F-Duct uncovered: The banned McLaren innovation that gave birth to DRS

Uros Radovanovic
Lewis Hamilton drives a McLaren car during F1 testing

McLaren F duct: A great innovation for the F1 2020 season

When unveiling their car for the 2010 season, all eyes were on McLaren, despite their efforts to keep it low-key.

This was due to the now-famous F-Duct, a project that would be remembered as one of the most creative ways to enhance a car’s aerodynamic performance while staying within the rules.

Here’s the story of McLaren’s project, which was essentially a DRS system before the DRS system existed.

The McLaren F-Duct idea

When they first revealed their car, the McLaren F1 team hoped the event would pass with minimal attention.

However, a small inlet appeared on the car, its purpose unknown, and whether it complied with the rules was uncertain. Such a detail was hard to go unnoticed, instantly making McLaren the main topic among journalists and F1 teams trying to figure out what was happening.

During that time, the philosophy of car aerodynamics was different. Unlike today, the car floors were flat and simple, with the front and rear wings playing a significantly bigger role. Teams invested the most money and time in developing these aerodynamic components.

Since the DRS system didn’t exist yet, much more attention was paid to the impact of drag on the car. The ideal scenario for every aerodynamics engineer was the ability to magically control downforce and drag levels during a lap – maximum downforce for corners and minimal drag for straights. Achieving this was impossible, as increasing downforce would automatically increase drag.

However, McLaren engineers found a way to control these two forces to some extent while staying within the rules.

The McLaren F-Duct explained

At first glance, the F-Duct system seems simple, but achieving its effective functionality was undoubtedly challenging. The project was named after the location of the main inlet, next to the letter “F” in the logo of the then-primary sponsor Vodafone.

The entire system consisted of a series of pipes or passages inside the car that directed air. The first part of the system was a small inlet where air would enter at high speed.

After that, the pipe divided into two directions – one leading the airflow to the driver’s cockpit and the other extending to the rear of the car.

The driver controlled which of these two channels the airflow would take. By covering the cockpit inlet with their elbow, the air would simply continue towards the rear of the car. Otherwise, the air would enter the cockpit, not disturbing the car’s aerodynamics. The crucial part was above the engine.

In this section, the channel split again into two directions, towards the rear wing and towards the part where the car’s exhaust was located.

If the driver blocked the entry of air into the cockpit, directing it along the upper path, this airflow would later come into contact with the air coming from the airbox and redirect it towards the rear wing.

This disrupted the overall aerodynamics of that element and caused a stall. This meant that the profiles of the rear wing were no longer as effective, generating significantly less downforce, and simultaneously less drag.

This way, McLaren drivers had the ability to reduce drag when it suited them, primarily on straights.

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Development of the McLaren F-Duct

The FIA quickly confirmed that the F-Duct was entirely legal. Although movable aerodynamic components were prohibited at the time, the driver activated this system, giving the FIA no grounds to ban it.

Moreover, McLaren and other teams improved this system during the season and adapted it to specific tracks.

The power of the small inlet was evident in the team’s strategy at Monza that year. McLaren decided to test two entirely different aero setups for that race – Hamilton drove a car without the F-Duct and with a low-loaded rear wing, while Button had the F-Duct and a much more aggressive rear wing.

This unconventional approach brought Button excellent top speeds on straights and good grip in corners, securing him second place.

Additionally, some teams quickly copied the concept and implemented it in their own way. Sauber, for example, added a small inlet on the sidepod, while the rest of the system was practically the same. They were the first team after McLaren with an F-Duct, introducing it as early as the second race of the season.

Other teams soon joined, including Mercedes, Ferrari, Red Bull, Force India, and Renault. Ferrari quickly abandoned the entire system because they couldn’t implement it properly into their already designed car. This was McLaren’s advantage that other teams couldn’t catch up with.

The end of the F-Duct

The F-Duct system was alive for only one year before being banned, mainly due to safety concerns and to prevent additional investment in this system. McLaren finished the 2010 season in a high second place.

Despite the innovative and creative ideas, the overall performance of the car was not sufficient for the top spot. However, many argue that McLaren inspired the FIA, leading to the introduction of the DRS system the following year.