care of her bees.

Halltech

Carbon tax on this Super Beehive is substantial, but you get the Beehive and the radiator bezel in one piece.

This whole piece weighs in at an incredible 19.4 oz.!

Z5108

Bump