Aerodynamincs

The same principles which allow aircraft to fly are similar in car areodynamic, but the main focus is to produce downforce instead of lift. So depending on the exact requirement for the application, the set up can be modified to suit top speed (low drag) or high downforce ( higher drag) for the corners. But the ideal set normally is to get the maximum down force the smallest amount of drag.

 Most race cars will have a selection of different settings for the various aerodynamic aids to get the optimum set for the highest lap times, depending on the requirements. While this might not always be the case with normal productions cars, some might be set up to produce real down force ( Ford Escort Cosworth for example). While other are more geared towards fuel efficiency and visual appearing looks.

One of the main Physical forces involved in this is called the Bernoulli Effect  ,fundamentally meaning that if a fluid (gas or liquid) flows around an object at different speeds. The slower moving fluid will exert more pressure than the faster moving fluid on the object. 

The object will then be forced toward the faster moving fluid. So we need to force more air to go under the car creating negative lift (downforce). The harder and faster you drive, the more Downforce is produced and the more grip will be available to the tyres/ tires via the suspension and chassis.In car aerodynamic terms, the desired effect of creating Low Pressure while accelerating air flow results in desired Downforce.

This desired aerodynamic downforce can be achieved in a combination of ways. The easiest way to image this is to turn a Airplane wing upside down. The basic theory is that the faster the car can drive, the more downforce is generated and this pushes down on the tyes/tires of the car and produces higher grip and traction levels. A F1 car can produce enough downforce to drive upside down, so it can produce more downforce then the weight of the car.

While this is desired if you going from 200 Mph into a sweeping corner, on a dragster or car focused on top speed. This extra drag will hinder top speed and more engine Power will be required to propel the car forward.

The aerodynamics of a car can be developed to produce a more slippery designed car also, there will be a point where a car's design with a high downforce level will be good in the corners but will have compromised top speed. This is not a desired Aerodynanic design for production cars as it will lead to higher fuel and tyre/ tire comsumption. It is always a balancing act to get the desired amount of downforce for the corners and also low drag levels for top speed.

Some production car do have active aerodynamics, where a wing pops up at a given speed, or in some cases appears under heavy braking acting as a air brake to stabilise Rear Traction.

A Indy car would probably broadly speaking be generally set up to have a greater top speed then a F1 car, as the F1 car will require greater levels of grip with it's rapid directional changes to reduce lap times rather then comprising the rest of the course for high top speed on the straights. But it comes down to different set ups for different Race courses. But like a lot of components on Race cars, it is possible to adjust the aerodynamic levels of the required downforce to yield greater top speeds depending on the circuit.

These Race Teams normally have huge Budgets and dedicated Engineers striving to continually create more and more effective designs. Sometime we are only talking about 0.1 or 0.2 of a second difference on a lap. But over the course of a Race, this can make the difference between first and second place.

Cd  (Drag coefficient or coefficeint of drag) is a aerodynamic term that describes the car cutting through the air and the shape of the car will ultimately affect the overall top speed. The lower the Cd level, the lower the drag and more aerodynamic efficiency of a cars design (this is focused on Drag and not Downforce).

 Lets have a look at a example.Think of a generally Squared/ Flat car frontal area as a High CD level and a rounded smooth shape as a Lower rated one. A car with a larger frontal area, will require more engine BHP to continue to make the car accelerate and continue to gain speed. As the car continues to go faster, the required power to keep building speed increases signaificantly. 

Drag is proportionate to the square of the speed. So normally a smooth, low frontal area cars will be able to produce better top speeds ( If Engine Power is similar), this low Cd value combined with a good aerodynamics downforce aids will result in a true performance package.

But designers and engineers have a fine balancing act to combine good downforce for the corners and minimum drag for the straights. So you can see that just bolting on that fancy or cool looking spoiler or huge Rear Wing, could have huge affects on the overall performance of your car.That is why Motorsport are so expensive and team end up spending huge sums of money for a compettitive aerodynamic package.

Newtons Law of Motion identifies that " For every action, there is a equal and opposite re-action"

So you can see that there are a lot of benefits that can be made in terms of aerodynamics and Manufactures/Race teams spend huge amounts of money testing in wind tunnels to develop the most efficient aerodynamic designs. It is a ever increasing battle for more downforce for as little drag as possible. 

The 3 main areas of the car which can be developed are: Front Wing, Chassis or under body and Rear Wing, apart from the actual Design of the Car. Learn more about these different areas on this following page.

Racing car wings and aerodynamics have come along way in terms of development since basic ground effects where first applied to cars.In the early days of 1967, cars like the Lotus 49 and Lotus 79 for example. Initially had huge rear wings, which were mounted on the rear suspension and even had cable operated Wings to reduce the angle of attack on the straights to increase top speed. Due to too many accidents these High mounted wings were banned and engineers started to look at other area of the car to create even more downforce. Most of the principals applied where taken from Aeronautical design and modified for use in Motorsport.

Here is a interesting fact: the average atmospheric pressure at sea level is 14.7 psi on all sides of an object, even on our own bodies. By reducing the pressure under the bonnet/hood to 14.5 psi, over an area of just a square yard,we would generate about 260 pounds of downforce (0.20 psi difference in pressure) x 362 (number of square inches in a square yard)= 259.2 pounds of usable downforce. So these small little adjustments can yeild impressive results.

You can see that huge amounts of potential downforce can be generated with a little thought and good design principles. This is a ever ongoing battle for Engineers both in the world of production and Motorsports cars.We have seen some weird and wonderful designs over the Years and the future of all Innovations in car design will always continue to evolve.

Why don't you check out this Video for a Insight into the  fast paced World of F1: