Project "Save the Flea!" Winter beater: 2007 Civic 1.8L, 5-speed

[Xist]

I love how one side is brown while the other is black!

[MetroMPG]

Originally Posted by Daox

Woo, lookin good!

How do you go about attaching the plastic to the cardboard?

Nothing fancy: commercial grade garbage bag plastic duct taped over the cardboard. Heat gun shrinks the plastic to take out wrinkles. (I haven't heat-gunned the Kammback yet. Thus its wrinkles.)

The top section of the tail is black coroplast though.

[MetroMPG]

With the colour/materials masked by fresh snow, it sure looks like it's supposed to be there, doesn't it?

Like a plus-sized 2nd generation Insight.

[awcook]

I don't know about you, but I like this Kammback better than the Insight's. I don't know why, it just looks a lot better.

[MetroMPG]

Tuft testing the boat tail video: this weekend.

[MetroMPG]

So, I was probably right that the side curvature is too aggressive, but some of the flow problems on the lower side originate BEFORE the tail...



With apologies to the colour blind...

• GREEN TUFTS = smooth flow or mildly turbulent
• YELLOW TUFTS = moderate turbulence, but no recirculation (tufts pointing "backward")/separation
• ORANGE TUFTS = high turbulence and some recirculation (tufts pointing "backward")/separation
• RED TUFTS = permanent recirculation/separation

I'm debating doing some reconstructive surgery to reduce the curvature of the lower side panel (ie. increase the width of the "transom" / rear tail light panel).


But the problem with the flow on the lower side portion is it's not getting clean air off the side of the bumper behind the rear wheel. The air there is already highly turbulent with some recirculation/separation. So relaxing the tail curvature downstream of that isn't really going to help much on its own.

[MetroMPG]

I think tomorrow morning I'm going to make a quick 'n' dirty cardboard fender skirt and repeat the tuft test. Maybe it'll clean up the flow enough to let the side of the tail do its job.

I knew there was a reason I left the "camera boom" in the tail this afternoon...

[Xist]

Would you say the black is more or less what you have now? What if you added a few layers of cardboard, sliding each one forward to match the curve the best you can (red), although you would still want to fill the gaps (pink).

Will you please tell us about the taillights, etc?

[MetroMPG]

Yup Xist, that's pretty much what I have, except the tail surfaces are curved instead of straight.

---

I mocked up a CAD* fender skirt and did another quick tuft test.



It seemed to do the trick!

Aside from the area of deepest curvature in the transition from skirt-to-tail (green circle), there's now little or no recirculation in the tufts compared to before. Plenty of turbulence, oh yes, but the airflow is now going the right direction:



(* Cardboard Aided Design)

[MetroMPG]

Originally Posted by Xist

Will you please tell us about the taillights, etc?

Sure! They're tail lights off a Swift GT parts car:



I modified 'em...



And they connect to the car's trailer lights harness. At some point I want to get a pic of the rear of the car all lit up.