Drive Smart: What Is Downforce?

Words & Images By Brennell Christian Tan


Downforce in simple terms is the weight of air passing over the surface of an object forcing the object down on the ground. As opposed to aircraft aerodynamics which causes lift, the product of a cars aerodynamics is downforce. The aim of downforce is to provide increased levels of control and grip through a corner to deliver a higher achievable speed along with increased stability through a bend.

Applications...

Air Brake Partially Deployed At 32 Degrees

The newly launched McLaren 650S has a rear spoiler that can be deployed to increase downforce. The 650S is equipped with an air brake (a kind of dynamic spoiler that can be angled to increase downforce and to slow down the car). The air brake can be partially deployed at 32 degrees to increase grip and downforce through a bend. At high speed when the brake pedal is fully depressed, the air brake deploys at 69 degrees to increase drag and downforce on the rear of the car that reduces braking distances up to 20 metres. 

The 2014 Maserati GranTurismo Sport

A modern supercar like the one pictured, a Maserati GranTurismo Sport has a rear spoiler equipped to deliver improved stability and control at its top speed of 301 km/h.  

Pros & Cons Of Downforce

Advantages Of Increased Downforce...

An FiA Formula-E Race Car Of The Virgin Racing Team

As stated, downforce enables a vehicle to travel at a higher speed through a corner while achieving increased levels of grip. Vehicles like GT3 cars and Formula One cars or the newly launched Formula-E cars have front and rear spoilers to channel air over the body of the cars to deliver increased levels downforce. In the picture shown, the Formula-E car has a front spoiler along with a rear spoiler angled downwards to maximise the weight of air passing over the spoiler. The significant weight of air flowing over the car at speed forces the car downwards on the ground, useful for tackling high-speed corners with maximum grip and stability. 

Another product of downforce is drag... On some cars such as the McLaren 650S as previously stated, utilises drag to reduce stopping distances to enable the driver to brake later through a bend or to rapidly haul the car down to a stop. 

Disadvantages Of Downforce...

With higher levels of downforce comes an increased level of drag. Drag is a major role in a cars aerodynamics, drag with its negative effects, reduces the top speed of a car due to the weight of air passing over the car along with the weight of the car itself holding it back. 

In simple terms, higher levels downforce = higher levels drag.

 Weight of air passing over the car at speed + weight of the car at speed 

= Total amount of drag and downforce

A Porsche 911 Carrera S (997)
Equipped With A TechArt Rear Spolier

Drag causes increased wear and tear on a cars components. Downforce causes drag and with the car moving at high-speed, the tyres will experience increased wear and tear. Engineers will also have to build and design engines and powerplants which produce a higher power output to compensate for the increased drag and downforce to increase the performance and overall speed of the car.