New Wing to Test
11-27-2012, 01:12 AM
#62
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I don't see anything wrong with using a practice wing. If they've got tethers, they're the real thing regardless of provenance. I think there's a sticker on the wing as well showing that it's race-legal. Great deal, Ryan. Does your source have more?
About the Gurney flaps (aka wickerbills) on the COT wing - you can use standard aluminum angle. I forget what size, but I had one that slipped right in. My wing came with the flap removed.
Some of the end plates are actually aerofoil shaped. Obviously not the best choice for someone who wants to turn right. It wouldn't be hard to build your own flat end plates although you'll give up about two inches of span that way. One interesting note on mine was this little wickerbill on one end plate.
About the Gurney flaps (aka wickerbills) on the COT wing - you can use standard aluminum angle. I forget what size, but I had one that slipped right in. My wing came with the flap removed.
Some of the end plates are actually aerofoil shaped. Obviously not the best choice for someone who wants to turn right. It wouldn't be hard to build your own flat end plates although you'll give up about two inches of span that way. One interesting note on mine was this little wickerbill on one end plate.
When I removed the carbon gurney on mine I had that very thought - that it seemed like 1/16" aluminum angle would slide right in there as a replacement if one wanted to try different gurney sizes or needed to replace it. That's good info.
The version I got had traditional endplates - I was careful to not get one of those with the molded ends, because then you lose airfoil width by removing them to run your own. I can't quite tell from your pictures, it looks like you are using the COT endplates, and that they might have airfoil extensions molded into them? Is that the case and what is the overall width of yours with endplates/without? Mine is 54" for the airfoil itself, and the endplates aren't part of the airfoil width so I don't lose width by making new endplates.
-Ryan
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11-27-2012, 09:37 AM
#63
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This guy has 4 of them - but like Ryan says, he's asking the ave at $525
NASCAR RACE USED CARBON FIBER WING WITH TEATHERS AND REMOVABLE END PLATES COT | eBay
NASCAR RACE USED CARBON FIBER WING WITH TEATHERS AND REMOVABLE END PLATES COT | eBay
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11-27-2012, 11:57 AM
#64
The version I got had traditional endplates - I was careful to not get one of those with the molded ends, because then you lose airfoil width by removing them to run your own. I can't quite tell from your pictures, it looks like you are using the COT endplates, and that they might have airfoil extensions molded into them? Is that the case and what is the overall width of yours with endplates/without? Mine is 54" for the airfoil itself, and the endplates aren't part of the airfoil width so I don't lose width by making new endplates.
-Ryan
-Ryan
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11-27-2012, 03:13 PM
#65
This guy has 4 of them - but like Ryan says, he's asking the ave at $525
NASCAR RACE USED CARBON FIBER WING WITH TEATHERS AND REMOVABLE END PLATES COT | eBay
NASCAR RACE USED CARBON FIBER WING WITH TEATHERS AND REMOVABLE END PLATES COT | eBay
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11-27-2012, 10:45 PM
#67
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I wonder how many of these are out there in the world... seems like a decent supply, but they aren't making them anymore, and probably didn't make all that many.
-Ryan
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11-28-2012, 12:21 AM
#70
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Here is more info than you would ever want to know on the Liebeck (M06-13-128) and many others:
http://www.ae.illinois.edu/m-selig/u...il-Data-V2.pdf
I am glad you asked this question because the above database has been offline for some time now...glad to see it's back.
http://www.ae.illinois.edu/m-selig/u...il-Data-V2.pdf
I am glad you asked this question because the above database has been offline for some time now...glad to see it's back.
To make info/data easily retrievable for everyone - I know Andrew asked - I have taken some screenshots of the pages which are relevant and added the descriptions of the pages taken from the table of contents:
*pics removed because they were of the wrong airfoil - see rlogan's post below for correct ones*
The "Liebeck Airfoil" was designed by Bob Liebeck.
Liebeck’s thesis was titled “Optimization of Airfoils for Maximum Lift,” a topic suggested by Ormsbee and the late A.M.O. Smith of Douglas, who encouraged him to continue the research. The revolutionary devices are now called “Liebeck airfoils” in the industry. Originally designed in the ‘70s for high altitude airplanes, a Liebeck airfoil will be used in the NASCAR Car of Tomorrow scheduled to be unveiled this year.
In his spare time, Liebeck has designed wings for Indianapolis 500 and Formula One racing cars, the keel for the yacht that won the America’s Cup in 1991 and the wing for a World Championship acrobatic airplane, an unmatched triple crown. “This could be summarized as victory on land, sea and air,” he said.
In his spare time, Liebeck has designed wings for Indianapolis 500 and Formula One racing cars, the keel for the yacht that won the America’s Cup in 1991 and the wing for a World Championship acrobatic airplane, an unmatched triple crown. “This could be summarized as victory on land, sea and air,” he said.
-Ryan
Last edited by ThePass; 11-29-2012 at 11:58 PM.
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11-28-2012, 11:07 AM
#71
It's early days, I'm going to do some testing to see what the airflow looks like in that region of the car and play with angles. Once I've got those points figured out, I might play with end plate size to see what effect it has. I figure these end plates were good enough for the original NASCAR application, so they'll probably work well enough for now.I should be able to pull my wing and mounts off the car today to send to Paco. He'll take measurements and should be able to cut out some copies pretty quickly. If you're potentially interested in one, drop me a line at keith@flyinmiata.com. If I can come up with a good measurement location so we can pass the numbers to him, he should also be able to adjust the mounting position up/down and back/forward if you prefer.
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11-28-2012, 10:30 PM
#73
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Relax, it's not a dick measuring contest It's early days, I'm going to do some testing to see what the airflow looks like in that region of the car and play with angles. Once I've got those points figured out, I might play with end plate size to see what effect it has. I figure these end plates were good enough for the original NASCAR application, so they'll probably work well enough for now.
It's early days, I'm going to do some testing to see what the airflow looks like in that region of the car and play with angles. Once I've got those points figured out, I might play with end plate size to see what effect it has. I figure these end plates were good enough for the original NASCAR application, so they'll probably work well enough for now.
But you're of course already thinking the same 
I'm excited to see this airfoil getting some proper R&D on a few miatas now. Can't wait to be doing some of my own soon.-Ryan
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11-29-2012, 04:19 PM
#74
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I misspoke on the airfoil ID. There have been several Liebeck designs through the years and the COT is one of the newer ones. It is similar to the predator airfoils.
It looks to be something along the lines of:
LNV109A
LNV109A (lnv109a-il)
If you want to play around with it in javafoil, here:
JavaFoil - the Applet
And you can get the coordinates here:
UIUC Airfoil Data Site
There is a "geometry" tab on the applet where you paste in these coordinates and select "update view".
Once you have the coordinates in you can go to the "Flowfield" tab change angle of attack and run an analysis to get Cl/Cd Re numbers. I usually turn on "colored field" and "Streamlines"
See attached sample at 10 degrees AOI...of course this assumes clean air which is never the case behind a race car. It will let you compare different airfoil designs and their efficiency.
It looks to be something along the lines of:
LNV109A
LNV109A (lnv109a-il)
If you want to play around with it in javafoil, here:
JavaFoil - the Applet
And you can get the coordinates here:
UIUC Airfoil Data Site
There is a "geometry" tab on the applet where you paste in these coordinates and select "update view".
Once you have the coordinates in you can go to the "Flowfield" tab change angle of attack and run an analysis to get Cl/Cd Re numbers. I usually turn on "colored field" and "Streamlines"
See attached sample at 10 degrees AOI...of course this assumes clean air which is never the case behind a race car. It will let you compare different airfoil designs and their efficiency.
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11-29-2012, 11:57 PM
#75
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I was in the garage today and took a look at the profile of the airfoil and was going to come into this thread and say that it doesn't look like that earlier Liebeck airfoil, but you beat me to that with the proper info, thanks!
I will edit out the screenshots I posted above of the other Liebeck design so that people don't get confused.
I actually came across the Predator airfoils last night, which is a really killer looking wing. You're right, the COT looks quite similar to it.
Lift/Drag data for airfoils always assumes clean air I would think... this way you can compare apples to apples between different airfoils.
I played with JavaFoil a bit. Really cool to see the differences at different angles of attack.
-Ryan
I will edit out the screenshots I posted above of the other Liebeck design so that people don't get confused.
I actually came across the Predator airfoils last night, which is a really killer looking wing. You're right, the COT looks quite similar to it.
Lift/Drag data for airfoils always assumes clean air I would think... this way you can compare apples to apples between different airfoils.
I played with JavaFoil a bit. Really cool to see the differences at different angles of attack.
-Ryan
Last edited by ThePass; 11-30-2012 at 12:11 AM.
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11-30-2012, 09:10 AM
#76
Thinking out of the box, would there be an advantage to the aero at the back of the car if they pushed or pulled air together or apart by reversing one of the airfoils? I know they are formed CF so a mold 'negative' would need to be made. Would you want to increase the pressure to fill the void back there or pull more air out? 
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