The wing is installed!

"InfinityAero" (infinityaero)
07/24/2017 at 20:35 • Filed to: None

Still need to make wing tips and bolt them on. Will likely cut the mounts about an inch shorter to get more adjustability out of the turnbuckles. No vibrations/flex up to 65mph. Will be pulling it all apart to add neoprene pads, paint the mount components, and repaint the wing. Rear hunkers down nicely at 45+!

I had to add the aluminum supports because my mounts were a little too flexy laterally... it was that or moar CF, and I was sick of doing layup work. I think the look works anyways... happy to have it (95%) done!

Here are the posts detailing the build:

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DISCUSSION (18)

Bman76 (hates WS6 hoods, is on his phone and has 4 burners now) > InfinityAero
07/24/2017 at 21:08

“Rear hunkers down nicely at 45+!”

(wing is entirely in turbulent flow from roof and is literally doing nothing but adding drag)

Not trying to hate on your work, but it’s not gonna do much for ya.

NYankee1927 > Bman76 (hates WS6 hoods, is on his phone and has 4 burners now)
07/24/2017 at 22:17

ehhh I bet if you put in the max angle of attack before stall and drive the car like 120 it might do something. You will never feel the rear hunker down though. I’m pretty sure the Mustang FR500S actually had some aero data published and it made ~100 lbs of downforce at 120 mph. Compare the size of that wing to this one.

Bman76 (hates WS6 hoods, is on his phone and has 4 burners now) > NYankee1927
07/24/2017 at 22:25

Or you could just but a 6-8" lexan spoiler on the rear a la Blackbird Fabworx Lexan Spoiler for Miatas.

Kinja'd!!!

NYankee1927 > Bman76 (hates WS6 hoods, is on his phone and has 4 burners now)
07/24/2017 at 22:29

Hey now we’re talkin!

Jayhawk Jake > InfinityAero
07/24/2017 at 22:35

That looks less than effective. Put some yarn tufts on it and see if they’re actually doing what they should.

It also just looks bad, but hey, your car

DutchieDC2R > InfinityAero
07/24/2017 at 23:03

Its your car and I respect that.......but jesus that wing ruined a nice S2000 butt....

Textured Soy Protein > InfinityAero
07/25/2017 at 00:44

Kinja'd!!!

InfinityAero > Bman76 (hates WS6 hoods, is on his phone and has 4 burners now)
07/25/2017 at 07:56

It’s actually taller than the CR wing, which has been wind tunnel tested to eliminate lift. Worked too well yesterday and sheared through one of the bolts on the turnbuckles that are rated for 50lbs of force. I think it’ll work just fine. Too well seems to be the current problem, and that was with 0 degree AOA in the middle.

I’ll be able too see from my mileage if it adds a ton of drag, and yah laminar flow is optimal, but I’m not going to mount it a whole foot higher, and neither did Honda with their wing.

InfinityAero > NYankee1927
07/25/2017 at 07:59

Mustang likely generating lift prior to the aero work. Many cars generate lift at speed. For CR, Honda didn’t advertise how much down force they created, but rather said 80% lift reduction... they never got to the point of creating downforce... that would be above and beyond the lift generated by vehicle. May be a factor...

InfinityAero > Bman76 (hates WS6 hoods, is on his phone and has 4 burners now)
07/25/2017 at 09:18

Also, I’ll be testing it at an AutoX practice day without the wing, with the wing at a neutral AOA in the middle, and at an agressive AOA on the tips (20 degrees). The speeds are low enough I won’t have to worry about damaging the trunk or car while experimenting and I should be able to see whether it’s having any impact. I wouldn’t expect much regardless... but it would demonstrate if it’s doing nothing but hurting performance.

NYankee1927 > InfinityAero
07/25/2017 at 09:24

Get shock pots and get us some data on yours. Fill in the holes! Also, yep almost all cars make lift. It makes it really impressive how they managed so much downforce with the ACR. A full flat bottom and diffuser goes a long way I guess.

InfinityAero > DutchieDC2R
07/25/2017 at 09:24

I think any appearance mods to the S2K make it look progressively worse, including the CF hood and lip kit mine had on it when I bought it— I’ll probably buy replacements for those before I buy a new trunk just because I put a couple holes in it. I also like to drive the car hard... so some aero is nice when I want it. This is more just fooling around with an engineering project.

InfinityAero > Jayhawk Jake
07/25/2017 at 09:32

Yarn tufts are definitely part of the plan, as is doing some AutoX runs with and without it. That’ll be a minimal impact, obviously, with the low speeds on an AutoX run, but it’ll give me an indication if it does nothing but harm.

I’ll probably drive around without it on most of the time (holes plugged) and just throw it on for AutoX and canyon runs with friends... I don’t need the downforce (or the drag) from a wing for my weekly commute, don’t mind the appearance with plugs in the trunk, and plan on keeping the car for a long time (or forever) so I’m not particularly concerned about resale value at the moment. Honestly, I think any appearance mods to the S2K make it look progressively worse, including the CF hood and lip kit mine had on it when I bought it— I’ll probably buy replacements for those before I buy a new trunk just because I put a couple holes in it. I also like to drive the car hard... so some aero is nice when I want it. The car has always had a sensation to me of the rear starting to lift at speeds, and the Aero studies I’ve seen done on the s2K and the Miata bear that out— a wing/spoiler and front lip are the common ways to address that lift.

This is more just fooling around with an engineering project... if I were going for looks I’d spend the $1,500 on the non-adjustable CR wing and trunk. This was about $200 of materials, most CF and sandpaper, and I get to adjust it to my heart’s content for functionality.

InfinityAero > NYankee1927
07/25/2017 at 10:19

Those shock pots look pretty cool. If I’m understanding how they’re used, that would give me an idea of the force being generated on the rear mount— the wing is hinged at the front of the mount so it wouldn’t account for the energy being transferred to the CF mount at that pivot point...

The down-force numbers on the ACR are incredible, for sure. Looking back at the evolution of the Viper, you can see how much of an influence aerodynamic studies and racing research had on the design of the car and just how much of an impact on the dynamics of the car that Dodge’s engineers were able to achieve.

From what I’ve heard that underbody tray is huge— to the point that it’s worthless to install a diffuser under the rear of most cars without having the tray leading up to it. Prius owners build underbody trays out of corrogated plastic sheeting, apparently, to add a few mpg, so they’re pretty effective at reducing drag as well.

Combining that with a lip really eliminates a lot of the air that’s able to sneak under the car and a lot of the lift force generated. You can take it a step farther by having a vented hood to allow air that does make it’s way under to flow upwards instead of under.

My basic plan is to have a removable canyon package I can throw on my car in short order... or drive without during my weekly commute. Front lip extender to get the lip lower than 3" off the ground (the minimum effective point, based on CFD studies of a Miata, front lip is 4" off ground currently), wing, underbody tray, rear diffuser. The underbody tray and rear diffuser I’d likely leave on all the time since you’d never see the tray and the diffuser should be inoffensive enough. Still a lot of research to do... but hopefully many many years of owning the car.

NYankee1927 > InfinityAero
07/25/2017 at 10:41

You would actually attach the shock potentiometer directly to your shocks. If you are generating downforce, going down a straight you will actually see the suspension compress as the aero load goes higher. Multiply that displacement by your spring rate and you get downforce.

Jayhawk Jake > InfinityAero
07/25/2017 at 12:27

I hadn’t followed the project. How did you pick your airfoil and the size and position of the wing?

InfinityAero > Jayhawk Jake
07/25/2017 at 12:58

The airfoil is essentially an Eppler with a rounded off rear foil, since I wasn’t going to be able to get to a fine point with the construction approach I was using; obviously foil is upside down to create downforce instead of lift. Basically flat surface on the top and curved on the bottom.

For sizing, I went with an approximate mock-up of the dimensions of the CR wing from the dimensions I could find online and image comparison— I believe has a slightly longer chord than the CR edition, and it doesn’t incorporate the curvature at the rear of the wing on the CR. I went with the GT-type curvature in the middle (flat section) because there’s likely nothing but turbulent flow for the center of the airfoil based on the design Honda went for their wing, and that would typically be a high-turbulence section on most verts.

InfinityAero > NYankee1927
07/25/2017 at 13:23

That would be a cool experiment for sure! I’ll have to look into the costs to install a pair (or just one side, even, with an assumption of symmetry). Make a run to 75 without the wing, check that dynamic measurement, do the same with the wing, check the new measurement, run the calc. I could then use that, the wing area and the lift equation to calculate the CL of the wing, which would allow me to adjust the angle of attack to dial in a desired amount of downforce for a specified speed. I know it does work— it wouldn’t have sheared the bolt rated for 50 lbs of force in the turbuckle otherwise, but knowing something works and knowing how well it works are whole different worlds.