Most Effective Wing?
01-04-2011, 02:27 AM
#46
Rennlist Member
the discount of a good wing and a so so wing is a good one! why, because downforce is downforce. (or lift if its on an airplane VR and 3333)
the difference will be almost negligable, even in extreme cases. what, you might get 250lbs of downforce at 120mph with 25lbs of drag with one (CORRECTED to match L/D of 10:1 as was originally mentioned), and a bad wing for this application might have 28lbs of drag? at that speed, its effect is about 3hp. Sure, if you have time, investigate the options. the new compound wings are designed for different shaped tops of cars for optimial and consistant lift across the wing. this allows for better drag numbers too, but at the speeds we travel at, you are shaving hairs. I think at laguna, we have an aveage speed of 85mph or something with top speeds for only a couple of seconds of 130mph, maybe. the turns are in the 80mph range and there is only a little bit of help with wings here. willow springs, a lot more, but it depends on the track. the guy that spends a ton of time reserching the wing characteristics, will probably set the wing and never touch it again for several track outings.
I did some experimenting with and without a wing. (actually a good wing and a modified stock spoiler/wing). the results in feel were not that big and lap times although on smaller tires, crummier tires, and not really pushing hard were pretty close to my best. only in a few places did i feel a little naked without the real wing out back. sure, wings work, but the differences between versions are not that great.
the difference will be almost negligable, even in extreme cases. what, you might get 250lbs of downforce at 120mph with 25lbs of drag with one (CORRECTED to match L/D of 10:1 as was originally mentioned), and a bad wing for this application might have 28lbs of drag? at that speed, its effect is about 3hp. Sure, if you have time, investigate the options. the new compound wings are designed for different shaped tops of cars for optimial and consistant lift across the wing. this allows for better drag numbers too, but at the speeds we travel at, you are shaving hairs. I think at laguna, we have an aveage speed of 85mph or something with top speeds for only a couple of seconds of 130mph, maybe. the turns are in the 80mph range and there is only a little bit of help with wings here. willow springs, a lot more, but it depends on the track. the guy that spends a ton of time reserching the wing characteristics, will probably set the wing and never touch it again for several track outings.
I did some experimenting with and without a wing. (actually a good wing and a modified stock spoiler/wing). the results in feel were not that big and lap times although on smaller tires, crummier tires, and not really pushing hard were pretty close to my best. only in a few places did i feel a little naked without the real wing out back. sure, wings work, but the differences between versions are not that great.
You are assuming that buying a wing will have an impact on what I will spend on driver training. It won't.....
The suspension on my car is going to be quite good. Buying a wing isn't going to affect it's quality one way or another.
Aero is important and I think you are discounting the difference between a good wing and a so so wing. The CFD data in the absence of other data, is better than nothing.
Scott
The suspension on my car is going to be quite good. Buying a wing isn't going to affect it's quality one way or another.
Aero is important and I think you are discounting the difference between a good wing and a so so wing. The CFD data in the absence of other data, is better than nothing.
Scott
Last edited by mark kibort; 01-04-2011 at 04:19 PM.
01-04-2011, 03:27 AM
#47
Rennlist Member
the discount of a good wing and a so so wing is a good one! why, because downforce is downforce. (or lift if its on an airplane VR and 3333)
the difference will be almost negligable, even in extreme cases. what, you might get 250lbs of downforce at 120mph with 12lbs of drag with one, and a bad wing for this application might have 13lbs of drag? at that speed, its effect is about 2hp. Sure, if you have time, investigate the options. the new compound wings are designed for different shaped tops of cars for optimial and consistant lift across the wing. this allows for better drag numbers too, but at the speeds we travel at, you are shaving hairs. I think at laguna, we have an aveage speed of 85mph or something with top speeds for only a couple of seconds of 130mph, maybe. the turns are in the 80mph range and there is only a little bit of help with wings here. willow springs, a lot more, but it depends on the track. the guy that spends a ton of time reserching the wing characteristics, will probably set the wing and never touch it again for several track outings.
I did some experimenting with and without a wing. (actually a good wing and a modified stock spoiler/wing). the results in feel were not that big and lap times although on smaller tires, crummier tires, and not really pushing hard were pretty close to my best. only in a few places did i feel a little naked without the real wing out back. sure, wings work, but the differences between versions are not that great.
the difference will be almost negligable, even in extreme cases. what, you might get 250lbs of downforce at 120mph with 12lbs of drag with one, and a bad wing for this application might have 13lbs of drag? at that speed, its effect is about 2hp. Sure, if you have time, investigate the options. the new compound wings are designed for different shaped tops of cars for optimial and consistant lift across the wing. this allows for better drag numbers too, but at the speeds we travel at, you are shaving hairs. I think at laguna, we have an aveage speed of 85mph or something with top speeds for only a couple of seconds of 130mph, maybe. the turns are in the 80mph range and there is only a little bit of help with wings here. willow springs, a lot more, but it depends on the track. the guy that spends a ton of time reserching the wing characteristics, will probably set the wing and never touch it again for several track outings.
I did some experimenting with and without a wing. (actually a good wing and a modified stock spoiler/wing). the results in feel were not that big and lap times although on smaller tires, crummier tires, and not really pushing hard were pretty close to my best. only in a few places did i feel a little naked without the real wing out back. sure, wings work, but the differences between versions are not that great.
However I think you're sort of contradicting yourself to a degree in which you state certain absolutes and then pretty much say it's subjective and in the end not really substantial either way. Perhaps we're all kidding ourselves that at our speeds we need wings. Maybe it's all psychosomatic...but are you prepared to go back to a stock setup? Me either.
01-04-2011, 04:08 AM
#48
Race Car
Thread Starter
Mark,
I have seen that it is futile to argue with you.....
But I will say that your examples are nonsensical. What wing offers 250 lbs of downforce at 120 MPH with a drag penalty of only 12 lbs? At what AoA? I really would like to have a wing profile with that kind of ratio. If all wings were as equal as you suggest, we would all be running the same wing and would be paying a lot less for them than we do now.
Porsche, and everyone else, does not come out with new wings almost every year because it makes no difference. On a PRC GT car like I am building, the fore/aft location of a wing makes a difference in handling at Infineon. So I don't agree that wings don't matter at slower speeds.
The bottom line is that not all wings perform the same within a few percent. So, if I can get a good idea as to what wing generates the downforce I want with the least amount of drag, then what is the problem? It gives me a place to start. Then, if I have time, I can then test the wing against other wings that my friends have to see what works better for me and my car.
Maybe the best wing will be worth 1/8 sec a lap. There is time in the little things. Find 7 other little things like that and you are going a second a lap faster.
You don't get any faster making the assumptions you are making....
Scott
I have seen that it is futile to argue with you.....
But I will say that your examples are nonsensical. What wing offers 250 lbs of downforce at 120 MPH with a drag penalty of only 12 lbs? At what AoA? I really would like to have a wing profile with that kind of ratio. If all wings were as equal as you suggest, we would all be running the same wing and would be paying a lot less for them than we do now.
Porsche, and everyone else, does not come out with new wings almost every year because it makes no difference. On a PRC GT car like I am building, the fore/aft location of a wing makes a difference in handling at Infineon. So I don't agree that wings don't matter at slower speeds.
The bottom line is that not all wings perform the same within a few percent. So, if I can get a good idea as to what wing generates the downforce I want with the least amount of drag, then what is the problem? It gives me a place to start. Then, if I have time, I can then test the wing against other wings that my friends have to see what works better for me and my car.
Maybe the best wing will be worth 1/8 sec a lap. There is time in the little things. Find 7 other little things like that and you are going a second a lap faster.
You don't get any faster making the assumptions you are making....
Scott
01-04-2011, 09:52 AM
#49
Lifetime Rennlist Member
Mark,
I have seen that it is futile to argue with you.....
But I will say that your examples are nonsensical. What wing offers 250 lbs of downforce at 120 MPH with a drag penalty of only 12 lbs? At what AoA? I really would like to have a wing profile with that kind of ratio. If all wings were as equal as you suggest, we would all be running the same wing and would be paying a lot less for them than we do now.
Porsche, and everyone else, does not come out with new wings almost every year because it makes no difference. On a PRC GT car like I am building, the fore/aft location of a wing makes a difference in handling at Infineon. So I don't agree that wings don't matter at slower speeds.
The bottom line is that not all wings perform the same within a few percent. So, if I can get a good idea as to what wing generates the downforce I want with the least amount of drag, then what is the problem? It gives me a place to start. Then, if I have time, I can then test the wing against other wings that my friends have to see what works better for me and my car.
Maybe the best wing will be worth 1/8 sec a lap. There is time in the little things. Find 7 other little things like that and you are going a second a lap faster.
You don't get any faster making the assumptions you are making....
Scott
I have seen that it is futile to argue with you.....
But I will say that your examples are nonsensical. What wing offers 250 lbs of downforce at 120 MPH with a drag penalty of only 12 lbs? At what AoA? I really would like to have a wing profile with that kind of ratio. If all wings were as equal as you suggest, we would all be running the same wing and would be paying a lot less for them than we do now.
Porsche, and everyone else, does not come out with new wings almost every year because it makes no difference. On a PRC GT car like I am building, the fore/aft location of a wing makes a difference in handling at Infineon. So I don't agree that wings don't matter at slower speeds.
The bottom line is that not all wings perform the same within a few percent. So, if I can get a good idea as to what wing generates the downforce I want with the least amount of drag, then what is the problem? It gives me a place to start. Then, if I have time, I can then test the wing against other wings that my friends have to see what works better for me and my car.
Maybe the best wing will be worth 1/8 sec a lap. There is time in the little things. Find 7 other little things like that and you are going a second a lap faster.
You don't get any faster making the assumptions you are making....
Scott
The biggest problem with choosing a wing based on someone's CFD data is that it is probably not modeled on your car - the airflow to the wing might be very different than their model. But if you (or anyone else)has the model for your car, then CFD can be a great help.
Not sure if these guys can help you as they work mainly with sports racers, but they are some of the best aero folks focused on amateur racing. Give them a call and see what they can do or suggest:
Dauntless
01-04-2011, 01:36 PM
#51
Three Wheelin'
Too funny... A few of us in PRC GT cars have similar curved/banana wings from Getty Design.
I know that blue and yellow car... it raced in the very first PRC race at Buttonwillow in April 2002. I got the pole for that very first race...
It has been so long that I cannot remember why or how or by whom those banana wings were conceived/developed. I seem to recall that they were referred to as Crawford wings... but I just cannot remember. Those days when 993 cars were raced in FIA an IMSA are a little murky in my memory. Maybe there is some story in a back isuse of Excellence or Pano.
Anyway, my suggestions to Scott have been to examine what the other guys are using as well as trying to collect some other perspectives. Scott is an ex-motorcycle racer that has never turned a wheel on a car on a track, but he knows that little things can add up, and is justifiably looking for every advantage he can get in his build.
To me, the best choices are those with hard data acquired by people with appropriate engineering experience. Failing that, the next best thing is to sort through experience shared by folks with similar cars and circumstances. At least one of the vendors mentioned in this thread sells a wing based on a documented profile, but uses his own anecdotal experiences to describe how great the product is. That, in my mind, is silly. Really silly. As a marketing professional I'd recommend getting all of that stuff off of that web site-- totally destroys credibility.
Anyway, I do not believe in this case there are measurable sustainable advantages (as I have mentioned to Scott many times). I think there is no spoon, like the little child told Neo in Matrix.
I know that blue and yellow car... it raced in the very first PRC race at Buttonwillow in April 2002. I got the pole for that very first race...
It has been so long that I cannot remember why or how or by whom those banana wings were conceived/developed. I seem to recall that they were referred to as Crawford wings... but I just cannot remember. Those days when 993 cars were raced in FIA an IMSA are a little murky in my memory. Maybe there is some story in a back isuse of Excellence or Pano.
Anyway, my suggestions to Scott have been to examine what the other guys are using as well as trying to collect some other perspectives. Scott is an ex-motorcycle racer that has never turned a wheel on a car on a track, but he knows that little things can add up, and is justifiably looking for every advantage he can get in his build.
To me, the best choices are those with hard data acquired by people with appropriate engineering experience. Failing that, the next best thing is to sort through experience shared by folks with similar cars and circumstances. At least one of the vendors mentioned in this thread sells a wing based on a documented profile, but uses his own anecdotal experiences to describe how great the product is. That, in my mind, is silly. Really silly. As a marketing professional I'd recommend getting all of that stuff off of that web site-- totally destroys credibility.
Anyway, I do not believe in this case there are measurable sustainable advantages (as I have mentioned to Scott many times). I think there is no spoon, like the little child told Neo in Matrix.
01-04-2011, 01:44 PM
#52
Three Wheelin'
And by the way, Scott, you can visit with Kevin Mitz over in Campbell the if we go visit at Jerry Woods Enterprises next week. He is right around the corner. He is involved with Dauntless. His shop is next door to Rennwerks. He knows his stuff...
The world is small... Kevin was connected to Rennwerks (3rd overall at Daytona a few years back), and knows Tommy up at the Lizards... and so on.
The world is small... Kevin was connected to Rennwerks (3rd overall at Daytona a few years back), and knows Tommy up at the Lizards... and so on.
01-04-2011, 01:50 PM
#53
Rennlist Member
Reality is tought to swollow sometimes, but you make a good point. It is subjective to a point and the point is, that every little bit counts. (but even that is subjective and conditional too) . What I mean by that, is that some tracks you will have very little gains, and other a lot. some are essential. (remember that guy that lost his wing and ended up crashing his car) .
I never said, all wings are equal, i said there are subtle differences.
Now, you dont want to argue, but then you make a statement that shows you dont understand Drag to lift (L/D) ratios. you ask, and I provide. I provided a shape , a NACA numbered wiing that does provide the L/D that I disucssed, and if you read the diagram, and the post, that it included the AOA (angle of attack) Not many folks like to argue, especially, if they dont read what the argument is about.
https://rennlist.com/forums/8174532-post36.html
So , to answer your question, yes, there are many wings that provide 10:1 L/D at 15 degrees AOA. Now, we have already seen that the AOA is dependant on flow off the roofline, and that is an area that differs from each car. so, each wing design will work on each car at diffeent AOAs , differently.
Gains can be measured, effects will be positive and some negative depending on its influence on the system. What I mean by that, a higher downforce wing, might introduce more rear grip, and then introduce more UNDERsteer. I chased my tail with that for a few weekends until I started to understand splitters and air flow routing through the hood better. The point is, because of the leverage of the device at the rear of the car, even drag, produces additional downforce as well!
so, yes, wings are certainly effective. better wings give better drag figures and might work better during different applications and attitudes. we are talking through the turns, under braking, etc. yes, every little bit helps and THIS is why porsche and other companies come up with small changes to their components every year. It all adds up .
As far as testing wings and measuring effectiveness, thats a tough one, especially at a relitively slow track like Sears. Ive done it and there are lots of factors and trade offs. since we cant change wing settings on the fly, the trade offs you deal with and drive around, right?
A lot of the time, wings and even quality of tires sometimes, can be something that might not show in absolute lap time, but in how the car feels. this also goes with set up and many other facets of racing. if this wasnt true, the same car wouldnt have infinite setups for other drivers other than you.
Go ahead, experiment away. its all part of the fun. But dont kill yourself or your wallet for finding 1 second of lap time by using a "different" more efficient wing, because it probably wont happen.
I never said, all wings are equal, i said there are subtle differences.
Now, you dont want to argue, but then you make a statement that shows you dont understand Drag to lift (L/D) ratios. you ask, and I provide. I provided a shape , a NACA numbered wiing that does provide the L/D that I disucssed, and if you read the diagram, and the post, that it included the AOA (angle of attack) Not many folks like to argue, especially, if they dont read what the argument is about.
https://rennlist.com/forums/8174532-post36.html
So , to answer your question, yes, there are many wings that provide 10:1 L/D at 15 degrees AOA. Now, we have already seen that the AOA is dependant on flow off the roofline, and that is an area that differs from each car. so, each wing design will work on each car at diffeent AOAs , differently.
Gains can be measured, effects will be positive and some negative depending on its influence on the system. What I mean by that, a higher downforce wing, might introduce more rear grip, and then introduce more UNDERsteer. I chased my tail with that for a few weekends until I started to understand splitters and air flow routing through the hood better. The point is, because of the leverage of the device at the rear of the car, even drag, produces additional downforce as well!
so, yes, wings are certainly effective. better wings give better drag figures and might work better during different applications and attitudes. we are talking through the turns, under braking, etc. yes, every little bit helps and THIS is why porsche and other companies come up with small changes to their components every year. It all adds up .
As far as testing wings and measuring effectiveness, thats a tough one, especially at a relitively slow track like Sears. Ive done it and there are lots of factors and trade offs. since we cant change wing settings on the fly, the trade offs you deal with and drive around, right?
A lot of the time, wings and even quality of tires sometimes, can be something that might not show in absolute lap time, but in how the car feels. this also goes with set up and many other facets of racing. if this wasnt true, the same car wouldnt have infinite setups for other drivers other than you.
Go ahead, experiment away. its all part of the fun. But dont kill yourself or your wallet for finding 1 second of lap time by using a "different" more efficient wing, because it probably wont happen.
Mark,
I have seen that it is futile to argue with you.....
But I will say that your examples are nonsensical. What wing offers 250 lbs of downforce at 120 MPH with a drag penalty of only 12 lbs? At what AoA? I really would like to have a wing profile with that kind of ratio. If all wings were as equal as you suggest, we would all be running the same wing and would be paying a lot less for them than we do now.
Porsche, and everyone else, does not come out with new wings almost every year because it makes no difference. On a PRC GT car like I am building, the fore/aft location of a wing makes a difference in handling at Infineon. So I don't agree that wings don't matter at slower speeds.
The bottom line is that not all wings perform the same within a few percent. So, if I can get a good idea as to what wing generates the downforce I want with the least amount of drag, then what is the problem? It gives me a place to start. Then, if I have time, I can then test the wing against other wings that my friends have to see what works better for me and my car.
Maybe the best wing will be worth 1/8 sec a lap. There is time in the little things. Find 7 other little things like that and you are going a second a lap faster.
You don't get any faster making the assumptions you are making....
Scott
I have seen that it is futile to argue with you.....
But I will say that your examples are nonsensical. What wing offers 250 lbs of downforce at 120 MPH with a drag penalty of only 12 lbs? At what AoA? I really would like to have a wing profile with that kind of ratio. If all wings were as equal as you suggest, we would all be running the same wing and would be paying a lot less for them than we do now.
Porsche, and everyone else, does not come out with new wings almost every year because it makes no difference. On a PRC GT car like I am building, the fore/aft location of a wing makes a difference in handling at Infineon. So I don't agree that wings don't matter at slower speeds.
The bottom line is that not all wings perform the same within a few percent. So, if I can get a good idea as to what wing generates the downforce I want with the least amount of drag, then what is the problem? It gives me a place to start. Then, if I have time, I can then test the wing against other wings that my friends have to see what works better for me and my car.
Maybe the best wing will be worth 1/8 sec a lap. There is time in the little things. Find 7 other little things like that and you are going a second a lap faster.
You don't get any faster making the assumptions you are making....
Scott
Last edited by mark kibort; 01-04-2011 at 03:23 PM.
01-04-2011, 02:02 PM
#54
Rennlist Member
dont worry about the jab, i get it.
anyway, Not really. I dont think I am contradicting myself. We need the wings. can we drive around their effects or drive around not having one? sometimes. (slow tracks only). So, yes, i did a stock set up with my car before I finished the build and actually raced it at a track I know well. (a reasonably fast track too, as in Thunderhill) I mentioned the times were off, but not as far as I thougth they would be. much more of a handful was the car without aero. withe aero, coming back not changing anything but adding the aero wing and splitter (along with better tires) you could tell the effects, and it added much confidence in the fast turning spots.
Wings do work, but the differences in wings is more of a drag value which in itself is a small factor in the overall equation.
So, of course we need wings. I change settings occasionally based on feel and track and I think i can feel the difference. 2degree changes in rear wing settings, etc. I also have done testing between a kick tail stock spoiler wing that i modified and a real cup car wing. my testing has shown that with much less AOA, i can get much more downforce. of course with the cup car wing , i can get much more downforce period that is now used in my current set up.
One test was 250lbs at 7 dgrees AOA from horizontal at 120mph, but it might be more like an effective 15 degrees based on simulations of my car of the roofline effect of flow direction.
anyway, Not really. I dont think I am contradicting myself. We need the wings. can we drive around their effects or drive around not having one? sometimes. (slow tracks only). So, yes, i did a stock set up with my car before I finished the build and actually raced it at a track I know well. (a reasonably fast track too, as in Thunderhill) I mentioned the times were off, but not as far as I thougth they would be. much more of a handful was the car without aero. withe aero, coming back not changing anything but adding the aero wing and splitter (along with better tires) you could tell the effects, and it added much confidence in the fast turning spots.
Wings do work, but the differences in wings is more of a drag value which in itself is a small factor in the overall equation.
So, of course we need wings. I change settings occasionally based on feel and track and I think i can feel the difference. 2degree changes in rear wing settings, etc. I also have done testing between a kick tail stock spoiler wing that i modified and a real cup car wing. my testing has shown that with much less AOA, i can get much more downforce. of course with the cup car wing , i can get much more downforce period that is now used in my current set up.
One test was 250lbs at 7 dgrees AOA from horizontal at 120mph, but it might be more like an effective 15 degrees based on simulations of my car of the roofline effect of flow direction.
Just a gentle jab in the ribs Mark.
However I think you're sort of contradicting yourself to a degree in which you state certain absolutes and then pretty much say it's subjective and in the end not really substantial either way. Perhaps we're all kidding ourselves that at our speeds we need wings. Maybe it's all psychosomatic...but are you prepared to go back to a stock setup? Me either.
However I think you're sort of contradicting yourself to a degree in which you state certain absolutes and then pretty much say it's subjective and in the end not really substantial either way. Perhaps we're all kidding ourselves that at our speeds we need wings. Maybe it's all psychosomatic...but are you prepared to go back to a stock setup? Me either.
01-04-2011, 02:41 PM
#55
Race Car
Thread Starter
So I am not going to argue with you and I would appreciate it if you would not sully this thread anymore....
Scott
01-04-2011, 02:51 PM
#56
Mr. Excitement
Rennlist Member
Rennlist Member
Reality is tought to swollow sometimes, but you make a good point. It is subjective to a point and the point is, that every little bit counts. (but even that is subjective and conditional too) . What I mean by that, is that some tracks you will have very little gains, and other a lot. some are essential. (remember that guy that lost his wing and ended up crashing his car) .
I never said, all wings are equal, i said there are subtle differences.
Now, you dont want to argue, but then you make a statement that shows you dont understand Drag to lift (L/D) ratios. you ask, and I provide. I provided a shape , a NACA numbered wiing that does provide the L/D that I disucssed, and if you read the diagram, and the post, that it included the AOA (angle of attack) Not many folks like to argue, especially, if they dont read what the argument is about.
https://rennlist.com/forums/8174532-post36.html
So , to answer your question, yes, there are many wings that provide 10:1 L/D at 15 degrees AOA. Now, we have already seen that the AOA is dependant on flow off the roofline, and that is an area that differs from each car. so, each wing design will work on each car at diffeent AOAs , differently.
Gains can be measured, effects will be positive and some negative depending on its influence on the system. What I mean by that, a higher downforce wing, might introduce more rear grip, and then introduce more oversteer. I chased my tail with that for a few weekends until I started to understand splitters and air flow routing through the hood better. The point is, because of the leverage of the device at the rear of the car, even drag, produces additional downforce as well!
so, yes, wings are certainly effective. better wings give better drag figures and might work better during different applications and attitudes. we are talking through the turns, under braking, etc. yes, every little bit helps and THIS is why porsche and other companies come up with small changes to their components every year. It all adds up .
As far as testing wings and measuring effectiveness, thats a tough one, especially at a relitively slow track like Sears. Ive done it and there are lots of factors and trade offs. since we cant change wing settings on the fly, the trade offs you deal with and drive around, right?
A lot of the time, wings and even quality of tires sometimes, can be something that might not show in absolute lap time, but in how the car feels. this also goes with set up and many other facets of racing. if this wasnt true, the same car wouldnt have infinite setups for other drivers other than you.
Go ahead, experiment away. its all part of the fun. But dont kill yourself or your wallet for finding 1 second of lap time by using a "different" more efficient wing, because it probably wont happen.
I never said, all wings are equal, i said there are subtle differences.
Now, you dont want to argue, but then you make a statement that shows you dont understand Drag to lift (L/D) ratios. you ask, and I provide. I provided a shape , a NACA numbered wiing that does provide the L/D that I disucssed, and if you read the diagram, and the post, that it included the AOA (angle of attack) Not many folks like to argue, especially, if they dont read what the argument is about.
https://rennlist.com/forums/8174532-post36.html
So , to answer your question, yes, there are many wings that provide 10:1 L/D at 15 degrees AOA. Now, we have already seen that the AOA is dependant on flow off the roofline, and that is an area that differs from each car. so, each wing design will work on each car at diffeent AOAs , differently.
Gains can be measured, effects will be positive and some negative depending on its influence on the system. What I mean by that, a higher downforce wing, might introduce more rear grip, and then introduce more oversteer. I chased my tail with that for a few weekends until I started to understand splitters and air flow routing through the hood better. The point is, because of the leverage of the device at the rear of the car, even drag, produces additional downforce as well!
so, yes, wings are certainly effective. better wings give better drag figures and might work better during different applications and attitudes. we are talking through the turns, under braking, etc. yes, every little bit helps and THIS is why porsche and other companies come up with small changes to their components every year. It all adds up .
As far as testing wings and measuring effectiveness, thats a tough one, especially at a relitively slow track like Sears. Ive done it and there are lots of factors and trade offs. since we cant change wing settings on the fly, the trade offs you deal with and drive around, right?
A lot of the time, wings and even quality of tires sometimes, can be something that might not show in absolute lap time, but in how the car feels. this also goes with set up and many other facets of racing. if this wasnt true, the same car wouldnt have infinite setups for other drivers other than you.
Go ahead, experiment away. its all part of the fun. But dont kill yourself or your wallet for finding 1 second of lap time by using a "different" more efficient wing, because it probably wont happen.
Cranking a wing into angles where the air breaks away will greatly reduce its value. Tufts are one way to check. dots of thick white pigmented fluid is another. They will leave clean lines until the air flow becomes unstable.
01-04-2011, 03:10 PM
#57
Rennlist Member
sorry, i meant to say, "understeer". It was a real bad push. I posted the video back in 05.
now, Kurt, I also said, " a different wing" not no wing at all for finding a second a lap. You can get the same downforce with most any wing (being very general here)
now, Kurt, I also said, " a different wing" not no wing at all for finding a second a lap. You can get the same downforce with most any wing (being very general here)
I can't guess why you were having problems from increased downforce oversteer. As to a wing not giving a second. I am no expurt but I can twell you first hand a wing can make up a second and far more one way or the other. Taks the compound AoA wing and put it on a clean air car such as a 911 with a high mount wing. (I have seen just this setup too) Which area of the wing do you tune for? Which section will be under or over the sweet spot for AoA? a 4 or 5 deg change in the wing on the <white car to the left changes it from one car to altogether another at tracks such as VIR.
Cranking a wing into angles where the air breaks away will greatly reduce its value. Tufts are one way to check. dots of thick white pigmented fluid is another. They will leave clean lines until the air flow becomes unstable.
Cranking a wing into angles where the air breaks away will greatly reduce its value. Tufts are one way to check. dots of thick white pigmented fluid is another. They will leave clean lines until the air flow becomes unstable.
01-04-2011, 03:17 PM
#58
Rennlist Member
Scott, Im not arguing with you. What are you talking about "20.83:1" downforce to drag ratio??
I thought I showed you a 10:1 L/D ratioi wing and curves that would be very similar to the old Cup car wings. what am I missing here? Maybe Im reading the graphs wrong.
Let me (us) know.
Mark
I thought I showed you a 10:1 L/D ratioi wing and curves that would be very similar to the old Cup car wings. what am I missing here? Maybe Im reading the graphs wrong.
Let me (us) know.
Mark
Here's why it is futile arguing with you: You use a 20.83:1 downforce to drag ratio example and then tell me there are plenty of wings that provide 10:1. Then you tell me I don't understand the ratios.
So I am not going to argue with you and I would appreciate it if you would not sully this thread anymore....
Scott
So I am not going to argue with you and I would appreciate it if you would not sully this thread anymore....
Scott
01-04-2011, 04:16 PM
#60
Rennlist Member
Hey, Im sorry. I was just doing a quick calculation for drag by taking 1/10th the value, and used the MPH number (120mph) not the downforce. (thats where the 12lbs of drag came from) Sorry for the confusion. 250lbs of downforce would then be 25lbs of drag at 120mph in that case.
Now, my wing setting was at 7 degrees, but thats from horizontal. if you use the 7 degree number, the ratio goes up, but that is not reality. The point is, whether it be 10:1 or 15:1, its all in the 16 to 25lb range of drag. this is a pretty extreme range for different wings, and the net effect, is in the 1hp range for the differences between the two. (i.e. if the drag difference is 10lbs for example). Now, will 1hp effect your lap time, given that the downforce would be the same? this is the point of the discussion. The real difference might be on the wings effectiveness in grabing air in different attitudes and at slower speeds and that is where the art and science of this topic, come in to play.
Now, my wing setting was at 7 degrees, but thats from horizontal. if you use the 7 degree number, the ratio goes up, but that is not reality. The point is, whether it be 10:1 or 15:1, its all in the 16 to 25lb range of drag. this is a pretty extreme range for different wings, and the net effect, is in the 1hp range for the differences between the two. (i.e. if the drag difference is 10lbs for example). Now, will 1hp effect your lap time, given that the downforce would be the same? this is the point of the discussion. The real difference might be on the wings effectiveness in grabing air in different attitudes and at slower speeds and that is where the art and science of this topic, come in to play.