Red Bull is the first team to introduce a DDRS system similar to the one Mercedes is using since the beginning of the season. Lotus is the other team to experiment with such a device but hasn't been able to calibrate their system yet as their system is completely passive and not depended on the DRS.
Red Bull has bravely developed a DDRS system to gain an advantage in the latter stages of the season, since such devices are banned for next season, although the system has really improved their qualifying performance because of free DRS use during qualifying. They tested their DDRS solution in Singapore and raced it as well, but no one found out until this weekend in Japan.
Mercedes’ system works by channeling air through the rear wing endplates to the beam wing and then to the front of the car blowing the front wing elements and reducing downforce and subsequently drag induced by the front wing. Red Bull’s system works in a very similar way but they are not channeling the air to their front wing, instead (it is believed) they are channeling the air and blowing the beam wing to achieve the effect of reducing drag.
When the DRS flap is ‘opened’, it reveals two holes, one in each endplate. Air is then channeled using pipes to the beam wing. In order to make room for the pipes though, the endplates had to be thickened, which is evident in the comparison below.
Furthermore, in order to prevent any air from entering the holes when the DRS is ‘closed’ a small fence (highlighted) attached to the DRS flap is being used.
The drag reduction is evident when we take a look at the speed traps where Red Bull has been at the bottom of since the beginning of the season having an average deficit of 2.5% in top speed to the highest speed trap of qualifying, while in Japan it was only 0.9%.