Anyone who has been watching Formula One this year will have heard the term F-duct. This mysterious system—the brainchild of the McLaren engineers—caused a mountain of controversy going into the first race of the season at Bahrain.
McLaren’s MP4-25 was noticeably faster in a straight line than its competitors and it was all thanks to a clever piece of aerodynamics known as the F-duct. It allows the drivers to control, at least partially, the way that air flows over the rear wing and, in doing so, reduces the amount of drag that the wing produces.
One of the things that enables F1 cars to go as fast as they do through corners is the down-force produced by the various wings (technically aerofoils) that are bolted all over the car. The downside to this, is that these very things that make it fast through the corners actually slow the car down in a straight line.
The F-duct changes the way that air flows over the rear wing and can be controlled by the driver, effectively changing the effect of the wing on long straights, reducing drag and making the car faster.
The explanation is a whole heap of stuff from high school physics lessons about air travelling faster over one surface than the other creating pressure differentials (it’s actually not really that simple, but you get the idea), and air from the duct changes all that.
Because this is F1, everyone immediately complained about how the system was illegal. Also because this is F1, everyone was working frantically one producing their own version of the system. Mercedes now have one, as does Ferrari—it won’t be long before everyone in the field is in on the act.
These innovations are what sets F1 apart. Contrary to popular belief, not many of F1’s innovations make it through to road cars, they are focused towards getting an extra two or three tenths of a second per lap.
Things like ground effects skirts and active suspension were great leaps forward in the F1 world. More recently, we had the Brawn split diffuser in 2009 and this year we have McLaren’s F-duct.
Interestingly, Red Bull Racing are suspected of having a system that changes the ride height of their car as the fuel load burns off. While everyone in the F1 paddock is suspicious, the details of the system have yet to come to light.
Such has been the focus on McLaren’s tricks that Red Bull’s speed advantage has gone almost unquestioned. Once the F-duct issue has been sorted out, however, that will almost certainly change.
*As luck would have it, just after publishing this article the teams voted to ban the f-duct for the 2011 season.