Red Bull RB9 - passive double DRS 13 March 2013
At the final pre-season test in Barcelona, Red Bull experimented with a passive double drag reduction system (DDRS). The top red arrow in this drawing indicates the small inlet duct that - above a certain speed - feeds airflow up a vertical channel to blow under the rear wing's main plane. This partially stalls the wing, leading to a reduction in drag and thus a small speed increase. Unlike active DDRS (banned in 2013), the driver has no control over the system, and if it proves unpredictable he could find himself robbed of valuable downforce at inappropriate moments - at the start of a braking phase for example. Until teams get a proper handle on this behaviour - a long and delicate process, if testing is anything to go by - no one is likely to race a passive DDRS, at least in the initial rounds of 2013.