'Clever' Mercedes blows hole through aero rules

An F1 season rarely starts without controversy as the teams push the boundaries of the rules and in turn become agitated if they don’t like a piece of technology that they see on another car.

They are often even more upset if it’s something they have rejected as illegal, only to find that a rival has put it into practice. That’s the case with Mercedes’ so-called F-duct, a clever piece of lateral thinking by Ross Brawn’s designers.

The F-duct was last seen in 2010 before the FIA banned driver-operated devices that stalled the rear wing, thereby boosting speed. They were in any case made obsolete by the Drag Reduction System (DRS), which performs a similar function.

The Mercedes W03 contains a system that stalls the front wing by linking grooved channels underneath it to a duct on the inside face of the rear endplate. The hole is only visible when the DRS wing flap that hides it is activated and pops up.

It thus provides a straightline speed advantage whenever the DRS is used — at any stage during practice and qualifying, but in races only when running behind another car. In effect it is a tool for aiding qualifying performance and overtaking.

Rivals believe that since the duct is opened by the driver’s action it is clearly illegal, but after inspecting the system in Australia the FIA acknowledged that it complied with the law.

“Obviously we kept the FIA informed of what we were doing,” said Brawn. “They physically checked the system, they were completely happy with it. Some other teams aren’t quite so happy and are seeking clarification. If the FIA continue to be happy with it, we’ll continue to use it.”

Red Bull team principal Christian Homer was among those to challenge the Mercedes interpretation.

“I think it’s something that we just want clarity on, because one could argue that it’s a switch that’s affected by the driver,” he said. “The driver hits a button and it uncovers a hole, so therefore it’s driver activated, which wouldn’t be in compliance with the regulations.

“It’s a clever system and hats off to them for doing it. The frustrating thing with all these systems is that they will undoubtedly be banned for next year, but in the meantime we are all going to go off and follow that rule.”

“It’s a secondary effect, but it’s absolutely operated by the driver,” Alan Permane of Lotus told Motor Sport. “Mercedes hasn’t invented something; it was there, and other people were under the impression that it wasn’t legal. If this is allowed you’ll see everyone doing it, and it won’t stop there, there are many, many other things that can happen.”

All the top teams are investigating their own versions, and the fact that Martin Whitmarsh made it clear that he thought it was legal is a good indication that McLaren is closer than most to readying its own version.

“Probably what we’ve done is taken the spotlight off the exhaust systems that people are running,” joked Brawn. “Because they are nowhere near what was intended by the FIA! You have to work to the regulations, and if someone can see a clever interpretation, then that’s the nature of our business.”

Clarification was expected from the FIA before the Malaysian Grand Prix, after Motor Sport went to press.