MetroMPG's Honda Insight boat tail extension (cardboard) tuft video; ABA test +9.7%

[Xist]

Originally Posted by MetroMPG

You know, it looks like the sides curve more than the top. Could you cut panels of varying lengths and laminate them from the back to the front? Like leaf springs!



I would put the shortest piece on the inside and put longer and longer strips going out, or cover the edges with paper maché. You want a smooth edge for aerodynamics, right?

We want smooth edges because it is beautiful!

[ultimx]

Idk if u already see this or not but it does look like the second half of the side should follow the first half of the angle of curvature maybe to the middle of the tail light and not to the inside of it (I'm sure u already see that)? Can't wait to see what u do next, gives me ideas as to what to try for my tail. Thanks for the pics, helps everyone out including me!

[cRiPpLe_rOoStEr]

Want a cheap weatherproofing? Stickerbomb it

[NeilBlanchard]

Looking forward to the video - but from the still image it looks like the tufts on the top are slightly angled to ward the center, which would indicate the air is flowing up from the sides and over the top? So, you are likely correct that the sides are curved too much.

[AndrzejM]

I just got a notification e-mail of Neil's reply to the thread and it hit me when I've read the name of the thread again... If this is "quick 'n' dirty" boat tail then all others boat tails are what?
I'm just so impressed by your craftsmanship Metro! Congrats again on fabricating such incredible boat tail from a piece of cardboard.

[MetroMPG]

Well, after a good night's rest and a fresh look at the tuft testing results today, I've decided it's good enough as-is. I'm not going to change it.

EDIT: Neil, I might just test that wheel strake/boattail idea to reduce turbulence, too. If that doesn't help, when I make the permanent tail, I'll use a little less curvature in the sides, which will add about 20 cm / 4 in. to the width of the rear.

Tuft testing video: (used Youtube's "image stabilization" feature, which is fantastic! The raw video is pretty bumpy at times.)

http://www.youtube.com/watch?v=TmEeiGZwmS8

Next task: A-B-A test and weather-proof it. Weigh it, measure it, to answer those inevitable questions.

[3-Wheeler]

Originally Posted by MetroMPG

Hi Darin,

Hey, I noticed that you used a camera this time instead of the web-cam. Is there a reason why you chose the camera?

A nice zoom picture from the side would be helpful when you can get to it. Your down-slope is slightly less severe than mine, and those tufts seem to be very steady in that area. Getting a better view of your sloping angle would be interesting.

Just a side note, but have you tried mounting the camera on a shorter length support, and viewed the tufts at a "flatter angle". All the tufts would still be placed in the "perspective" view, but would have less worries of hitting the camera on something to the side of the road.

I'm asking questions for education when I try a tuft test on the tail.

__________

That's some really fancy cardboard fashioning !! Very impressive !!

Thanks, Jim.

[MetroMPG]

Hi Jim...

Originally Posted by 3-Wheeler

you used a camera this time instead of the web-cam. Is there a reason why you chose the camera?

The web cam I had been using died. Plan B: I got an eBay replacement, but it was junk. Plan C was to borrow a GoPro type digital movie camera with a wide angle lens, but that didn't work out either. Plan D was the regular digital camera set in movie mode. It worked OK, and has better image quality (than the web cams). Downside: not as convenient as a web cam, which I could monitor from inside the car to make sure it was working/review footage to make sure it was clear.

A nice zoom picture from the side would be helpful when you can get to it.

Sure!

Just a side note, but have you tried mounting the camera on a shorter length support

I did look at a few different angles, and I just liked this one best. Where I tested, there was no chance of hitting the boom on anything. A GoPro wide-angle camera would have permitted a shorter boom, and still given me the angle I liked.

Can you answer me a question -- how wide is your tail's "transom" / rear surface? EDIT: never mind - found the answer in your tail thread.

[MetroMPG]

Originally Posted by Xist

cut panels of varying lengths and laminate them from the back to the front? Like leaf springs!

That's a creative idea, by the way!

[Xist]

Originally Posted by MetroMPG

That's a creative idea, by the way!

Yay! I am useful!