Most Effective Wing?
12-29-2010, 01:19 PM
#16
Race Car
Thread Starter
I would skip the CFD data and see if anyone has actual track data. CFD is useless if it was not done properly, and unfortunately its tough to find someone who actually knows what they are doing. Plus the conditions the CFD was done under are probably not what your car will be experiencing.
Good luck finding anyone with actual track data that is useful. Who would test multiple wings and share their results? Was their methodology reasonable? Is their car similar to mine?
CFD data gives me a reasonable place to start. The wing on my car is up in clean air. If I know what wing angles of a particular wing work well for my car, I can use that information along with the CFD data to determine what wing should give me the downforce I need with the least amount of drag. At least from a theoretical perspective.
Most people buy the wing "du jour" and assume it is the best for their application. And it may be. I want to dig a little deeper....
Scott
12-29-2010, 07:25 PM
#17
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Jeff, there are a couple of wind tunnels in NC, run by the same company. One is a rolling road, used by all the big money people, and its BIG BIG BIG BIG money.
The second is a stationary tunnel and is not all that prohibitively expensive. In fact myself and another are waiting for 2-3 more guys to join us. We can get half day - 6 hours for around 3 grand if I remember correctly. And from what I've been told, that's plenty enough time to test what we need.
The second is a stationary tunnel and is not all that prohibitively expensive. In fact myself and another are waiting for 2-3 more guys to join us. We can get half day - 6 hours for around 3 grand if I remember correctly. And from what I've been told, that's plenty enough time to test what we need.
Thanks,
Jeff
12-30-2010, 02:10 AM
#18
best wing
A friend and I had a wing produced in cf that is the same as what is run on the factory rsr .
I'll post pictures .
If you look at them they are flatter in the middle and go down on each side .
I don't know about the calculations but the engineer for Alex Job bought 2 for some prototype mazdas .
I'll post pictures .
If you look at them they are flatter in the middle and go down on each side .
I don't know about the calculations but the engineer for Alex Job bought 2 for some prototype mazdas .
12-31-2010, 03:01 AM
#20
Race Car
Thread Starter
97C2s911,
Your wing looks a bit like this wing:
http://www.aprperformance.com/index....ask=view&id=35
Did you guys do any CFD analysis for your wing?
Scott
Your wing looks a bit like this wing:
http://www.aprperformance.com/index....ask=view&id=35
Did you guys do any CFD analysis for your wing?
Scott
12-31-2010, 12:37 PM
#22
Instructor
Although not on my P-car, I recently had Titan Motorsports install an Aeromotions R2 Dynamic Wing for me. It has a 65 inch Carbon Fiber wing blade and aircraft aluminum uprights with 14 degrees of wing angle adjustment. The total weight of the wing, uprights and actuator control module with servos is about ~17 lbs!
Titan has a 996 Turbo track car that they may install one of these wings on. I was really fortunate that Greg Mark, one of the Co-Founders of Aeromotions was going to PRI in Orlando and asked if my car was at Titan (which is in Orlando as well) and came by to tune the wing for max down force. While he was there he discussed the plug-and-play tunes for the 996 and a few other Porsche models and the uprights that mount in the factory location.
For anyone not familiar with Aeromotions’ wings, here is a video of how it works on my Supra and how the max down force was determined:
They have both a dynamic as well as a static version of the wing. The first test I did with it in just static mode was a huge improvement in rear grip. I will be testing again at the Crown Region PCA DE at RRR later in January and cannot wait…
.
Titan has a 996 Turbo track car that they may install one of these wings on. I was really fortunate that Greg Mark, one of the Co-Founders of Aeromotions was going to PRI in Orlando and asked if my car was at Titan (which is in Orlando as well) and came by to tune the wing for max down force. While he was there he discussed the plug-and-play tunes for the 996 and a few other Porsche models and the uprights that mount in the factory location.
For anyone not familiar with Aeromotions’ wings, here is a video of how it works on my Supra and how the max down force was determined:
They have both a dynamic as well as a static version of the wing. The first test I did with it in just static mode was a huge improvement in rear grip. I will be testing again at the Crown Region PCA DE at RRR later in January and cannot wait…
.
12-31-2010, 04:09 PM
#25
Three Wheelin'
That Aeromotions concept is intriguing... from the video it seems that tuft testing with video is how they "characterized" performance on the particular car. Still, it is hard to quantify/compare the net benefit compared to a simpler and less expensive wing element.
I should think it pretty easy to get access to GT3 RSR wing elements... we have some local network connections to accomplish that, but I wonder again what the benefits would be on a different car and in different circumstances. Porsche AG and their various outside suppliers and consultants design the race cars as systems... and to adhere to various series rules. So all in all, hard to say again what the benefits would be on a 993-bodied car...
The replica RSR wings discussed/described here may have a connection to Gamroth, or some of his old contacts at Job... and he told the OP here to use the Predator... go figure. Seems like some clever stuff goes on up in the Pacific NW... I like some of the ideas in that blue car, especially the intake and intake air feed concept taken from the factory cars... I wonder what performance gains are there from colder and/or higher pressure air into the cf intake, and what weight gains come from the tail/wing set up, and what aero gains come as well... if any.
Of course the KMR/Crawford-Crawford 993 bodywork on the Brule car back in the day has a somewhat similar tail base design... with elements from the water-cooled world (that car was in Excellence some time ago... had a water-cooled engine... I got to see it and race against it in person at Laguna back in the day).
Everything here still looks like a guess. I think the answer is still that there is no spoon.
I should think it pretty easy to get access to GT3 RSR wing elements... we have some local network connections to accomplish that, but I wonder again what the benefits would be on a different car and in different circumstances. Porsche AG and their various outside suppliers and consultants design the race cars as systems... and to adhere to various series rules. So all in all, hard to say again what the benefits would be on a 993-bodied car...
The replica RSR wings discussed/described here may have a connection to Gamroth, or some of his old contacts at Job... and he told the OP here to use the Predator... go figure. Seems like some clever stuff goes on up in the Pacific NW... I like some of the ideas in that blue car, especially the intake and intake air feed concept taken from the factory cars... I wonder what performance gains are there from colder and/or higher pressure air into the cf intake, and what weight gains come from the tail/wing set up, and what aero gains come as well... if any.
Of course the KMR/Crawford-Crawford 993 bodywork on the Brule car back in the day has a somewhat similar tail base design... with elements from the water-cooled world (that car was in Excellence some time ago... had a water-cooled engine... I got to see it and race against it in person at Laguna back in the day).
Everything here still looks like a guess. I think the answer is still that there is no spoon.
12-31-2010, 05:06 PM
#26
Race Car
A few things.
If the rules allow it, you should go with significantly larger end caps than most of these pictures show -- especially down below the wing. (Check out Simon McBeath's aero book for good data on that.)
I think the active wings are a waste of time. Drag isn't that big an issue for racing. It's important for fuel consumption with aircraft.
You can easily test your front and rear aero if you've got a data logging system on the car. I bought two $5 ride height sensors from a junked Lincoln Continental air-ride setup and attached them to my front and rear suspension. I found an empty stretch of freeway and repeated 5-second stretches at 100 mph in each direction over the same stretch of road for a snapshot of data. There were clear differences in ride height from simply adjusting the angle of the wing. I learned that (with the wing I was running) it was easy to get too much downforce in the rear -- lifting the front up in a cantilever effect. This is with a vertical front air dam and 5" of splitter extending out in front.
It's also pretty simple to attache wool tufts (remember those rug-hooking kits from the eighties) and use a camera to observe adhesion and separation at different wing angles and speed. You look goofy doing it, but that's the price you've gotta play.
The position of the wing relative to the back of the car is important. In the case of my wing, four inches higher or lower (and four inches fore or aft) all produced significant drop-offs in performance.
I made my own wing out of Aluminum flashing material (for roofs) and 3M structural adhesives. It weighs less than four pounds, was static tested with 350 pounds of sand and hasn't fluttered into oblivion yet.
Most people set the angle of their wing relative to horizontal, which is a mistake. The airflow off the back of a 911 is about 12 degrees (I tested with wool tufts), so a 'flat' wing is already at 12 degrees.
The smartest way to go is to probably copy the factory efforts. They have more R and D money than any of us. The exception is stuff that's rule-specific. Vehicle height (and width) rules are one of the reasons the endcaps you see at races are so small. If the rules allowed it, those endcaps would be much bigger, and possibly at angles, like airplane winglets.
If the rules allow it, you should go with significantly larger end caps than most of these pictures show -- especially down below the wing. (Check out Simon McBeath's aero book for good data on that.)
I think the active wings are a waste of time. Drag isn't that big an issue for racing. It's important for fuel consumption with aircraft.
You can easily test your front and rear aero if you've got a data logging system on the car. I bought two $5 ride height sensors from a junked Lincoln Continental air-ride setup and attached them to my front and rear suspension. I found an empty stretch of freeway and repeated 5-second stretches at 100 mph in each direction over the same stretch of road for a snapshot of data. There were clear differences in ride height from simply adjusting the angle of the wing. I learned that (with the wing I was running) it was easy to get too much downforce in the rear -- lifting the front up in a cantilever effect. This is with a vertical front air dam and 5" of splitter extending out in front.
It's also pretty simple to attache wool tufts (remember those rug-hooking kits from the eighties) and use a camera to observe adhesion and separation at different wing angles and speed. You look goofy doing it, but that's the price you've gotta play.
The position of the wing relative to the back of the car is important. In the case of my wing, four inches higher or lower (and four inches fore or aft) all produced significant drop-offs in performance.
I made my own wing out of Aluminum flashing material (for roofs) and 3M structural adhesives. It weighs less than four pounds, was static tested with 350 pounds of sand and hasn't fluttered into oblivion yet.
Most people set the angle of their wing relative to horizontal, which is a mistake. The airflow off the back of a 911 is about 12 degrees (I tested with wool tufts), so a 'flat' wing is already at 12 degrees.
The smartest way to go is to probably copy the factory efforts. They have more R and D money than any of us. The exception is stuff that's rule-specific. Vehicle height (and width) rules are one of the reasons the endcaps you see at races are so small. If the rules allowed it, those endcaps would be much bigger, and possibly at angles, like airplane winglets.
12-31-2010, 05:06 PM
#27
Rennlist
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Aero is one of those things that unless you do a lot of testing in some fashion (and some people here have some very clever methods of testing - Jack) you really don't know where you are. I have seen a lot of well intended wings, but wonder at how effective they are. Lots of monkey see, monkey do going on.
For those of us without the resources, I think that a straight wing with a good aero design will ultimately prove the best overall. That said, I think that the flat center section on the wing that 97C2s911 has is probably to compensate for the different trajectory of the air coming off of the roof versus what is coming around the sides of the car. Since the air over the car flows somewhat downwards, you would want less wing angle there, and more out to the sides of the car in order to have more even angle of attack across the entire wing. I would speculate that it's design was probably the result of car-specific testing.
For those of us without the resources, I think that a straight wing with a good aero design will ultimately prove the best overall. That said, I think that the flat center section on the wing that 97C2s911 has is probably to compensate for the different trajectory of the air coming off of the roof versus what is coming around the sides of the car. Since the air over the car flows somewhat downwards, you would want less wing angle there, and more out to the sides of the car in order to have more even angle of attack across the entire wing. I would speculate that it's design was probably the result of car-specific testing.
__________________
Larry Herman
2016 Ford Transit Connect Titanium LWB
2018 Tesla Model 3 - Electricity can be fun!
Retired Club Racer & National PCA Instructor
Past Flames:
1994 RS America Club Racer
2004 GT3 Track Car
1984 911 Carrera Club Racer
1974 914/4 2.0 Track Car
CLICK HERE to see some of my ancient racing videos.
Larry Herman
2016 Ford Transit Connect Titanium LWB
2018 Tesla Model 3 - Electricity can be fun!
Retired Club Racer & National PCA Instructor
Past Flames:
1994 RS America Club Racer
2004 GT3 Track Car
1984 911 Carrera Club Racer
1974 914/4 2.0 Track Car
CLICK HERE to see some of my ancient racing videos.
12-31-2010, 05:07 PM
#28
Nordschleife Master
I've installed the GT Predator on the new car and do not have much testing on it as yet. In looking at the wing pics above, I notice that some are running Gurney flaps, some are not. Has anyone installed one on a Predator and if so, were you able to run less wing angle and still achieve the same downforce?
12-31-2010, 05:13 PM
#29
Rennlist Member
Jeff, there are a couple of wind tunnels in NC, run by the same company. One is a rolling road, used by all the big money people, and its BIG BIG BIG BIG money.
The second is a stationary tunnel and is not all that prohibitively expensive. In fact myself and another are waiting for 2-3 more guys to join us. We can get half day - 6 hours for around 3 grand if I remember correctly. And from what I've been told, that's plenty enough time to test what we need.
The second is a stationary tunnel and is not all that prohibitively expensive. In fact myself and another are waiting for 2-3 more guys to join us. We can get half day - 6 hours for around 3 grand if I remember correctly. And from what I've been told, that's plenty enough time to test what we need.
Professional Racing and Driving Coach
Last edited by Veloce Raptor; 04-27-2011 at 08:46 PM.
01-01-2011, 01:11 AM
#30
But, curious how you determined the angle of the airflow where it meets the leading edge of the wing.
I've tufted various wings at angles up to about 10 degs (from horizontal) and they always showed smooth airflow. If the angle of attack had been 22 degs, I would have expected to see some burbling. No?