How well do you think this would work?

[jrscteg]

So what your saying is angle it down to the "b" position for the most effect?

[kach22i]

Automobile 2 - Odds and Ends pictures by kach22i - Photobucket


I'm saying that following the template is best for aero, always.

In addition (open to debate - just my two cents), going with a 10, 20, or even 30 degree angle may be even more effective than following the template. However you invite uplift.

My point of this being a FWD car, and if not adding down-force to the front, you would not want to add or subtract very much force from the rear.

I think the original image (not my side view) is at a slightly up angle (see yellow line above) than template perfect. However the tiny amount of down-force here may in fact be equal to any chin spoiler and or splitter down-force we are not seeing from this rear angle photo.

[euromodder]

Stay well clear of 28-30 degrees down - it's the angle of aerodynamic death ...

[cfg83]

euromodder -

Originally Posted by euromodder

Stay well clear of 28-30 degrees down - it's the angle of aerodynamic death ...

I agree. If I start with this template :



Then do a quick and dirty 3-part breakdown :



As you see, the 3-part breakdown shows 21+ degrees max in the last portion of the tail. Only full boattails will ever use this angle, and it's still much less than 28 degrees.

From the above, the "average" angle is about 14 degrees. The angle near the start of the boattail is shallow, like a Honda Fit. The longer the kammback, the greater the angle, tapping out at about ... 15 degrees max.

CarloSW2

[aerohead]

If you'll go to the FLOW-IMAGES thread,there's a photo of a Golf/Rabbit in VW's wind tunnel with smoke being injected into the turbulent wake.
I think that the wake behind the Civic is going to be the same,with,or without the roof extension.
As Frank Lee has mentioned,closing in the sides would help,then you'd have the integration for some boat tail behind.
You've got to extend the body rearward to see any significant drag reduction.
For the drag races,the Kamm extension would help clean up the air, helping the drag chute to inflate.