New Hood Mod! NACA Ducts!

[SilverBullet75]

Hi!
I've been waiting a long time to get up the kahones to do this. I've always loved the way these look on High-End sports cars/rally cars/etc... So, I took 2 days off of work and just DID it! I installed NACA ducts in the hood... and yes, they are functional! (what do they do? well, um... they let air into the engine bay right now... AND LOOK COOL DOING IT!! ) Eventually I'll get them ducted toward the air cleaner, but for right now they just totally give the agressive look I've been wanting for my VX. I've attached some pics of the process and the end product. Let me know what ya'll think!
---JIM---

[Ldub]

Very Nice...I mean wayyy nice...
I've been wanting to do the same for some time...only I was thinking of putting one directly over the airbox to dump fresh air in,& the other in a corresponding loca. on the other side of the hood, maybe even another center forward loca.
I've liked the look of NACA ducts since the first time I saw them on a 69 GT 500.
Good to see what they'll look like, that really kicks!
An e-bay find ?

[Hotsauce]

Now make a collector for them and feed it to the airbox.

Gotta have some oomfh to back up the look.

John C.

[Ruflyf]

That is impressive, nice skills and appearance. I have thought of the same thing sort of, except I pictured them extruding upward rather than being inset. I think I like the inset better.

[Joe_Black]

Looks good! If they're to be functional, please post the amount of pressure you get at various speeds if you get a chance.

[biju]

So so clean. I love this mod, functional or not. It appears they align really well with the fangs, making them fit in really nice.

Thanks for posting!

-biju.

[SilverBullet75]

Thanks all!
Yes, eventually they will be plumbed into the airbox, but right now I'm out of budget $ and time.

As for the ebay question... no, these are 100% hand made. I started it by designing the shape on Adobe Illustrator. Then measured the insert for placement. Then, cut out the insert, cut the sheet metal hood below the insert, and used the cutout pieces as the "trays" for the ducts. From there, fiberglass and body filler went into play...
16 hours later...
They are done!
Only one thing I'm going to fix... I added a mesh screen. I don't like it though. It's used to cover up the bare sheet metal and hood structural supports. So, I'm going to cut the hood about 5 inches more toward the interior so that none of that will be seen, and I wont need a screen.

Oh... an for the request for pressures... Dude, I'm a jack-of-all-trades, but not a windtunnel expert! LOL I wish I could help with that info. It would be useful I'm sure.
Thanks!
---JIM---

[Ldub]

Just a thought re: mesh/ cutting more sheet metal/ hiding bare metal...

Flat Black Paint, Covers A Multitude of Sins.

[SilverBullet75]

LOL... believe me.. I've tried!

[Triathlete]

Hmmmm! Whats going to keep the water out on those rainy days?

[VCAMILO]

Awesome! The mod looks real nice... It never rains in AZ or in Nevada... LOL!

[Ldub]

Hmmmm! Whats going to keep the water out on those rainy days?

I was thinking a chunk of sponge or high density foam cut to fit (HAS to be black, of course), would slow it down to a drip on those rainy days & keep out most of the cold air during the frigid winters we experience way up nort.

[thedutchguy]

Me think you brave man to take two days of !

[iamjacksadrenalgland]

actually, NACA ducts are designed to vent air out from under the hood. there's a pressure difference between air flowing over the hood and air trapped under the hood.

this issue was debated at great length on a porsche forum that i used to belong to when 944 owners considered using hoods set up with NACA ducts plumbed to their intakes.

... and now for today's automotive fun facts ...

in 1979 porsche decided to build a turbocharged version of their normally aspirated 924. in order to accomodate the extra heat generated, they fashioned an NACA duct directly over the exhaust manifold/turbocharger.

in 1981 porsche offered a limited production 924 carrera GT which utilized an intercooler between the turbocharger outlet and the intake manifold. the resulting temperature drop allowed for more boost and more power. in order to provide airflow over the top mounted intercooler, they fashioned a large scoop on the hood.

[Hotsauce]

I was thinking a chunk of sponge or high density foam cut to fit (HAS to be black, of course), would slow it down to a drip on those rainy days & keep out most of the cold air during the frigid winters we experience way up nort.

Cold air= power. Cold fresh air is good, but obviously too much water is bad. My truck makes noticably more power on really cold days.

I really don't think you can get up enough air pressure for any signifigant ram air effect, but the cold air will help.

John C.