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Old 10-13-2012, 05:43 AM   #66 (permalink)
AndrzejM
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Join Date: Oct 2011
Location: Poland
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Berta - '97 BMW 318 tds Compact
90 day: 62.03 mpg (US)

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90 day: 37.58 mpg (US)

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Quote:
Originally Posted by MetroMPG View Post
Forgive me if you already covered this:

But does flow off the roof re-attach on the trailing edge of the hatchback's horizontal "deck lid" area? Did you ever tuft test that before adding the kammback?

That horizontal section looks too short, which would make re-attachment less likely. If that's the case, Kammy has the potential to make a significant improvement, as the coast down numbers suggest.
Yes it is too short, and that's why Compact has the highest Cd, from the whole E36 series Cd=0,34 (the same as a station wagon) - aee attachment. I wanted to have a hatchback though, because it's the most practical car for me, and it weights less than other models.

Anyway, kammback seem to work as I hoped for so I need to build a final and permanent version now.

My friend who saw my YT video from tuft testing said that Berta looks funny, more like BMPrius than BMW

Piwoslaw: I wanted to measure Cd but since my car is waydifferent from stock version according to reduced weight I need to weight her first. Maybe I'll go to local junkyard and ask guys there to weight Berta for me.
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The Following 2 Users Say Thank You to AndrzejM For This Useful Post:
MetroMPG (10-13-2012), WesternStarSCR (10-16-2012)