Explained: the Lisboa slipstreaming effect

gal41With Felix set to start from pole position in Saturday’s Qualification Race at the Macau Grand Prix, one of the biggest hazards now facing him is the much-spoken-of, but rarely explained, concept of slipstreaming.

One of the most crucial aspects of success at the Macau Grand Prix, slipstreaming is the phenomenon that allows a car to attain a higher top speed thanks to reduced drag when running behind a rival. The longer the straight, the more efficient the effect, which is why the never-ending run from the start/finish line to Lisboa Bend has made Macau the epitome of slipstreaming duels.

The effect means that setting off from pole is not necessarily an advantage, as the leading car will have to cut through the air on its own, leaving a vacuum behind the rear wing and allowing rivals to close up – and potentially overtake – thanks to increased top speed.

This is why the “snake effect” is another frequent feature on the sweeping straight to Lisboa, with drivers weaving across the track as they try to break – or slot into – the tow.

The “Lisboa slipstreaming effect” was what effectively cost Felix victory at the 2012 Macau Grand Prix, as he led off the line in the Sunday finale but was demoted to second as António Félix da Costa shot by at much higher speed further down the straight.

Qualifying this weekend has indicated that the gain of a good tow measures to about 0.5 seconds, with an increase of around 20 km/h over a car running on its own.

Adding further complexity are varying levels of downforce, with some drivers running less rear wing (a smaller angle on the main flap) for increased speed at the expense of grip in the winding mountain section.

Surviving the first sprint to Lisboa, and potentially breaking free from his pursuers in other parts of the lap, will be the key to success for Felix over the remainder of the 2014 Macau Grand Prix.