The downward slope of the top area of the tail extension was looking, at least to my eye, slightly 'low' in appearance for some reason. Maybe it was just a hunch, but something did not look right after the build up to this point.
After discussing the Aerohead Streamlining Template at length in this thread, it was time to start getting some numbers to check on the current state of the top angle.
The car was dropped from it's jacks to the garage floor to start collecting some data.
This picture shows the car sitting level, and a bubble level placed at the extreme tail of the build.
This particular bubble level can display incline, and that's what I was most interested in. Just how much slope did the tail rest at? It was time to know since Aerohead has mentioned that it should not exceed 22°. What was the angle?
This picture shows the news. It's currently sitting at 20°, which at this length from the maximum cordal height seemed too steep to me! I already accounted for the slight slope of the garage, which was only 1°.
And to top it off, I had more length to add, which would make the angle even greater! This would not do!
So drastic measures all called for!!!
The black dots show the intended cut path!! No!! Yes!!
Oh, it's too late!! The cut is already started as shown by the hacksaw blade sticking out of the foam panel.
Wow, what a picture! The car looks slightly naked without all that foam.
Here is the same piece glued back in place, but 0.5 inches higher at the trailing edge. This essentially makes the 'angle', straight with no curvature.
Now the remaining open area is closed in.
Here's a detail shot showing the many pieces needed to fill in small areas.
More filling by the rear tire.
And the 'gap' filled in with spackling.
At this point, something was still bugging me and the only way to determine exactly what it was, would require rolling the car out of the garage and getting a telephoto picture of the car with the tail extension in place.
Now place the car in the CAD program to try and figure out how things shaped up!
Unfortunately the CAD program seems to distort this particular zoom compared to making the car larger on the screen. However this view clearly shows the Aerohead Streamlining Template curvature in BLUE and the modified Honda Insight curve fit in green.
You can see that Honda decided the air could still stay attached with a much more aggressive initial curvature compared to the Template.
I have compensated for the driveway angle in this CAD view.
What does all this show?
That the Honda, as well as the Prius, all seem to deviate from the Template during the initial curve at the max cordal height.
Looking at the CAD view still makes me glad that I raised the tail end of the extension slightly. It gets it closer to the Template in overall shape.
Now the small hatch is ready to mount to the tail extension. Shown here are small wood pieces being used to align and hold the hatch in place, so that the latch can be embedded into the extension.
Here's a shot showing the latch from the inside of the extension. You can also see how the fiberglass is trimmed away in this area.
A close view showing how much foam was cut out to allow insertion of the hatch in this area.
And here's a shot from the other side.
Finally, a picture showing small pieces of foam glued into the opening from the initial cut.
Jim.
Today
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