Prototyping Vanagon Aero Wing

[Pingora]

[Pingora]

Also, that image with the streamlines around the vans is cool, but doesn't show anything that happens after the stream leaves the back/top of the van, which is the most important part.
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1990 Vanagon Carat
2002 Suby 2.5 Mizu Bokusa
17" wheels, 26.5" diameter tires

[Merian]

The streamlines show that a wing would have to stick up higher to intercept them.

They also show no turbulent eddies so maybe they are not very realistic.

Preventing relative lift at the front may prove critical to vehicle stability if a rear device is fitted.

If you have a background in auto aerodynamics then you must surely know about the 911 and the need for a front dam when using any wing or even a ducktail on the back. It is not about drag.
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[Abscate]

[Pingora]

Merian,

There you are correct. The 911 wing is not about drag, it's about downforce. That is a totally different type of wing/spoiler. This type is designed to reduce the wake behind the car, and the drag, much like the system designed for the big rigs that was pictured above. It's purpose is totally different. The idea is to simulate adding a big long tapered back end to the car without actually doing that.

The good thing is I'm actually doing it, so I will have some real world test results. It could be hard to quantify MPG gains, but at least I can report solidly on wind handling if nothing else.
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1990 Vanagon Carat
2002 Suby 2.5 Mizu Bokusa
17" wheels, 26.5" diameter tires

[ThankYouJerry]

Take for example the 1964-1972 Alfa Romeo Giulia Super sedan. By looks alone, at best it was a phone booth with wheels. In reality, thanks to it's Kamm tail design, it was more aerodynamic than Porsche 911s of the same vintage!
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1990 Multivan - "Ohana"
1.8T, Auto w/3.27 R&P + Peloquin TBD

[thatbaldwinlife]

But would you want to run this on your van for 1-2 mgp increase? Seems like a lot of hassle and goofy looks for a small gain. My van is too pretty for that
nate
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1987 Westy
Insta: @Thatbaldwinlife
Vanagon Adventure and DIY videos:
That Baldwin Life YouTube Channel

[Ahwahnee]

X2 - If mileage was all that important to me I would just slow down a tiny bit and get the same gain. Really, I think many could improve their mileage by that amount and more with some careful maintenance.

Still, it is an interesting exercise to watch.

[Pingora]

Sure, I'd easily run it for 2 mpg increase. But I also am more interested in side wind handling almost. There was a thread a while back where someone added a long tapered tail (different than the short one posted above) and he said the most important effect it had was to significantly reduce side wind buffetting. My guess is that the reduction in sharp pressure gradients around the car made it less sensitive to small changes in angle of attack relative to the wind.

Also I think it will look cool when it's done in a funky way, and the idea is it's easy to take off. If it worked I'd only use it on longer highway trips.
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1990 Vanagon Carat
2002 Suby 2.5 Mizu Bokusa
17" wheels, 26.5" diameter tires

[bobbyblack]

On mileage, I agree. Recent trip across 2 states with 80 MPH freeway, and I did push my 2.1 WBX that fast, or slightly faster (top end of the Tac's green dotted zone -- like 4400rpm?) and the MPGs were about 15. I CAN get 20 MPG if I stay in the take-it-easy speedzone (like 55-60).

On looks, I also agree. I would think it strange to put a similar thing on my rig.

On science, Way to go! Love it, and keep at it, and THANK YOU!!!

I look forward to seeing it finished and tested, keep up the great project!

I WOULD put one of those on my rig for a trip across those states again, no question about it. Funny looking or not. I'd like a way to install it and remove it easily tho, for around town vs the annual family trips.

In a real world scenario, please consider what adding a bike rack/bikes to this would mean. I'd like to find a way to account turbulence of those as well. Maybe a clamshell type cover for the bikes that would work with the wing?

-bobby
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'87 Westy 'Flossie','86 Westy 'R1','86 tintop GL - Subi2.2 'J2','83.5 stock tintop L 'ZoomBus','74 Karmann Ghia, '63 Notch

[thatbaldwinlife]

With load rated 16" tires and the T3 bushing kit, my Westy is fine in crosswinds. The biggest factor is my Yakima box on top but that needs to stay. We only drive 65 mph tops on any highway we are on even with our firebreathing RJE 2.2L

Have fun with the project.
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1987 Westy
Insta: @Thatbaldwinlife
Vanagon Adventure and DIY videos:
That Baldwin Life YouTube Channel

[MarkWard]

[Wayne S. Johnson]

This is what aerodynamics looks like.

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[Merian]

yes, or look at a Prius - carefully


The 911 "wing" also was about drag not just downforce

- it appears further study is needed here



to improve mileage a better, more modern engine would help, and a hybrid setup would help a lot
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[Pingora]

Bobbyblack, thanks for the encouragement, and the reasonable non-reactionary response.

For the most part it seems this should be called the VW Naysayers forum.

Merian, at least stay consistent. In an earlier post about a 911 (which by the way is not at all the topic of the thread) you said "it is not about drag". In addition, if you just looked at my signature you'd see I have a 2.5 Subaru engine in my van, and it's a 1990 Carat which has the front air dam.

Yes, there are other ways to gain efficiency. This thread was not meant to be about any of those. This was a design developed by PHD students for a purpose, using advanced fluid dynamics simulations. The design makes intuitive sense to me as well, so no harm in trying it out.

Also have you noticed that almost every boxy modern minivan or SUV has some sort of rear spoiler/wing/whateveryouwantacallit?
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1990 Vanagon Carat
2002 Suby 2.5 Mizu Bokusa
17" wheels, 26.5" diameter tires

[Jake de Villiers]

[bobbyblack]

I got a chuckle out of the Naysayers bit. FUNNY!! I like a good laugh once a day or so

As for the mention of other square boxes having something like this, yes!!! I keep noticing how my cars with square backs (SUV's, wagons, Vanagons, etc) get grime and dust on the back. In the market, my cars are usually lower cost units, vs. the possible 'upgrade' versions which have that rear wing/foil whatnot. The other folks who got the costlier version of my square ended thing that have that wing are not nearly as dusty.
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'87 Westy 'Flossie','86 Westy 'R1','86 tintop GL - Subi2.2 'J2','83.5 stock tintop L 'ZoomBus','74 Karmann Ghia, '63 Notch

[MarkWard]

If the Wright brothers had listened to the Naysayers we'd still be tied to the ground. Trial and error is probably a more valid way of testing, vs sitting at a desk crunching numbers. The problem with a lot of folks is their unwillingness to fail at something. Failure is how we learn. If we are afraid to fail, then we gain little.

Back in the early 90s, the VW dealer guys said my TDI conversion would never work. Now they are popular. Good thing I did not listen to the naysayers.
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[Pingora]

I got one side of the Dacron ironed on. Next time I will add more ribs, or sheet the concave sections at least, but it will work for a first prototype at least. The Dacron is attached with Heat'n'Bond iron on adhesive. I'll add a layer of epoxy or maybe some UV cure surfboard resin next to waterproof and make it stronger.

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1990 Vanagon Carat
2002 Suby 2.5 Mizu Bokusa
17" wheels, 26.5" diameter tires

[Abscate]

The naysayers on mods like this are usually (>95%) correct...stuff like this...