Influence of Anti-lock Braking System on Drifting

by Yin Chen, Clemson Automotive Engineering Graduate Student

Basic Description

Drifting started as a sport in Japan in 1990s, as a racing technique with both utility and aesthetic values, it became more and more popular and spread to western countries in the past decade. Since drifting is kind of sport with safety risks, in modern vehicles, the action of drifting may have conflict with systems such as the anti-lock braking system (ABS) and the electronic stability control (ESC). In this project, some basic techniques of drifting are introduced and the effects of ABS on drifting are discussed.

Drifting Background Information

Drifting is a driving technique where the driver over steers the vehicle intentionally in order to cause the rear wheels to lose traction through the turn. As the diagram below shows, a loss of traction of the rear wheels causes the vehicle body to swing out. Drifting is the art of maintaining control of the vehicle under these conditions in order to navigate the course quickly.

Usually drifting requires a rear-wheel-drive car (FR, MR or RR). While it is also possible for a front-wheel-drive car to drift, the techniques available are very limited.

Effects of ABS on Different Drifting Techniques

Drifting can be classified into two different techniques, clutching and braking. Based on these different techniques, the ABS system exhibits different effects on the vehicle. For clutch-based drifting, a rear-wheel-drive car is necessary and basically there are two ways to make the car drift; clutch-kick drift and shift-lock drift.

• The principle behind the clutch-kick drift is to make the rear wheels lose traction using a power surge of the engine during shifting. There won’t be any lock-up of the wheels during the drift, thus the ABS system has no effect on clutch-kick drift.
• For the shift-lock drift method, the back wheels are supposed to lock-up in order to initiate a drift. But in modern vehicles that are equipped with ABS, the brake of the wheel will pulse on and off in this situation, and this may block the development of a drift or make it choppy.

Brake-based drifting is more basic than clutch-based drifting and can be divided into the three categories shown below.

• The E-brake drift is a basic drifting technique; initiating the lock of the rear wheels by pulling on the emergency brake. Because wheel speed sensors are installed in both rear wheels for those cars with ABS system, so that a real lock up can never happen and which means the E-brake drift technique is difficult on vehicles with ABS system.
• For braking drift, the mechanism is a little different from the E-brake drift. Through applying the brake, the driver lets the vehicle weight move to the front wheels which makes the rear wheels lose traction resulting in drift. During this kind of drift, in most cases the wheel will not completely lock up, thus the ABS system does not have a big influence on this technique. It seems to be the only feasible drifting technique that a front-wheel-drive car can use. The control of braking drift requires more driving skill and is much more difficult than the E-brake drift.
• The long-slide drift technique uses almost the same method to make the car drift as the E-brake drift. And it requires a greater slide distance and a higher cornering speed. Based on the conclusion drawn from the E-brake drift, it is obvious that making an ABS equipped car finish a long-slide drift will be even harder.

For More Information

[1] How Drifting Works, Julia Layton, HowStuffWorks.com.

[2] Drifting (Motorsport) , Wikipedia.

[3] Forzacentral Forum, Forzacentral.com.

[4] Drift Japan Blog, Drift Japan.

[5] How Anti-Lock Brakes Works, Karim Nice, HowStuffWorks.com, Aug. 23, 2000.

[6] Anti-lock Braking System, Wikipedia.

[7] Questions and Answers Regarding Antilock Brake Systems (ABS), National Highway Traffic Safety Administration (NHTSA) web site.