ID this wing?
06-16-2011, 04:44 AM
#10
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high angle of attack with a cheap wing (or any wing) = lots of drag and no downforce.
quoted from one of those out there who knows much more about these things than I do, and who was the 2010 Superlap Champion in mod:
"Actually, if the wing is so steep that it is in stall effect, it will not give any DF but only drag. Wings require attached airflow over and under to work, spoilers only use the air over the top."
And from Kognition (mfg of sick wings):
"stalling might feel like some measure of downforce in the car. But it will take some significant HP away from your motor. You could lose 50 HP easily on a stalled wing that is too steep."
I'll add to that just that the whole airflow over and under being the key to creating downforce without ridiculous amounts of drag is exactly why cheap wings are such a gamble - the radius of the front edge, the shape, etc. are so crucial for it to be effective, and there's no way to verify any of that prior to buying a wing off ebay.
OP: straight wing needs to be in clean air to be effective, so assuming the shape is good, you need to mount it very high.
-Ryan
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06-16-2011, 09:48 AM
#12
gotta chime in because I've been reading up on wings and don't want to see others getting false info/wasting time or money.
high angle of attack with a cheap wing (or any wing) = lots of drag and no downforce.
quoted from one of those out there who knows much more about these things than I do, and who was the 2010 Superlap Champion in mod:
"Actually, if the wing is so steep that it is in stall effect, it will not give any DF but only drag. Wings require attached airflow over and under to work, spoilers only use the air over the top."
And from Kognition (mfg of sick wings):
"stalling might feel like some measure of downforce in the car. But it will take some significant HP away from your motor. You could lose 50 HP easily on a stalled wing that is too steep."
I'll add to that just that the whole airflow over and under being the key to creating downforce without ridiculous amounts of drag is exactly why cheap wings are such a gamble - the radius of the front edge, the shape, etc. are so crucial for it to be effective, and there's no way to verify any of that prior to buying a wing off ebay.
OP: straight wing needs to be in clean air to be effective, so assuming the shape is good, you need to mount it very high.
-Ryan
high angle of attack with a cheap wing (or any wing) = lots of drag and no downforce.
quoted from one of those out there who knows much more about these things than I do, and who was the 2010 Superlap Champion in mod:
"Actually, if the wing is so steep that it is in stall effect, it will not give any DF but only drag. Wings require attached airflow over and under to work, spoilers only use the air over the top."
And from Kognition (mfg of sick wings):
"stalling might feel like some measure of downforce in the car. But it will take some significant HP away from your motor. You could lose 50 HP easily on a stalled wing that is too steep."
I'll add to that just that the whole airflow over and under being the key to creating downforce without ridiculous amounts of drag is exactly why cheap wings are such a gamble - the radius of the front edge, the shape, etc. are so crucial for it to be effective, and there's no way to verify any of that prior to buying a wing off ebay.
OP: straight wing needs to be in clean air to be effective, so assuming the shape is good, you need to mount it very high.
-Ryan
That's fine and all, but also misleading. Yes drag will increase. But it really depends on the track and your power level. You can overcome the drag and have a net reduction in lap time even though it's not technically working as a wing. Case in point.
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06-16-2011, 03:05 PM
#14
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That is entirely different from a spoiler. The spoiler doesn't allow air under it, and so functions completely differently. It is of course known that a spoiler such as that creates significant drag, but it also creates downforce. Moti had much more than stock power and was able to used that spoiler effectively.
I don't think a wing at a steep angle would function like a spoiler. More likely just an air brake.
Last edited by ThePass; 06-16-2011 at 03:18 PM.
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06-16-2011, 03:22 PM
#15
I'll take all the wind generated drag possible if it resulted in a faster car. Is it worth a $100 throwaway risk if you could potentially drop a second at your local track?
This is miata turbo, why are you talking about stock power?
Repeat:
But it really depends on the track and your power level. You can overcome the drag and have a net reduction in lap time even though it's not technically working as a wing.
This is miata turbo, why are you talking about stock power?
Repeat:
But it really depends on the track and your power level. You can overcome the drag and have a net reduction in lap time even though it's not technically working as a wing.
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06-16-2011, 03:44 PM
#16
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The discussion in this thread is about a wing.
You claimed that you could take that wing and mount it at a steep angle to get some downforce. This is not true - and I pointed that out. A wing that is raised off the trunk at a steep angle will not produce anything other than drag.
Then you started talking about spoilers - which is a flap mounted to the trunk surface. Apples to Oranges. Not the same thing. Nobody including myself is arguing that a spoiler is not effective - heck, NASCAR is on my TV right now and they are all using spoilers. We know those work. They create lots of drag, but also downforce - so if you have the power to overcome the drag, a spoiler can produce faster lap times.
You're saying you'd gladly take on drag if it will also drop your lap time. I think everyone would. BUT, a wing at too steep of a an angle won't function the way a spoiler does. It will ONLY create drag and will NOT produce downforce. Therefore a steep wing will not take time off of your lap.
Are you understanding the differentiation I'm trying to point out between spoiler and wing? They are not the same, and a wing will not turn into a spoiler just by puting it at a steep angle.
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06-16-2011, 04:36 PM
#18
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Zero? Probably not, but such a negligible amount that it has zero real-world benefit. A plane falls out of the air when it stalls - maybe the wing is still doing a little bit - but not enough for it to count.
Do you know how a wing works, and very importantly, in comparison, do you know how and why a spoiler works? It's not the air hitting the spoiler that's creating the downforce. That's a misconception. If you thought that the air hits the spoiler which then pushes the rear downwards (which is not correct), then I can see how you could then assume that the same effect could be seen from a wing off the decklid at a steep angle.
Just to get all the correct info into this thread, and to be thorough, I'll try to briefly cover all the basics about wing vs. spoiler, hopefully that may clear up whatever part there's a misunderstanding about..
How a wing works:
On an airplane - due to wing shape, air passes over the wing faster than it passes under it. This creates lift.
On a car - the wing shape is flipped upside down. Now the air passes under the wing faster than it passes over it. This creates force that pushes the wing down. This force is transferred through the wing struts to the rear of the car, pushing it down.
How a spoiler works:
The whole car is an airfoil. This is why flat-bottom undertrays are effective. If you can get the air to travel under the car faster than it is traveling over the car you create the same effect as you do with the wing - the car is pushed downwards.
A spoiler "spoils" the air - it slows down the air running over the car. Slower air over the car, faster air under the car = downforce.
Why a wing can't work as a wing when at a steep angle:
Too steep of an angle creates a "stall effect" where the air passing under the wing cannot stay attached to the bottom of the wing because it is too sharp of an angle. So, you lose that airspeed differential between top and bottom of the wing surface. Therefore you lose the downforce and only create drag - more drag as the angle increases.
Why a wing can't work as a spoiler when at a steep angle:
A wing is raised off of the trunk surface. Therefore, no matter what angle you set it to, all of the attached air that is passing over the car is unaffected by the wing - that air is passing under the wing. Therefore, it does not change the over-the-car airspeed. So you do not get any of the effect of a spoiler.
This is why a steep wing is just an airbrake - it creates drag and does not create downforce.
Sometimes you'll see a race car that has both a spoiler lip on the trunk, and a wing. The spoiler is slowing down the attached airflow over the car - which, especially in conjunction with an undertray, makes the entire car itself a more effective airfoil, creating more downforce on the car itself. The wing creates it's own downforce and transfers that force into the rear of the car.
Do you know how a wing works, and very importantly, in comparison, do you know how and why a spoiler works? It's not the air hitting the spoiler that's creating the downforce. That's a misconception. If you thought that the air hits the spoiler which then pushes the rear downwards (which is not correct), then I can see how you could then assume that the same effect could be seen from a wing off the decklid at a steep angle.
Just to get all the correct info into this thread, and to be thorough, I'll try to briefly cover all the basics about wing vs. spoiler, hopefully that may clear up whatever part there's a misunderstanding about..
How a wing works:
On an airplane - due to wing shape, air passes over the wing faster than it passes under it. This creates lift.
On a car - the wing shape is flipped upside down. Now the air passes under the wing faster than it passes over it. This creates force that pushes the wing down. This force is transferred through the wing struts to the rear of the car, pushing it down.
How a spoiler works:
The whole car is an airfoil. This is why flat-bottom undertrays are effective. If you can get the air to travel under the car faster than it is traveling over the car you create the same effect as you do with the wing - the car is pushed downwards.
A spoiler "spoils" the air - it slows down the air running over the car. Slower air over the car, faster air under the car = downforce.
Why a wing can't work as a wing when at a steep angle:
Too steep of an angle creates a "stall effect" where the air passing under the wing cannot stay attached to the bottom of the wing because it is too sharp of an angle. So, you lose that airspeed differential between top and bottom of the wing surface. Therefore you lose the downforce and only create drag - more drag as the angle increases.
Why a wing can't work as a spoiler when at a steep angle:
A wing is raised off of the trunk surface. Therefore, no matter what angle you set it to, all of the attached air that is passing over the car is unaffected by the wing - that air is passing under the wing. Therefore, it does not change the over-the-car airspeed. So you do not get any of the effect of a spoiler.
This is why a steep wing is just an airbrake - it creates drag and does not create downforce.
Sometimes you'll see a race car that has both a spoiler lip on the trunk, and a wing. The spoiler is slowing down the attached airflow over the car - which, especially in conjunction with an undertray, makes the entire car itself a more effective airfoil, creating more downforce on the car itself. The wing creates it's own downforce and transfers that force into the rear of the car.
Last edited by ThePass; 06-16-2011 at 04:55 PM.
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06-16-2011, 05:00 PM
#20
"At low/mid speed it's probably worth the price if it's under $100 and you give it a high angle of attack."
I based this on actual experience seeing various ebay wings at the track, they often don't mount to the miata trunk with a high enough angle of attack.
Sure it's a general statement, but we're talking about a wide range of typically inefficient airfoils that probably produce more drag than a well designed $600+ wing. At low/mid speed (under 110mph) a lowly greddy'd miata likely produces enough power to overcome any possible drag a rear ebay airfoil will produce at 25* or even 45*.
You keep saying stuff like this, but it's simply untrue.
"This is why a steep wing is just an airbrake - it creates drag and does not create downforce. "
Notice I didn't give a specific angle of attack or mounting method? That depends on the airfoil, the car itself, traffic, racing near walls? This depends on testing. Even if you buy a 949 racing wing you'll still need to set it up specifically for you in your car at your track.
If the lift coefficient for a wing at a specified angle of attack is known (or estimated using a method such as thin-airfoil theory), then the lift produced for specific flow conditions can be determined using the following equation:
where
L is lift force,
ρ is air density
v is true airspeed,
A is planform area, and
CL is the lift coefficient at the desired angle of attack, Mach number, and Reynolds number[48]
This equation is basically the same as the drag equation, only the lift/drag coefficient is different.
So.. yes. it's probably worth the price if it's under $100
I based this on actual experience seeing various ebay wings at the track, they often don't mount to the miata trunk with a high enough angle of attack.
Sure it's a general statement, but we're talking about a wide range of typically inefficient airfoils that probably produce more drag than a well designed $600+ wing. At low/mid speed (under 110mph) a lowly greddy'd miata likely produces enough power to overcome any possible drag a rear ebay airfoil will produce at 25* or even 45*.
You keep saying stuff like this, but it's simply untrue.
"This is why a steep wing is just an airbrake - it creates drag and does not create downforce. "
Notice I didn't give a specific angle of attack or mounting method? That depends on the airfoil, the car itself, traffic, racing near walls? This depends on testing. Even if you buy a 949 racing wing you'll still need to set it up specifically for you in your car at your track.
If the lift coefficient for a wing at a specified angle of attack is known (or estimated using a method such as thin-airfoil theory), then the lift produced for specific flow conditions can be determined using the following equation:
where
L is lift force,
ρ is air density
v is true airspeed,
A is planform area, and
CL is the lift coefficient at the desired angle of attack, Mach number, and Reynolds number[48]
This equation is basically the same as the drag equation, only the lift/drag coefficient is different.
So.. yes. it's probably worth the price if it's under $100
Last edited by BenR; 06-16-2011 at 05:13 PM.
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