Lance, our Travato, has an extra solar panel mounted to his roof rack. This extra panel is right at the front edge of the roof. It always looked a little “unfinished” to me, and judging from the number of insect carcasses it collected, it was a pretty significant source of drag. Eventually, the Aerospace Engineer in me was bothered enough that I needed to do something about it. I tried ordering off-the-shelf fairings, wind screens, and deflectors, but none of them fit properly, or would mount properly to the Fiamma rack. I finally resolved the issue this past weekend by building a custom roof-rack-mounted fairing.
But before I could get started, I had to source some materials. If you want to follow along at home, here’s what I used to make the fairing:
- 12” x 60” sheet of black Acrylic. ¼ inch thick. (You’ll use slightly less than that)
- 4 M6 Stainless Steel Carriage Bolts and M6 Nyloc nuts.
- Aluminum bar stock. 1/8” thick. Approximately 48 inches.
- 12” x 60” plywood, MDF, or other pattern making maerial. ¼ inch thick.
- 8 ¼” stainless steel machine screws, fender washers, and nyloc nuts.
- Industrial Strength Velcro – Extreme (no, really, it’s called Extreme)
The first step was to work the plywood into a pattern. The pattern winds up approximately 54 inches wide, and I thought it looked better sloping inward toward the top. Here’s the first square-ish attempt.
I noticed a couple things right away. First, I couldn’t give this thing as gradual a slope as I had wanted without covering up the GPS/Sirius antenna on the roof. So this fairing wound up a bit more “upright” than I would have wanted. The second thing I noticed is that the ProMaster roof is not flat. There’s a gradual curve to the whole thing, and a couple cutout sections on either side. To make the fairing fit consistently close to the roof, I needed to scribe the pattern to fit.
After much scribing, trial, and error, I was able to get the pattern to within a quarter inch or less of the roof the whole way across. After that, I rounded off the corners, and called the pattern good.
With the pattern laying on the roof more or less where I wanted it, I used a bevel gauge to figure out the angles for brackets to hold the fairing. With those angles, I made one sample bracket out of some old galvanized steel bar stock I had laying around. That came out like this.
But that was just one bracket I bent up freehand with a hammer and anvil. I don’t have many metal working tools, and the prospect of making four identical brackets seemed daunting. It was so daunting, that I was able to convince Stef I needed a benchtop metal bender from Harbor Freight tools! Here it is:
And here are the 4 brackets I made up with it. Yes, they’re different lengths on purpose. The brackets in the center are not as tall as those on the outsides.
Still not quite done with the brackets though – I wanted the ends rounded and filed down to prevent damage to the roof. So first I ground the ends into a half-round shape, and then filed them down to remove any sharp edges.
Then I drilled a few holes in them and mounted them to the template to make sure everything lined up.
When I was satisfied with that, I took the template, and used it to template-rout the acrylic on my router table. I actually got some really great pictures of that, but they were on my phone. My phone – a Motorola Droid Mini – decided to FACTORY RESET ITSELF this past Sunday, destroying my pictures and all other data on the phone. Yes, I had backed it up on Friday, but that did me no good with Saturday’s pictures.
I’ll be destroying the Motorola Droid Mini in spectacular fashion in a future blog post.
Anyway – Acrylic works easily with standard woodworking tools. I used a ¾” diameter flush trim bit with the plywood pattern. This had the effect of producing a nice 3/8” radius on the inside corners. The other thing to note is do NOT try to drill acrylic with standard twist bits. It will crack. Use Forstner or spade bits, or a plunge router, to cut holes.
But like I said, sorry, no pictures of all that.
When I had the acrylic complete (it came out GREAT!), I turned back to the brackets. To keep them from scratching the roof, and to keep them from potentially lifting in the wind, I applied some Industrial Strength Velcro to the brackets and the roof. Apply the soft side to the underside of the brackets where they meet the roof, and apply the scratchy side to the roof. You’ll only need about 4 linear inches of the stuff. You can see it in this photo where I’m attaching the brackets to the roof rack.
You can also see that our front solar panel is attached to the roof rack as well. This actually made it more difficult to attach the fairing. I had to un-mount and re-mount the front of the solar panel so I could slide the fairing bolts into place. Most of you with Travatos won’t have to worry about that. And in order to access the track in the roof rack, you’ll have to remove three screws from the Fiamma rack (it’s obvious once you’re up there). Anyway, due to the tight clearance with the solar panels, I had to mount the brackets first, and then add the acrylic.
When I was done, it turned out not too shabby, if I do say so.
And here it is from another angle
It’s too early to say precisely what sort of impact this will have on gas mileage. In a completely non-scientific road test, it seemed to be about 1mpg greater than I’ve come to expect (at least, every time I looked down at the computer-reported mileage). I’ll have to wait to run through a couple full tanks of gas before I can give you a final verdict. But I’m pretty sure it won’t hurt the mileage.
But the bugs seemed better. On our road test, we took Lance out on the highway along the southern shore of the Great Salt Lake. Normally, this would coat the front of the vehicle in bug guts. But we noticed very few dead bugs on the fairing. Again, just anecdotal, but noteworthy.
And I’m very happy to report that I didn’t produce any kind of additional crazy wind noise. We listened closely, at every speed from “highway” to “parking lot”, and not one time did we get any howl, whine, rattle, bump, or buzz from the fairing. Visual inspection of the fairing after a day out revealed no damage.
So there you have it. Even if it has no effect whatsoever on mileage, I’m going to leave it on just because I like the way it looks. What do you think? Is this something you would want on your Travato? Let me know!