With the additional downward force, the only way the forces will add up to zero is if the normal force increases. This means that the friction force is greater, so the new acceleration is greater.
Now, instead of obtaining a maximum acceleration of 6 to 7 meters per second squared, it is possible to obtain much higher values, perhaps 15 or even 20 m/s.2. The McMurtry Spéirling in the video went from 0 to 60 mph in… wait for it… 1.4 seconds. Just thinking about it will make your ears freeze.
The idea of fans is not new. In 1978, the Brabham BT46B used it to win the Swedish Formula 1 Grand Prix, but it was quickly banned. However, the idea of increasing downforce is still alive. Today, F1 cars channel airflow through the bodywork in clever ways to achieve some of the same “ground effect,” justified by saying its purpose is to cool the engine.
While these airflow systems help cool the engine, everyone knows that the real purpose is to generate low pressure under the car to get it closer to the road. In fact, the new McLaren W1 we recently reviewed is a road car which makes it the selling point. (You can buy one for $2.6 million, or you could have if you’d signed up in time. McLaren only makes 399.)
The good thing is that this increased acceleration is not just to increase your speed. It also allows the car to brake faster and even make tighter turns, as these are also types of acceleration. Downforce can turn a fast car into an incredibly fast car, if that’s what you want. For me, I’m happy as long as it’s a red car and it drives.