Bravo.

Consider closing the space/gap on the plate in front of the first vane. Then either lower the subsequent units (3/8" or so) or increase the height of the first, likewise. I cannot tell from your pictures but they all appear to be similar in height and there is an opening in front of the first vane (maybe not, though).

I doubt you will want to do this from an aesthetic position but also consider increasing the angle (>vertically) of the first unit or alternatively add a slight radius (up) to the top of it (swell). This would create the low pressure zone needed to exhaust the frunk with greater efficiency.

You can explain all of these oddities to those "at car shows or WCR" as an actual "functional" design; not just a design.

Another way around the issue, but also solves the issue with out adding a piece of angle in front of the vanes.

If it does not work you can always do it again, and again.

Pics don't do justice to the real thing. After seeing the "live" versions I'm liking the straight version even more in black. Chris is a talented craftsman and whatever version he decides on will be great. Thanks for letting me visit the workshop and see the ever evolving car!

Credit where credit is due: @RetroRacer @Rand @AzBanks @914forme @Cracker @bbrock Sorry if I've left you off the list. I'm working from my (failing) memory.

Presenting the TonyVents, RandAzBanks Black Edition ™ design, ready to be cut. This also incorporates some changes I decided to try after seeing everything painted black.

- extended the front of the panel so the vent starts right behind the headlight bucket. Seeing things painted caused that area to jump out at me. Tony (Cracker) also mentioned this one.
- lengthened the "bend channel" on the first vane so that once bent, it'll be a bit taller than the rest. It's about all I'm willing to do to create a dam to help create high pressure at the front of the vent. Is this ideal? Dunno, doubt it. But it should help while still meeting my goal of looking the way I want it look.

Back in a bit with pics of it installed. Fingers crossed!

I like the black but I think it would look even better if it matched the color of your wheels.
But then again, I am a sucker for dark grey metallic.

Holy Jebus, man! First it's the angles and now you're complaining about color?
No Christmas card for you...

OK, here we go. Let's tease this one, shall we?
Cut but not yet bent. So far, I think I'm liking that "no gap" at the back of the headlight cover.

Hey, all you critics - Be like my vents: Get BENT!

Looking good to me so far...

And I'm giving a go to @Cracker Tony's comment that I try varying the angle of attack from more to less across the vanes. This is only eyeballed at this point so no comments about lack of uniformity of change.

I must have miscommunicated, Chris - same angle but decreasing height (slightly) from front to rear. Here it is...

Click to view attachment

Chris, I'm coming over to your place tomorrow to VENT!

Apparently late to the game, and not understanding where the internal supports/stiffeners of the hood are, I would suggest only one thing and it is aesthetics in my opinion only.

Get the "inside" edge of the louvers to match up with the headlight cutout of the hood or eliminate the headlight cutout. I could draw it if you wish, but I think you could figure it out. Just my $0.02, but you didn't ask.

It was really damp when I rattle canned yesterday and the finish is a bit uneven - it doesn't look too good in these pics.

In any case, here are the TonyVents RandAzBanks Black Edition ™ in the metal.

Turns out that that minor rotation of the each vent really does change the look. I no longer see "floor heater vent"!

On the vane angle, after reviewing the yarn test and how it shows the major evacuation happening at the rear of the vent, I opted to open up those at the back, sorta giving up on the graduated angle idea.

There may be a couple very minor tweaks yet to come (I need to add a center strake to stabilize each vane) but this is the going-forward straight version design. For all intents and purposes, I'm calling these DONE!

Thanks again to you Gallery members for (most of ) your input! What a community...

As to next steps, I was honored by a visit from Andy @Krieger yesterday! He stopped by to do an in-person critique and gave me some great input for how I might address adding the screen/mesh. Let's see how this part goes.

On to the strake notch. Warning that this may get boring.

I'm no geometry expert but I have learned that when things bend at other than 90 degrees, especially in relationship to other things that aren't bending at 90, stuff ends up in places I didn't expect.

Each vane is bending at a different angle from all others and none are 90 to the frame. The goal is that once each vane is bent into position, these notches will align, the stabilizer strake will lock into them and run straight up the center of the vent, splitting the angle between the left and right sides of the frame.

Previous experience says this means I need to uniquely offset each strake's notch some magical amount and vary the angle of the each notch to take into account the angle of each vane. But how much? And what angle?

Here's my first go, with a temp center line, just to show how each offset moves out a bit more to account for that vane's increasing angle. There is actually some method to what I ended up with. I won't bore you with how I came up with it but we'll soon see if my thinking was even in the ball park.

And if anyone knows of some formula that I could use for all this, please let me know!

silver solder in place...

Well, I'm finding this thread vastly entertaining. Even though the vents should really be painted blue ... no, green ... no, red ... no, yellow ... no, plaid ... no, polka-dots ... errr, whatever you feel like.

Getting closer Chris,

Only thing I see is the first vent needs to be filled and just have the tip up on the front.

then you follow Tony's suggestion of decreasing hight of the tips. Angles are really getting good about mid way up your variable angle. I am away from my paper and pen otherwise I would draw it out.

Most of all have fun with the build.

Here's the basic idea I'm after. This is, as usual, the initial mock up to see what's what.
Also as usual, I have a ways to go.

I like that look the best.

I like the mesh idea. Can't wait to see what you come up with.

I'm ok with the missing Cristmas cars as long as I get my royalty checks when you become a multi-brazillionare from selling dark grey metallic RandAzBanks Black Edition ™ design hood vents. .0914% of net profits. Payable in 914 parts.

@914forme Stephen - Thanks. Based on what I know from the first yarn test, I'm leaving things pretty much as they are in this latest version. I'll do another yarn test to see how it works but I wouldn't be surprised if I need to increase the vane angle.

True but the other fender has backwards decreasing radius,, 914 is an uphill battle or favor..

Chris, @tygaboy that is looking very cool. I think once you get the center support finalized and add the screening of some sort, you have a done deal. I can't wait to come see it.

That strake looks soooo good!

Both sides in with temp rivets, ready for the next yarn test.

This is the first time both sides have been in and even though these aren't the final versions, I have to say, I'm thrilled with how the car looks.
I think they hint there's something going on but they don't scream it. Just what I was hoping for.

Fingers crossed they work as expected.

My current favorite pic.

Looking good Chris!! With both sides done, it really makes a huge difference.

Mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm

Well after 8 pages your almost there.... but you forgot KELTY360 and me




..."and lights! You could put lights underneath that would show when you open the vents.
"---KELTY360


" ...and sensors with thermal resistors hooked to the servos that would automatically open them when needed.

* and of coarse obviously turn on the lights... " ---altitude411



Click to view attachment

Chris,
I really like the look.

At the risk of initiating another 'do-over'
I just found this.
https://racelouvers.com/

It's more for those of us that don't have your skills but their testing is interesting.

Vent test V2. A few things:
- it's actually yarn! I hope you're OK with the color.
- the two pieces on the hood to the left of the vent show what's going on where there isn't a vent: No air lift. @Cairo94507 , you asked about this after that first vent video.
- there are a couple pieces of yarn in the vents that got stuck on the tape and couldn't stand up.

In all, same basic non-scientific result:
- hardly any flow at the rear vanes
- overall, the vents seem to work


https://www.youtube.com/watch?v=_E-bt9EEZeI


Then it was the fan test. Same deal as before, the belt still needs to be adjusted, sorry.
And you can see how those couple stuck pieces stand right up, once unstuck.


https://www.youtube.com/watch?v=Esx5A2JaaCo


I may do other tests but I'll probably move forward with these as is.
Next, I think I'll look into building a duct from the fans to the vents.

Then it's on to the rear of the car. What has Tony @Retroracer drawn up for me this time? Guess you'll have to keep following the build.

OK - I think you have a winner there. I liked the fan test the best. Looks like you have good air flow out the vents. Take a bow Chris- that is amazing.

Not done yet

See the picture, please close that space up, it will help you more than you think.

Click to view attachment

You can "lead a horse..."

Geez... What's that saying? "You can please some of the people..."

Excellent work! Looks like better flow than your first test. Wonder what the yarn looks like at 70 mph FANtastic!

Well....
I'm sorry, but I don't think you have done your homework.
You really should probably read AND UNDERSTAND this:

Comparison of aerodynamic properties of wool and polyester knitted textiles

And consider following this advice found in a thread Best material for aerodynamic tufting



I'm afraid it is back to the drawing board for you Now seriously, why isn't there a peanut emoji?

@bbrock - OK, Brent, you're on!

From the study:
"The aerodynamic drag force acting on a circular cylinder clad with knitted wool and polyester textiles has been investigated in wind tunnel experiments in this study."

Now I get it. Citing studies about drag on "cylindrical objects"? (Forget where I could go with that plus "wind tunnel"...)

In this case, the "you're a dick" comment essentially writes itself.

All I can say is that I if I run into any issues with lubrication, I certainly won't be mentioning it in this thread.

Since I'm nothing if not accommodating, and since Rand and AzBanks got to see their suggestions in metal, I figured it was only fair to take a swing at @Cracker Tony (not the vent designer Tony) and @914forme and Stephen's suggestions.
And thanks also, Dan @dan10101 ,for the link to Race Louvers. I read through the data and looked at their various designs. It was that additional info, on top of Tony and Stehpen's prodding that tipped things toward another iteration.

I'm calling these the "all business" version, vs the "form over function" RandAzBanks model.

Anyway, here's the initial go, unpainted so it's easier to see the details, and CAD of the 2nd version that fixes a couple of "oops, I shoulda seen that before making the part".

Key changes:
- a near vertical .75" wicker right at the front.
- all the vents run straight across, no more fancy, changing angles
- V2 CAD vanes: after bending, each subsequent vane is .05" shorter (from .6" down to .3")
- the 45 notch in the front corner is modified to allow the wicker to be as wide as possible while still not interfering with that hood rubber nubber thing.

It'll be interesting to see if there's any detectable difference when I yarn test this one.

Atta-boy...

I think that is my favorite of all of them. It's clean and simple in appearance.

I figured I may as well work out a possible next step: Adding the shop name!
My plasma table has an engraver attachment that can scribe the metal so why not? If I like it, I'll only add it on the driver side vent.

For the tool whores:
All that's needed is to establish the separate layers in CAD then set up the G-code to run the appropriate operation for each layer. I color-code each layer so it's easier for me to see:
- first run the engraver on the text (in blue)
- switch to the plasma torch to "drill" the holes (in red)
- cut the vent (in black)

Be sure to get the order right so you don't cut an outside shape then come back and try another operation on a "floating" part! Not that I've ever done that...

The 2nd pic is a snip visual of the overall cut program. This is what generates the code that runs the plasma table. Note that it shows I'm cutting 16ga stainless. That's just the "tool" I use to cut .063 aluminum. The "tools" are just presets for voltage, cut height, travel speed, etc. It has nothing to do with the actual material being cut.

Very cool feature! Adds a nice custom touch to your car.

Chris,

Your skill set is unreal. A true artist! No need to BS you, so many ideas from your build.

Thanks for sharing it with us.


Bob B

If you have ~ 1 minute to waste and you care to see how I spend part of my day, here's a quick video that shows how I preview the various operations ahead of cutting. Note this is sped up a bunch, just to shorten the video.

When I create the CAD drawings, I end up doing a ton of editing, copying, moving, rotating, snipping off end bits of line, etc. So before I cut the part, I use "single step" in this simulation mode (you can see the options on the right side) and preview each move and cut the torch will make to double check there are no straggler bits in the drawing that are asking to be cut.

Anyway, there you go.


https://www.youtube.com/watch?v=2LgCySbyspQ

This is getting way far away from anything 914 related so feel free to skip!
I haven't used the engraver for anything yet. And of course, it's adjustable for things like downward pressure, so I figured I'd better test it a bit first.

I'm not happy with the "punch" it leaves when it first drops onto the material so I'm still working on that. But it'll be pretty cool if I can get to look the way I want.

Max fail of the day: My engraver offset setting somehow got out of whack!

Man, I hate it when that happens... Oh well, a good reason to do a little maintenance on the table.

Note that this part looks messy because once I realized the engraving wasn't in the right place, I didn't bother cleaning it up.