Rear spoilers........

[MetroMPG]

I think wood is ideal for a lip extension (flexible for the size you'll need, relatively easy to work/shape).

Maybe start with a piece of quarter-round trim, shape, shave & sand it to your liking, then coat it with polyester fiberglass resin to weatherproof it. Sand & paint. Install.

Have you verified you've got attached flow at the trailing edge of the trunk without the OEM wing?

There's a small chance that the OEM "wing" could have been good for aero if the deck lid is a bit too low to attain reattachment. The upper wing surface may have been where that was happening.

Before investing the effort in the lip spoiler, I'd want to know for sure.

[MetroMPG]

Correction: I was wrong with "quarter round". The shape I was thinking of is the same as the bottom 2 in this image:



Not sure what that's called.

[GasSavers_brick]

Originally Posted by MetroMPG

There's a small chance that the OEM "wing" could have been good for aero if the deck lid is a bit too low to attain reattachment. The upper wing surface may have been where that was happening.

Before investing the effort in the lip spoiler, I'd want to know for sure.

Haven't done it yet, but you're absolutely right. I can't take video, but I did find a way to rig my digital camera and laptop to take stills automatically while I'm doing a test run with tufts on the lid. If I don't have attached flow I'll put the factory wing/spoiler/whatever back and re-test. Maybe I'll get around to it tomorrow?

[SVOboy]

Do you have holes in your poor hood without the factory wing on there?

[GasSavers_brick]

Nope, I installed plugs made from painted carriage bolts sealed with rubber fender washers. It's not ideal but it works well.

[lovemysan]

Originally Posted by MetroMPG

Correction: I was wrong with "quarter round". The shape I was thinking of is the same as the bottom 2 in this image:

<IMG style="; WIDTH: expression(this.width > 800 ? 800: true); max-width: 800px" alt="" src="http://www.oldershaws.com/images/profile1.jpeg" border=0>

Not sure what that's called.

Thats cove round I believe

[ZugyNA]

From the MiniCooper science fair project: (pdf abstract)

"From research, I found that most of the drag on the car is related to how the air comes off the back of the
car. This separated flow creates a partial vacuum that is responsible for most of the drag. By creating
attachments, I found I could make that area of separated flow smaller. A good visualization of this is the
process of narrowing the wake of a boat. My first attachment design consisted of two vertical wings
attached at the back sides of the car and curved inward, which narrowed the flow. My second design was
one wing down the center. This resulted in increasing the drag instead of lowering it. Several other
designs were tested, but they had little effect on the drag. The results I collected in the wind tunnel
supported the results I got from testing the set up on the car. My first attachment design was the most
successful and it reduced the total drag by 12.5%."

[MetroMPG]

Originally Posted by ZugyNA

My first attachment design consisted of two vertical wings
attached at the back sides of the car and curved inward, which narrowed the flow.

AKA a partial boattail. Neat. Too bad no pics in the PDF.

Also I suspect the author meant "angled inward" instead of "curved inward". But I could be wrong.

[ZugyNA]

But these verticals seem to be pointing outward?

http://www.max-mpg.com/html/tech/main.htm

Probably has to do with the shape of the body work in front of it?

Looks like they act like LARGE vortex generators?

Bunch of small vgs or 2-3 large ones (wings)?