I've been lurking around here for a while and I think I have something the community may be interested in.

A few months ago, I came across a company with one of the coolest aftermarket products I've ever seen. Their name is Aeromotions and they make active rear wings. I've been interested in aerodynamics for a while and their device struck a chord with me. To sum it up, they employ a three-axis accelerometer which actuates a highly efficient airfoil in order to provide the vehicle with downforce when needed and low-drag when downforce isn't wanted.

Jim Hall's Chaparral 2E, Gordon Murray's McLaren F1 and Bugatti's Veyron are some of the most notable cars equipped with an active wing. Clearly it's not a new concept, but Aeromotions has made the device affordable, completely transparent to the operator and easily retrofitted.

I contacted Aeromotions and commissioned a wing for my RS. They took the car for a while and returned it to me with a fully-functioning active wing package consisting of a replacement decklid which houses the motors, linkage and mounts for the airfoil, a new airfoil, a small processor in the cabin and a remote control for fine-tuning.

In my mind, the airfoil is one of the most interesting components of the system. It has a shorter chord (distance from the leading edge to the trailing edge) than the factory RS wing but it shares the top profile of the factory wing. The underside is where things get interesting. The shape is much different and incorporates a concave area to slow the air traveling underneath, resulting in more downforce. The wing's shape is used in Unmanned Aerial Vehicles (UAVs) such as the Predator drone. UAVs spend a lot of time at low speeds loitering over areas. Operating between 85-135 MPH necessitates a wing that is extremely efficient as it must produce a lot of lift to keep the craft airborne. Coincidentally, these speeds are similar to those of a car driving on a track.

The other deviation from the stock airfoil is the width. The factory RS wing is 57 inches wide. They tested a 57-inch unit as well as a 65-inch unit and found that the 65-inch blade indeed makes a difference. Four inches on either side doesn't seem like it would do much, however the air flowing over those four inches is less affected by the body of the car and thus cleaner. I also happen to like the look of the 65-inch wing, particularly on the wide-bodied cars.

The system has three modes and each mode has a defined Angle of Attack (AoA) for the airfoil:

• Straightaway: Lowest AoA to produce the least drag under forward acceleration
  
• Braking: Highest AoA to produce the most downforce possible before stalling the air moving over the wing
  
• Maneuvering: AoA between maximum downforce and low drag which helps keep the rear planted while cornering

On the road, the function of the wing was imperceptible until I made a high-speed run in the rain and got on the brakes. Prior to the active wing, the rear would wiggle slightly under hard braking and the problem was exacerbated in the wet. It was never dangerous, but it was a but unnerving.

After the addition of active aero and while braking hard in the wet from speed, the wing helped stabilize the rear tremendously. It literally felt like a different car.

Aeromotions crunched a lot of numbers and ran multiple CFD models before delivering the car to me. That's all well and good, but it's no substitute for track testing. A few weeks ago, I sent the car to VIR with a some good friends who happen to be great drivers. They're not pros, so their feedback was very important to me because I'm not a pro. Both guys have a lot of seat time in Porsches and they had nothing but praise for the wing.

While at the track, we got Craig Stanton behind the wheel for his feedback. If you're not familiar with Craig. He's won Koni Challenge and Grand-Am championships in Porsches, so he knows what he's doing, especially compared to my cadre of miscreants.

Craig was blown away by the aero package. On the first of two days, he was very fast with the wing, but he wanted some changes. He felt that the car could use more downforce in the corners than the maneuvering AoA provided, so he asked for some "minor changes."

To their credit, the Aeromotions guys pulled an all-nighter and rewrote the algorithm governing wing function. Their changes modified the system's behavior such that it maintains the braking AoA throughout the corner until the accelerometer sees lateral acceleration drop and vehicle speed increase, at which time the wing drops to straightaway mode.

Craig's results were validation of this entire endeavor. In back-to-back testing of the fixed wing versus active using a TraqMate, he picked up over 12 MPH on the front straight, over 8 MPH at the end of the uphill esses, over 7 MPH on the back straight and knocked off more than 1.6 seconds over a full lap. More than once he said that the wing saved him from spins. He was able to brake later as well as shorten the braking zones. He made two comments that stuck with me more than the others: "This thing's *****in' like a Camaro'" and "It's the greatest thing since the banana!" In Craig-speak, these are very positive comments.

I haven't gone through all the data yet, but I'm sure there's more to be gleaned from it. Two days of open-lapping produced more data than I have time to analyze.

After the car returned from VIR, I swapped the orange factory endplates with some flat polygonal plates made of carbon fiber. I haven't had time to clean the car and take my own photos, but I'll do so soon and show photos of the remote control and processor. Here's what I can offer:

An early CFD model:



Here's the prototype:





Test-fitting the decklid:



Finished product:



57-inch blade:



65-inch blade:



57-inch blade:



65-inch blade:







I have hours of track footage, however I haven't had time to edit the files to manageable sizes. Here's a short video of it working on the street:

http://www.youtube.com/watch?v=5vdb6S2hyAI

Nevertheless, I thought you guys might be interested in the device. I've tried to explain it as best I can. If you have any specific questions, I'll do my best to answer them. If I can't answer them, I'll find someone who can. The only question I won't address is price: I don't want there to be any confusion regarding my relationship with the company. Pricing implies sales and I didn't create this topic to sell wings or spam the forum.

Note to moderators: I have no affiliation with the company other than being the first to ante up and get the project done. I am not a salesman for the company, nor do I have any sort of arrangement whereby I get commission from Porsche sales. I'm simply a happy customer and enthusiastic about a company formed by two very bright kids with a novel product that actually works.

EDIT: One of my criteria when developing this product was that it require no permanent modifications to the vehicle. I want to keep the car as original as possible for whomever becomes the car's next custodian. That means I will not sell the factory wing. I appreciate the offers to buy it, however it will only be sold with the car attached to it.

 

Looks like a very well made piece.. I wont even ask the price.. Dont worry.. LOL

Mike

 

You certainly earned my respect for being interested and willing to try something so innovative. Developing that system was certainly not cheap.

I think it is cool as hell. And active aero is in-arguably effective. The soon to be sold McLaren MP4-12C street car uses similar technology to achieve the same goals of increasing traction and reducing aerodynamic drag.

Kudos to everyone involved with your project.

 

very, very cool -- thanks for sharing!

 

This looks absolutely awesome! Great job with development. Are you running the 65" full time?

 

Thank you for the sentiment, but I really didn't do anything but express interest and provide means to get the project done. My respect goes to the engineers. They spent a lot of man hours getting it right. The device went through several iterations before they were happy with its performance. Additionally, they were able to use the development as a learning tool by providing internships for engineering students who helped to accurize the CFD models by measuring every square centimeter of the car, including the underside. A lot of people benefitted from the project and everyone walked away happy.

Regarding the cost, I didn't mean to imply that it's astronomical and out of reach for most consumers. To the contrary, it's a bargain compared to replacing the factory decklid and wing and becomes downright cheap when looking at the track data. People spend unconscionable amounts of money to shave tenths and this device shaves seconds. Now that the data has been gathered and the 997's aero is understood, this can be fitted to all of the platform's variants.

 

Thanks. I think it looks killer, especially with the different endplates. I am running the 65-inch blade full time. The 57-inch is destined to be reborn as a shelf in my basement which will provide me space to display some model cars.

 

Pretty cool! You could probably cut down on wear and tear if you limit its use to higher speeds. I don’t think aerodynamics when pulling up to a stop sign are that crucial. At least I got too see a cool product before the mods undoubtedly step in and make a big deal about sponsorship bs.

 

very interesting!!! i went to their site and they don't show a fitment for the porsche yet but i could be interested in this as ballparking the wing angle through trial and error is not fun and the time to do so just cuts into my pleasure time.
i hope they set up a default street angle so as not to wear itself out on the street, then just hit a button to activate the system.
thank you for the share.

alan

 

I expressed concern over that and was assured that the actuators are good for millions of cycles, so I'm not worried about it wearing out. I know that I have the ability to turn it off (though I don't know precisely how), but I drive the car daily and it's nice to have the ability to dial up the downforce in the rain.

I don't see where an issue would arise. I'm neither sponsored nor an employee. I'm just a happy customer who purchased a product that works well. There are no competing products on the market, so vendors have no valid gripes. In fact, I would go so far as to say that a savvy vendor would not complain and reach out to the manufacturer and secure distribution rights for the device. It's a novel widget which underwent years of development for other applications and cannot easily be replicated without massive investments of capital and time.

Back to the airfoil for a moment. I forgot to add hard data regarding downforce:



The black graph shows the airfoil's coefficient of lift at a given AoA. You can see the peak which represents maximum AoA before stalling.

The table shows the amount of downforce at given speeds with maximum and minimum AoA. According to the August 2009 issue of 'Excellence', the new GT3 produces 154 pounds of rear downforce at 188 MPH. That's less than the wing on my car produces at 100 MPH. The relevant pages of the article can be seen here and here.

 

awesome looking moving tail. its functional as well as good looking. i also like the wider look

 

smindustries,

Looks great and I think that I would consider it for my car. With the additonal downforce in the rear what have you done to balance the downforce in the front?
Wouldn't the car get lighter in the front at high speed unless ther is assitional downforce in the front? How about a similar variable setup for the front?

 

Nice work, any pictures of the 65" blade on a NB GT3.

 

I've done nothing yet, but they're developing another device for me to balance out the front which is just as trick as the rear. My lips are sealed for now.

What I will say is that data modeling has demonstrated that a splitter with no vents, such as simply blocking off the vents with tape, produces ~10% more downforce. The Cup splitter produces a bit more because it's lower.

When one thinks of downforce as being static, that's a logical question. On a conventional setup, one must play with AoA to produce enough downforce for corners without sacrificing too much top end. Defining what works best has historically been a game of compromises.

Now that the rear wing is dynamic, it reduces downforce at high speeds. When the processor sees only forward acceleration and a vehicle speed in excess of 70 MPH, the wing drops to an AoA of 0º. Ergo, the wing is producing as little downforce as possible at speed. If you look at the above chart, you'll see that traveling 150 MPH at an AoA of 0º only produces 65 pounds of force.

The conventional wisdom of a car at speed getting light in the front when running lots of wing no longer applies.

No, sir. My car is the only one equipped with it at present. The photos are a little misleading insofar as the wing does not extend to the entire width of the car. It's about an inch inboard of the rear quarter panels, so it would likely be flush with the quarter panels of a narrow-bodied car.

If there's someone with a GT3 in the DC metro area who wants to swap trunks to get an idea of how it would look on a narrow-bodied car, I'm game.

 

Anyone know the width of the RSR wing? This looks to be almost as wide. I am currently using the cup splitter and this wing would likely balance things out better than the stock wing. Also, what exhaust do you have?