TheOtherEric

Having gotten very little out of the other "wing" thread, I thought we could use a thread with some real information about improving our setup. The vast majority of us don't ponder the details of L/D ratios and chord length, but instead buy an off-the-shelf wing and stanchions, then mount it. And I suspect that few people actually try to set the wing angle properly. But what process should we follow for setting the wing angle, assuming no access to a wind tunnel?

I'll take a guess, but I have no idea if this is wise:

1. Ask the wing maker or consult your textbooks for a suggested angle of attack. Let's say the answer is 10 deg.
2. If the wing is mounted low, set the wing angle either flat or a few degrees since the air will already hit the wing at a substantial angle. If mounting high, like near the roofline, set the angle just under your desired angle of 10 deg.
3. Attach some tufts, rig up a camera, and film a lap then look for separation. If the air detaches on the bottom side on the straights, then you need to reduce the wing angle. If the air detaches in a slow corner, you need a gurney flap. If you never see separation, increase the angle.
4. Once the rear is set, add/subtract front downforce depending on balance. E.g. use a longer/shorter splitter.

I'm an aero noob, so please help set me straight.

bobt993

Eric, we went through this last year and got a variety of answers. What we ended up doing is mounting the wing at roof height by first leveling the car on the alignment turns plates, then establishing zero on the uprights. We then added taps for up to 6 positions starting at zero and increasing at what was 2 degs per gradation I believe We then started testing on track. If your going with a big wing, get some more splitter up front. I ended up with the EVO front end similar to what Glen just did.

jrgordonsenior

In additon to what Bob states above, wing angle is very track dependant. At a high speed track like Cal Speedway (my avatar) I run my wing almost flat. At a twisty track like Buttonwillow I'll use maybe 4-5 degrees of wing max. As I look up at Bob's avatar pic I would guess he has about 5 degress in the wing. You may also end up putting more rake into the car combined with a front splitter and perhaps softer front bar settings to offset the understeer effects. It's a lot of trial and error but once you get it setup you'll love the benefits.....

bobt993

JR, are you running the Gurney flap?

Greg Smith

Front aero is almost always going to be the limiting factor, so set the rear wing so the front and rear aero grip is balanced. On track testing will let you known where this is. If the track has a lot of high speed straightaways and not many high speed aero grip corners you're probably going to want to take some rear AOA out.

jrgordonsenior

No but I'm going to install one before my next race which is at Buttonwillow. How about you and if so, did you notice any difference?...

mark kibort

since we dont have access to wind tunnels, what i did was find cars with the same wing that were fast and see where they were set. the cup cars (because thats the wing I have) were all about 5 degrees for the most part. since my car was a little lose, i ran with near 10. wow, it pushed so bad it was amost undriveable. by the next race, I took it down to 5 degrees and added a splitter.now it was better. added a bigger splitter, and added a hood vent. and all was really nice. i started jockying back between 7 and 5 degrees depending on the track. You are right, the roof line will give you an additional 7-10 degrees actual AOA, depending on the car and where the wing is located.

you know from the Gurney flap discussion that the effective change in almost any wing is about the same change in downforce, as it would if you tweaked the wing to a greater angle of attack by near 7 degrees. (based on a 5% GF ,which is about .5")

I think you should start out at 7 degrees or so and see how it feels. you probably will be taking wing out, if you are pushy and dont do anything to the front of the car to get more bite. If you are lose now, the wing will be a god send!

have fun.

Mark

bobt993

I am adding it now. My buddy has it on his 996 Koni Clonewith a Cup wing and it was not magical for him. It turns out he had so many tweaks he was doing it could not be evaluated independently. I have a test day coming up where I can start without, then add it look at the data during the day. If the weather is good, I will bring the car to the event and send you the results.

J richard

Just as a starting point the factory supercup setup sheets give different settings for the tracks in the 2001 season, with all the variables including the "daytona" setup the wing settings are consistently 5deg....

At least for a cup I'd start there and adjust based on handling preferences...

JackOlsen

The airflow at the roofline is about the same as it is two inches above the deck. It's not parallel to the ground. It's much closer to parallel with the back of the car.

I tested with tufts.

mark kibort

And I for one, believe you !

Juan Lopez

Oil is your friend.

Once you have your starting point, put drops of motor oil on the leading edge of the wing and over and under. Go out for a season and come back and study the smears.

Much easier than tufts and no need for video cam.

bobt993

Juan,

Sound's like a smear campaign to me............

Larry Herman

You gotta do it for the whole season?

Gasser

I ran mine at approx 1 degree rake at TWS last weekend and I had pretty neutral handeling. Thats probably an actual AOA of around 11 degrees. I probably could use some more splitter and Ill try that for the next race.
For my other favorite track with much slower speeds and tighter corners, nothing probably matters but Ill try softer front sways, little more AOA in the rear and add the splitter and see where that goes.

At least it gives me something to do.