Article Written by Joseph Burton-Harris
Open wheel cars that use wings and diffusers are designed to create the highest possible downforce with the least amount of drag. The scientific description and explanation of aerodynamics could go on forever and are highly important if you want to setup up and fine tune the car to optimum performance however this level of focus is not the role of the driver. The driver’s feedback to the engineer is an important contribution to these setup changes alongside data capture to reach these optimum settings. Therefore it is critical for the driver to understand the role of the wing; diffuser and the effects they are designed to give when the car is driven fast.
The first thing you will need to know about aerodynamics is that it all revolves around airflow and speed. The faster you are going the more grip you will have.”
Simplistically, when the speed rises the weight of the car multiplies exponentially. This moves the air forcing the car to the ground. The faster you enter a corner the more grip you will have with the sensation being like a weight being pushed on your head into the ground. The front and rear wing can be made up of many components depending on the rules of the open wheel category.
Common components of the front and rear wing include:
- Main plane– The main plane is the major structure of the wing and one of the most important elements of car aerodynamics. The underside of the wing is fundamental in creating the downforce by allowing air to travel faster below the wing than above creating lower pressure below the wing and higher pressure above the wing. This lower pressure allows the top surface; flaps; extra tiers and gurney lips to push downwards creating aerodynamic downforce.
- The front main plane is more efficient than the rear as it is so close to the ground creating more airspeed under it. If the underside of the main plane is not set correctly it will stall or in other words not allow the air to flow fast enough to create the lower air pressure and downforce you want to go fast.
- Flaps or Plates– These are extra pieces of wing that not only increase downforce but are also used to direct the airflow in certain directions to maximise downforce and minimise drag. The flaps/plates are often adjustable and are used by teams to fine tune the amount of downforce. You will often see flaps directly in front of the front and rear tyres to push the air over the tyre due to the tyre being a rough surface that increases drag.
- Gurney- A gurney or ‘wick’ is used at the tip of the rear wing that flicks the air in order to generate that small amount of extra downforce at the rear.
- Side wing end fences– These are usually fin type wings that are facing the same direction as the car. You will see them hang off the edge of each side of the wing. They are designed to direct airflow from the front wing to the rear wing and then directly out the back in-between the two end fences/side wings of the rear wing.
- Louvers– Louvers look like gills which are often located on the rear side wing end fence and are used to direct the air onto the main plane.
- Winglets– Winglets are fin like objects often located on the side pod to direct air to the rear wing or out the side of the car.
- Diffusers are designed to help evacuate the air in a controlled manner to create a suction effect to literally suck the car to the ground. They are connected to the floor tray of the car and are a critical component to create downforce.
- Fins: Fins are used in the modern day high tech categories like Formula 1, Indycar and even LMP1. The fin is a thin horizontal piece that sits on top of the engine cover. The fins prevent the car from pitching hard in a turn as well as making the car more streamlined reducing drag.
When you’ve got too much front wing: The immediate thing you will notice is the sharp rigid effect the car will have going down the straight due to that big front wing catching all the air and throwing the car from side to side while going over the bumps and through wind gusts. Making relatively small turns on the wheel going down the straight will feel like big yanks instead.”
The major thing you will notice is oversteer BUT how do you know if the oversteer is a result of the mechanical setup being wrong (Caster, Camber, Toe, springs) or the Aero being setup wrong? One way to tell is if the oversteer gets worse the faster you go – then you know you’ve got too much front wing. The other thing I have noticed with too much front wing is that the car will break away in the rear very easily when braking.
When you’ve got too much rear wing: The Immediate thing you will notice is that the steering wheel will feel like a slug. Major inputs into the wheel will have very minimal effects creating a feeling of major understeer. Once again the one way to know it’s aero and not mechanical is that the faster you go, the more understeer you will feel.”
Wind is a massive factor in open wheel racing that is often underestimated. The wind direction along with the wind speed has a MASSIVE effect on the handling of the car. If you come in with the car handling better in some corners than others the first thing you have to do is check the wind direction and speed. With those big wings; a crosswind gust mid corner could quite literally blow you off the exit. Wind can significantly affect braking and the speed you enter certain corners. Head winds allow you to brake later; tail winds are asking you to brake a little earlier. Corners with a cross wind blowing in an opposite direction to the corner will cause understeer mid corner to exit so keep that in mind!
Contact: Wings are the arms of an open wheel car… Any contact and you could lose one: a flap, end plate, winglet or even the whole wing main plane itself. Unless you can get a new one during a pit stop your race is generally over, so definitely apply all your skills to avoid contact. As a famous driver once said ‘if you no longer go for a gap you are no longer a racing car driver’ (Senna). There will be occasions where contact is inevitable as in all forms of racing. But as long as you learn good spatial awareness and treat your wings like gold then you’ll be right.