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Old 03-30-2012, 05:04 AM   #24 (permalink)
Master EcoModder
Join Date: Apr 2011
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ZX - '97 Citroen ZX Monaco
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Originally Posted by euromodder View Post
What is even more surprising is the fact that the 2° diffusor helps.

On this kind of station-wagon-like rear ends - no diffusor at all ( 0° ) was found to offer the lowest drag, with a cavity, the diffusor helps another 6%.

A rear cavity is something that I could easily fit on Hägar.
A bit of foam and double-sided tape will do.
It is not very box like when you look at the roofline, for me it looks like more of hatchback etc from rear roof section.

With addition of rear cavity it is more like boxed from rear. Before cavity they used 7 degree diffusor, but with cavity 2 degrees was optimal, so if I'm not horribly misreading that would also tell that they did move from coupe/hatchback to boxed end, however it is much smaller boxed end.

High side window line and blunt front are perhaps what makes illusion of car being box shaped, sides are also rather straight down and it is relatively tall compared to width, but if one photoshops everything under window line away it is not boxed station wagon shape at all and what affect to diffuser angle is how upper side, roof, trunk lid etc are angled from top, afaik.

This should make it easier to see how it is not station wagon kind of shape at all (extract from document mentioned in 1st post):

That is one of the pits easy to fall with aeromodding, they use lot of tricks with cars that cheat eye, to see true shape and form sometimes one needs to take photo and edit it a bit.

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