The 'double DRS' debate

Sky Sports F1's commentary expert Mark Hughes on how Red Bull's new system compares with those on the Lotus and Mercedes.

Behind the dramatic turning of the championship battle that Sebastian Vettel's victory in Japan provided is a relentless development war - one that has sparked the Red Bull's 'double DRS' system that caused so much interest at Suzuka. It was actually first raced two weeks ago in Singapore and works differently to the similarly-labelled systems on the Mercedes and Lotus. What it has in common with the Merc is in how, when the conventional DRS flap is used by the driver, holes are exposed on the inner face of the rear wing endplates which take in air through hollows in the endplate, re-directing it elsewhere. But it redirects it to a completely different place to the Mercedes - to the rear beam wing, not the front wing. The beam wing sits between the diffuser and main wing and when the re-directed flow from those internal channels hits, it induces the whole airflow to pass over it in such a way that the drag is reduced. This new flow in turn also induces the airflow over the diffuser to stall, thereby lowering drag yet-further. So there is a three-stage drag-reducing hit rather than the single-stage of a conventional DRS. Lotus conducted further experiments with its own 'drag-reducing device' in the Suzuka practices, but it was again dropped for qualifying/race. The question has been asked how come Red Bull was able to introduce its system immediately while Lotus has been trialling its 'drag reduction device' for half the season and it's still not been raced. But the comparison is not a valid one - because the Lotus system will still be legal next year whereas those on the Red Bull and Mercedes will not. The essence of the difference is that the Red Bull and Mercedes systems only operate when the driver activates the DRS whereas the Lotus system operates regardless of whether the DRS flap has been activated. The FIA has chosen - from 2013 - to interpret the Red Bull/Mercedes systems as 'driver-activated' drag reduction. From next year that can only apply to the DRS flap itself and not any secondary or tertiary drag-reducing devices. The Lotus system takes in air from inlets either side of the engine box above the cockpit and feeds it either to the beam wing and brake ducts (increasing downforce and also drag) or to the corners of the rear wing (reducing downforce and drag). The point at which the flow changes from one route to the other is not directly connected to how the DRS flap is being used, but just to the air pressure within the system. That is why it has proved so much more difficult to get working. The fact that Red Bull has researched and developed such an aerodynamically complex system that can be used only for the last seven races of the season is a little tell-tale that Red Bull believes this title to be winnable. Lotus, on the other hand, appears to be thinking more about 2013. The 'discovery' of the Red Bull system was made at Suzuka, the same event at which the team returned to 2011 levels of domination, which has led to the prediction of that domination continuing at all the remaining tracks. It doesn't necessarily follow, though. For one thing, McLaren has its own system under development. For another, the system was also on the Red Bull at Singapore, a race Vettel won - but only after the retirement of Lewis Hamilton's McLaren when leading. The extent of the RB8's superiority around the long fast corners that comprise much of the Suzuka track was in keeping with a car that was fastest through Spa's Eau Rouge, for example. None of the remaining tracks place quite as much emphasis on that strength as Suzuka. But what is very clear is that the obliteration of Alonso's comfortable points cushion from the combination of his first corner accident and Vettel's win means Ferrari now desperately needs a more productive development programme. A week ago it was in a position to cruise and collect its way to the title in a car that was adequately competitive. Now it isn't. Mark Hughes