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-   -   Which way would you install skibox (https://ecomodder.com/forum/showthread.php/way-would-you-install-skibox-15811.html)

Vekke 01-16-2011 06:33 AM

Which way would you install skibox
 
Skibox Skibox - Zorg bij de ski voorbereiding voor een goede dakdrager

I was wondering why skibox factories instruck to install them this way and not the other way to get kammback effect?

dennyt 01-16-2011 11:46 AM

Do an ABA test.

Piwoslaw 01-16-2011 03:14 PM

Quote:

Originally Posted by Vekke (Post 215384)
Which way would you install skibox

Inside the car. That's where the Wife and I carry our 2 meter long crosscountry skis.

http://skiinformatie.nl/wp-content/u...-dakdrager.jpg

I think that the proposed way of mounting would be better aerodynamically. Yes, the front could be a little more blunt, but the rear has a sharp cut-off, so installing it backwards would not be advised.

Vekke 01-17-2011 01:55 AM

I did some searching and found these videos:
about bars:
http://www.youtube.com/watch?v=v6BUO1RLt_g

I want my own miniature wind tunnel, like that :D
and at the box:
http://www.youtube.com/watch?v=1exOXa-5WYo
Version at the 1.30 has already a kammback shape ;).

Piwoslaw 01-17-2011 02:39 AM

1 Attachment(s)
One thing I noticed on the vids is that the Thule boxes were always mounted in the center of the roof, while most drivers mount them asymetrically on one side (because it's easier to reach). I wonder how much of an effect that has?

I'd like to see nice side pictures of windtunnel testing...

I did find this aerial view, from which you can clearly see the car is Kamm'ed much better than the box:

http://ecomodder.com/forum/attachmen...1&d=1295249685

I bet that one would give Aerohead a headache;)

euromodder 01-17-2011 08:23 AM

Quote:

Originally Posted by Piwoslaw (Post 215541)
One thing I noticed on the vids is that the Thule boxes were always mounted in the center of the roof, while most drivers mount them asymetrically on one side (because it's easier to reach). I wonder how much of an effect that has?

As there's more drag on one side, there will be a slight yaw moment which will need to be corrected through the steering - and steering increases tyre resistance. I doubt it'll show up during driving and be much worse than a centermounted box though.

Probably the worst thing anyone could do, is putting 2 narrow boxes on the roof.
There's quite a few instances in aviation history where putting 2 external fuel tanks next to one another didn't increase, but decreased the range of the aircraft.

Piwoslaw 01-17-2011 10:19 AM

Quote:

Originally Posted by euromodder (Post 215561)
Probably the worst thing anyone could do, is putting 2 narrow boxes on the roof.
There's quite a few instances in aviation history where putting 2 external fuel tanks next to one another didn't increase, but decreased the range of the aircraft.

There's something I didn't know... Kinda make sense, though, thinking about how much the gas pedal gets pressed when being passed by someone else (someone BIG, for example). Maybe I should get a sticker:
DO NOT PASS!!
(IT KILLS MY FE)

aerohead 01-21-2011 06:26 PM

which way: stability
 
My opinion is, that with rounding of the trailing edges,and reversing the carrier,the drag would be reduced.
The issue might be how that would affect the center-of pressure for the car/carrier combination.The 'streamlined' form would push the COP forward,which is NEVER good for crosswind stability.
So maybe for safety,THULE compromises a bit on drag.Not bad thinking!

dennyt 01-21-2011 06:31 PM

I think putting the box backward would raise the stagnation point and force more air under the box, which would increase the interference drag.

dennyt 01-21-2011 07:46 PM

Ski boxes should be fully faired-in. Like this!
http://i11.photobucket.com/albums/a1...g?t=1290107834


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