Wings

Wings are conceptually quite simple. Their implementation on the F3 is less straightforward due to the many aerodynamics elements.

Adding wings and increasing their angle (higher numbers, referred to as “more wings” from now on) will slow the car down more and more. You can test this by putting your hand out of the window in a passenger car. Tilt it so that the palm goes from parallel to perpendicular to the asphalt and you will feel your hand being increasingly pushed back (and downward/upward, depending on its inclination).

Adding wings, thus, slows the car down… which is bad.

However, just like wings push an airplane up in the air, they are designed to push a car down towards the ground. This is good for racing.

More wings add “apparent weight” to the car by pushing it down (downforce), this gives more grip; a good thing.

You may want to imagine that grip is related to the friction force which, in turn, correlates with the perpendicular load (weight), thus more wings lead to more grip. You can also test this by sliding an eraser on a table. Hold it gently and it will move; push hard on it and it will be more difficult to make it slide.

Grip to the front (more wing to the front) leads to oversteer.
More wings and thus grip to the rear lead to understeer.

Imagine a car with no grip at all on the front wheels (steering wheels), for instance because they are up in the air. The car simply won’t turn. Similarly, moving grip away from the front provokes understeer.

With the above in mind it is rather easy to use wings to tune the car.

  • If you need more grip: add wings – both front and rear.
  • If you need more oversteer: add wings to the front and/or remove wings to the rear.
  • Do the opposite if you need understeer.
  • If you want to go faster: remove wings – both front and rear.

Keep in mind that more wings will provide more grip under braking, allowing shorter distances, and partially under acceleration, increasing traction.
I write “partially” because:

wings have larger effect the higher the car speed.

F3 Wing Settings

For simplicity, let us put “aero package” and “front flap configuration” to “High DF” and forget them for a while.

Front Wing
There are two settings for the front wing.

Front flap: increasing the angle gives “more wing”, with all the above implications.

Front flap gurney: an element added to the back of the wing to increase downforce. You can choose between 0 (no element), 5 and 10mm. The gurney flap is not aerodynamically efficient, I am told by people in the know. It is worth using only when seeking more downforce than the front wing can provide near its maximum angle (see below for more). However, I am told that one F1 world champion preferred to use gurneys front and rear in slow corners; this was “by feeling” rather than being supported by data.

Rear Wing
There are two elements, “upper flap” and “beam angle”. Increasing their angle provides “more wing” and thus more rear grip at the price of slower speed.

Aero Calculator

This section allows to quickly change wing configuration, for instance to add more grip if you find yourself on a slippery track, without altering the overall aerodynamic balance.

It also allows finding the most efficient wing settings.

Front and Rear RH (Ride Height) at speed
These numbers do not alter the setup, they are only used for aerodynamic calculators. The real numbers can also only be obtained through telemetry (more on this on the “ride height & rake” page); they are not identical to the “static ride height” shown in the chassis page of the setup.

Change the front and rear wing to see the numbers below change. It is actually easier done than described.

Drag trim
It gives an indication of how much drag (resistance) your wings are generating. Higher numbers mean more drag, which slows the car more.

Downforce trim
Similar to the above, higher numbers represent more (total) downforce. Good for grip.

Balance trim
How much the aerodynamic balance is moved forward in comparison to the base configuration.
Higher numbers (positive) mean more downforce to the front (more front aero-grip, oversteer).
Lower numbers (negative) mean less downforce to the front (less front aero-grip, understeer).

Finding Your Settings

Start tuning your aerodynamic setup by looking at the balance trim.

Set your wings; go on track; take note of the car behaviour in mid to high speed corners. If you are feeling oversteer, go back to the pits and change the wings so that the balance trim becomes lower (use less front wing or more rear wing). Do the opposite if you need more oversteer.

When you find a balance that you like take note of the value for the balance trim (eg -1.0 %).

Now you like the car balance, but maybe would like to have more/less downforce, for instance because you are in a session with low/high grip due to high/low track temperature.

In the pits, add/remove front and rear wing so that the “balance trim” remains roughly the same, but the downforce trims increases (more downforce, more grip) or decreases (less downforce, less grip).

When you have a downforce level you like, try changing the two rear elements (and possibly the gurney, although it is seldom, if ever, used) so that the downforce trim number remains the same, while the “drag trim” decreases (less drag).

Aero Package

You can select High, Medium and Low DF (DownForce) aero packages. The Medium DF can also select either Low or High DF front flap configuration. These represent different aerodynamic “pieces” attached to the car.

Unfortunately you can not compare downforce and drag trim between different packages. 10 downforce trim points in the High DF package do not correspond to 10 points in the Low DF package.

I have not extensively explored this; please let us know if you have more information and I’ll edit this part. I only know that the car has lower top speed with 25 rear wing in the MDF than 11 rear wing in the HDF, suggesting that you have less downforce and drag in the HDF low wings configuration.

Downforce to drag
This number is rather important but very difficult to analyse without telemetry, since it depends on the ride height.
It provides an indication of the aerodynamic efficiency of the car. Higher numbers indicate that you are generating more downforce per amount of drag, which is always a good thing.

Aerobalance
Another important number that, however, depends on the ride height. It gives an indication of the front to rear ratio of aerodynamic downforce. Higher numbers indicate more front downforce. It is easier to judge this with the “balance trim” which does not require ride height information. However, keeping the same balance trim but altering the ride height will alter the actual downforce balance.

Gurney flap
You can see the effect of the Gurney flap by following the downforce and drag trim values, in addition to the downforce to drag numbers.

Put the rear and front wings to the maximum. Now add the gurney flap. Decrease the front wing one click at the time and you will notice how initially the downforce increases without increasing drag. For lower downforce trim numbers, however, using the front wing without gurney gives less drag trim.

Wings drawings and information from page 30 onward of the F317 owners’ manual.

Aerodynamics of Race Cars – Scholar article on the subject.

Further Reading
Drag and Downforce Trim points are probably linked to the Drag and Lift coefficients (CD, CL).
See image, taken from the above pdf link.