The availability of inexpensive extruded aluminum wings has changed motorsports. Ten years ago it was rare to see a wing on a budget endurance racer or HPDE car. Now they are everywhere. A lot of the credit (blame?) goes to Johnny Cichowski of 9 Lives Racing, who sells an inexpensive extruded aluminum wing that sets the standard for the industry.
When you have a winning formula, people copy you. That’s the nature of business. That’s also the nature of racing. And so it’s no surprise that someone else has created a similar product.
This new extruded aluminum wing comes from Michael Jui of Wing Logic. He got wind that I was going to a wind tunnel, and asked if I would test his product. Of course I said yes, because I want that data, and I think the racing community as a whole would like that as well. So let’s take a look at this new wing in as much detail as I can, and compare it to the 9 Lives Racing Big Wang.
Wing Logic’s chord measures about 9.8”, while the 9LR wing is 9.2” across the top. So, the Big Wang is actually the smaller wing.
The wingspans are slightly different, as Wing Logic’s comes in standard lengths of 60″, 65”, 70″ and 72″. 9 Lives makes their wings to fit certain models, but you can also order a custom length. This is important because most racing rules limit wings to body width, and so if you have a Miata, you need to trim an inch off the 65″ Wing Logic, and re-tap the holes on one side. I didn’t do that for this test, so Wing Logic has a slight advantage, with 1″ more wingspan.
The construction of the wings are pretty similar, but Wing Logic has some extra internal thickness in a couple places, and while 9 Lives uses 5mm hardware for the end plates, Wing Logic uses 6mm. The Wing Logic end plates are 3mm, which is thicker than I’ve seen anywhere. All of this adds up to a wing that is sturdier, but heavier. A 65” Wing Logic fully set up with end plates and welded bottom mounts weighed 16.6 lbs. A 9 Lives 64” wing dressed the same weighed 14.6 lbs.
The shape of the wings are similar, but not the same. Anyone who says Wing Logic copied the 9 Lives Racing shape is simply wrong. As near as I can tell, Wing Logic is using a CH10 (Chuch Hollinger CH 10-48-13), which is a low Reynolds high-lift aviation airfoil, while the 9 Lives Racing wing was designed as a motorsports wing from the start.
If you measured Wing Logic in Benzing coordinates it’s a Be 133-105, while 9 Lives measures Be 123-125. That means the position of maximum thickness and maximum camber are the same in both wings, and that’s why they look similar. But Wing Logic’s is thicker and 9 Lives has more camber.
If you want to dive deep on that topic, I wrote an article on Car Wing Comparisons. Of all the wings I investigated, the most efficient was the CH10. But that is based on free stream efficiency, which means that the wing is not on a car, but just suspended in the air.
Cars are large and aerodynamically inefficient compared to wings, and when you put a wing on a car, the drag doesn’t go up that much, but the downforce does. So you usually get the best vehicle efficiency by choosing a wing that has the most downforce, not by choosing a wing for its efficiency or low drag.
Enough preamble, how do the wings compare in the wind tunnel?
Wind tunnel testing
I use the A2 wind tunnel, because for people like me, it’s the only game in town. I’ve tried to get into other wind tunnels, and either I’m not allowed, or it’s prohibitively expensive. The Aerodyne wind tunnel next door has a rolling floor, and I’d like to try it, even if it’s 4x the cost. But the rollers are designed for NASCAR, so unless I bring a car with a 109″ ish wheelbase (Miatas are 90″), I’m shit out of luck.
A2 doesn’t have a rolling floor, and so the effect of the tires rolling on the ground can’t be measured. This is significant for underbody testing, but you can measure things on the front of the car and over the body with acceptable accuracy.
There’s a lot of online conjecture by people who have never been to A2, that the small size of the wind tunnel, and the proximity of the walls, contributes highly to a blockage rate (or ratio?) that makes this wind tunnel results inaccurate. However, the walls in the tunnel are designed to reduce the blockage, by being curved rather than flat. And I’m also not after 100% accuracy, I’m looking for deltas – the difference between this or that. Did this wing have more or less drag than the previous wing? Did it produce more or less downforce? These things can be measured with accuracy at A2.
For the wind tunnel testing, I wanted to to use a car that already had CFD done on it, so I borrowed Phil Sproger’s car. His NA Miata has a 9 Lives Racing medium aero kit, and we set the ride height so that it would be as close as possible to the specifications that Morlind Engineering used when they ran CFD for 9 Lives Racing. (AJ Hartman and I did 42 runs on this car, baselining the car vs CFD, and then testing wings, spoilers, fastbacks, and many other ideas for drag and downforce. You’ll be able to read about that in a future report.)
We tested a 65″ Wing Logic back to back with a 64″ Nine Lives. Wing Logic has a built-in 1/4″ Gurney flap, and 9 Lives Racing has a slot for Gurney flaps of various heights, and we used a 1/2” Gurney. But because the slot is slightly recessed, this is more like 3/8”. So while one wing was slightly larger, the other had a slightly taller wicker, and it should be a fair fight.
I also threw in a strange DIY wing I made to see how it compares. It measures 41″x16″, and looks like an old-school F1 wing. The low-aspect ratio would not work in its favor, however the extra chord should make the wing slightly more efficient by having a higher Reynolds number.
Let’s see how they measured up at 100 mph, using the following fields:
- Front downforce – This is a negative number, which you can think of as lift. When you add rear downforce (or drag), it lifts the front of the car through leverage, like a see-saw.
- Rear downforce – This is the wing’s job, and varies with wing angle, Gurney flap height, and many other variables.
- Total downforce – Front lift and rear downforce combined.
- Drag – The number of pounds of drag the wing adds. This is a pretty meaningless number on its own, but is used to calculate the L/D ratio.
- HP – An easier way of thinking about drag is how much horsepower it consumes.
- L/D ratio – This is also known as aerodynamic efficiency, and is usually a good way of determining which part is better on the car. Note that the numbers in this table are not the bullshit free-stream efficiency you see in CFD, but the actual returned efficiency as run on the car.
As you can see from the data, at zero degrees angle of attack, Wing Logic, 9 Lives Racing, and my DIY wing are all better than a 10:1 L/D ratio. At this setting, the Big Wang makes the most downforce, and is thus the most efficient by about 5%.
When I set the wings to 5 degrees, Wing Logic and 9 Lives are identical in terms of aero efficiency. The Big Wang makes slightly more downforce, but the bigger wing makes less drag, and they are effectively the same at this setting. This is also about the maximum angle you can set, because air is coming down the roof at 5-7 degrees, and so if you use more angle than this, the center of the wing stalls, which adds drag and reduces downforce.
As a side note, my chunky DIY wing was similar to the other wings at zero degrees, by virtue of less drag. I should have tested it at the same 5 degrees as the others, because it was stalling at 7 degrees. It’s definitely the worst wing here, but not by a lot. On the plus side, it weighed on average 6 lbs less than the aluminum wings, and it cost me $30 in materials!
To get back to the actual contenders here, the two aluminum wings performed the same at 5 degrees AoA, but that isn’t the whole story, because the Big Wang is dimensionally the smallest. If you are racing in a class that limits total wing area (GLTC 500 square inch wings, for example), then the 9 Lives wing will give you about an 8% advantage over Wing Logic. It’s not a huge difference, but in a rule set that limits wing area , I’d take the Big Wang.
The full results of the wind tunnel testing are in my Miata Wind Tunnel Report, where I go into not only wings, but different tops, front end options (canards, hood and fender vents, splitter adornments, etc. You can purchase the report here by clicking the button, and you’ll get a link where you can download it.
| If you don’t want to invest in the wind tunnel report, but you want to support this kind of investigative content, Buy Me a Coffee. It takes 15 coffees ($5 each) to pay for one run in the wind tunnel. That doesn’t count the many hours of preparation, towing 11 hours each way, gas, hotel, and other expenses I accrue on the way. Your support makes it possible for me to do community-driven wind tunnel testing. Thanks! |
CFD vs wind tunnel
Both 9 Lives Racing and Wing Logic publish CFD results of their wings, and I thought it would be illuminating to see how accurate those are compared to the A2 wind tunnel. Wing Logic use Kyle Forster to do their CFD, and he used a 70” wing on a Mustang rather than a 65” wing on a Miata, so it’s not a direct comparison. Kyle used the same CFD settings as he did for AJ’s wings, which have generally landed within about 3% on loads in the same tunnel with matching cars/positions etc, so A2 correlation should be OK for this data.
Note that the reference area for the Miata is 1.67 meters squared (18 square feet), while in the CFD, it’s set at 1 meter squared. Ergo, I need to multiply the CFD numbers by 1.67 so that they match the wind tunnel data. When I do that, you can see, the wind tunnel returns similar downforce as the CFD, but drag is higher in the simulation.
Is this a big problem? Not really. After testing the same wing on a Veloster N, an 8th Gen Civic coupe, a Miata, and a Supra, I can tell you that the shape of the car has a greater impact on a wing’s performance than any CFD error. On a hatchback, I’ve seen a 3.5:1 L/D and on a coupe up to 24.5:1. In the end, the main difference between CFD and wind tunnel results isn’t computer vs real world, it’s the shape of the car. A Miata ain’t a Mustang, and that’s likely where most of the differences lie between the Wing Logic CFD and wind tunnel data.
9 Lives Racing also publishes CFD using a 64″ wing on a Miata, and that’s exactly what we brought to the tunnel. So we can get an apples to apples comparison on this wing for shiz. But 9 Lives doesn’t publish coefficients, they only give us drag and downforce. Still, it’s enough to work from.
Comparing the wind tunnel results to CFD, the computer predicted both less drag and less downforce than we got in the wind tunnel. The fact that the CFD was off by 33% in downforce points to some kind of problem with that model.
I base that on another nugget Kyle dropped on me which is that as a general rule of thumb, if CFD is off by <20% it could be correlation, <30% it’s setup differences, >30% something has gone wrong with the output numbers at some point or the CFD is extremely broken. So I’m not sure what’s going on with the 9 Lives / Morlind Engineering CFD, but it’s not matching real-world values very closely. When we tested the whole car (not just the wing), the drag was also off by a lot (as in .4 vs .6).
70″ Wing Logic, end plates, 3/4″ Gurney
I was also able to test a 70″ Wing Logic on my Hyundai Veloster N, which allowed me to compare the effect of wingspan on a hatchback. Last year I tested a 55″ Big Wang on my Veloster, and since Wing Logic and 9 Lives are pretty similar, I can get find out how much I was giving up with a shorter wingspan.
I also wanted to try 12″ square end plates to see if the smaller end plates were giving up some performance. And since Wing Logic has a built-in Gurney flap, I also wanted to see what would happen if I butted up a 3/4″ Gurney flap against that. (If you’re wondering what a 1/2″ Gurney would do, you can just average the numbers).
Comparing the 70″ Wing Logic to 55″ 9 Lives is absolutely not fair, so think of this only as a comparison of wingspan. The longer wing made 10 lbs less downforce (what in the actual fuck?), but had a lot less drag. The end result is a much better L/D ratio of 7.4:1 for the longer wing compared to about 3:1 for the shorter wing.
Now this is flatly absurd, because according to Kyle, an increase of 100mm span is worth about 7% load on the same car, so an increase in 15″ span (375 mm) should be an increase of 26% difference in load, not a decrease of almost 7%. I’m not sure what’s going on here, as the wing was in a similar position, and on the same car.
Changing the smaller end plates for 12″ square end plates added 7.2 lbs of downforce, but also used an additional 1.1 hp in drag. The change in parts returns a L/D ratio of 1.3:1, which means the smaller end plates would be faster anywhere but an autocross course.
Adding a 3/4″ Gurney flap added 48.1 lbs of downforce for 21.4 lbs of drag, which works out to a 2.25 L/D ratio. If you need more rear downforce, adding the larger wicker would be worthwhile on just about any track that isn’t a high speed oval.
Conclusions
Comparing the two wings, my main gripe is that Wing Logic’s wing is 2 pounds heavier than a 9 Lives wing of the same length. That’s not a lot of weight, but the location of the weight, high up and at the polar end of the car, isn’t helpful. As previously stated, in a racing class that limits the wing size to a certain amount of total area, 9 Lives has a slight advantage.
Those negatives aside, Wing Logic has a fine product that is well constructed and performs similarly to the Big Wang. At $349-399 with free shipping, Wing Logic’s wing is a downright bargain.
Occam's Racer 