TheSamba.com :: View topic - Just thought this was an interesting visual

Mon Oct 08, 2007 1:55 pm

They must have painted out the massive eddy zone behind the box that continually sucks the thing backward.

Mon Oct 08, 2007 3:00 pm

Yeah, I thought the same thing. Interesting to look at anyway.

I would love to see a few T3 variations (stock Gl, Stock Carat, lowered Carat and a Westy) in a modern wind tunnel.

Anyone friends with a NASCAR team owner?

Mon Oct 08, 2007 3:15 pm

So, it says that the standard pop-top westy has the most drag, and the one with the least drag is.... the dehler profi. That makes sense to me. The one that doesn't figure is the lt28 (kinda like the lt28 anyway)

Mon Oct 08, 2007 3:37 pm

That camper's a dog. :lol: Look at that lack of air flow.

Mon Oct 08, 2007 4:20 pm

LT28? I see a camper on a vanagon singlecab. Similar to a Karmann Gypsy- man those things have got to be FAST :lol:
http://www.vwcampercrazy.co.uk/search_detail.asp?CamperID=1084&AdvertiserID=1611

Wed Oct 10, 2007 8:31 am

As to the sucking eddy... (sorry if anyone's named eddy)
I have a Country home camper, and they claim that a very slight spoiler on the back end really improves aerodynamics. Overall, it's a nice design for a poptop, and there's room in the front for a sunroof.

Wed Oct 10, 2007 9:00 am

Does anyone else think that filling in the luggage rack - covering it over smooth and level with the rest of the poptop - would improve the aero?

It seems like the perfect place to get a swirl as the air pushes over the top of the windshield...

Wed Oct 10, 2007 10:27 am

It might help a little bit, but that's like painting the barn when the frame is rotten. It'll make you feel better, but there's not much point in it.

If you want a box to be more aerodynamic, you would have to attach a cone to the back end. Large frontal area needs a lot of power to displace air, and can increase how much wind-buffeting you experience, but the majority of the actual drag is the result of having to pull a huge low-pressure zone around behind you. If Eddy was a Conehead, we'd all get 28mpg.

Wed Oct 10, 2007 11:50 am

Words of wisdom there. There's a guy on the subyvan group that made up a bustle for the rear end. Huge difference in mpg. Unfortunately, it's ugly as sin. If you really want to save on mpg, just drive a little slower. :wink: The gas consumption difference between 55 and 70 is ridiculous.

Wed Oct 10, 2007 12:24 pm

Quote: If you want a box to be more aerodynamic
I think that line says it all, it IS a box ! Kinda like taping wings on the side and assuming it will fly. Why go faster then 55, I want everyone to see how cool I am, if I go fast they might miss it. :wink:

Wed Oct 10, 2007 12:53 pm

When I am doing my next projects on my TD camper, I will be cutting out the rear of the engine bay around where the license plate door is all the way to the taillights on either side. The entire area will get the extruded steel mesh for a grate. The engine will be enclosed by the stock diesel diaper and perhaps sealed a little better. The intercooler will be on the left of the engine bay, the oil cooler on the right. Both will have skirting so that the air coming down the stock air scoop will need to pass through them. The extra area cut out from the back will theoretically allow that negative pressure into the engine bay and so assist airflow through both coolers and simultaneously reduce the "sucking eddy" a little. The VNT Mercedes 300TDT needs completing first:

http://vwdiesel.net/phpBB/viewtopic.php?t=10365

and then the TD Vanagon is at the TOP OF THE PROJECT LIST! :D

Andrew

Wed Oct 10, 2007 1:02 pm

Quote: If you really want to save on mpg, just drive a little slower. The gas consumption difference between 55 and 70 is ridiculous.

It sure is. We took a trip with my old 2.2 last spring. I usually cruise the highway at 75+ and get 19mpg. With the wife, camping gear, and 220 pounds of dog in the van, but tooling around the Four Corners area for a couple days at a leisurely 60-65mph, we saw as much as 23.5. Every tank was better than 21 on that trip.

Wed Oct 10, 2007 2:15 pm

Hey, it was just an idea. I never use the luggage rack anyway.

75?! :lol: The only time I see 75 is going down a long steep hill.

I generally try to stay between 55-60, even on the freeway.

Wed Oct 10, 2007 2:50 pm

I'm not running the same engine as you, although even the stock 2.1 was able to go 90+ on flat ground, and at 7000' altitude to boot. Just a 7-pass, though, I'm not hauling the extra weight of a Westy. But I'm still wrassling with pretty much the same aerodynamic limitations.