Diffuser

Diffuser is a component that improves the aerodynamics in the underbody area of ​​a racing car and creates a suction effect. With its asymmetrical shape, the diffuser ensures pressure distribution under the underbody and downforce.
== Overview ==
In Formula 1, the use of a diffuser is subject to FIA technical restrictions. The diffuser makes it harder for vehicles behind to use the slipstream. Until the rule change in , the diffuser accounted for up to 70 percent of the overall downforce of the Formula 1 racing car, with a 10 percent share of the total air resistance. Following vehicles get into air turbulence, which reduces the contact pressure. In order to reduce the turbulence behind the car caused by the diffusers and thus make it easier to drive in the slipstream and thus also to overtake, the FIA ​​adjusted the specifications for the underbody for the 2009 Formula 1 World Championship. Article 3.12.7 of the official technical regulations now states: "No body element visible under the car that is up to 350 mm behind the rear axle line may be higher than 175 mm." This change made the previous diffusers into their design and thus their effect was cut, the proportion of the total output was then still about 40 percent.
=== Double diffuser ===
The so-called double diffuser, first fitted to the Formula 1 racing cars from Brawn GP (Brawn BGP 001), Williams (Williams FW31) and Toyota (Toyota TF109) in the season, increased the contact pressure with a second, shorter plate above the actual diffuser. The double diffusor of the Brawn BGP 001 also had a central channel that was not visible from below, which, compared to simple diffusors, provided higher downforce and thus more traction.
The possibility of such a rule interpretation already existed before but brought a real advantage only with the rule change in 2009 to make the diffusers smaller. When the advantages of the three teams equipped with double diffusers became clear in the winter tests before the 2009 season, the discussion about their legality began. Before the first race in Australia, the Ferrari, BMW Sauber, Renault and Red Bull teams protested against the installed double diffusers. However, the responsible race stewards rejected the protest and declared the diffusers to be compliant with the rules. The protesting teams appealed this decision, but the FIA ​​Court of Appeal joined the race stewards in their decision of April 15, 2009, declaring the dual diffusers legal in the final instance. At the , a few days after the FIA's decision, McLaren and Renault started with modified diffusers, the other teams followed suit with new developments. As early as March 2008, Ross Brawn, then Team Principal of Honda F1, suggested making the diffuser regulations simpler and more precise. The double diffuser was banned for the 2011 Formula 1 World Championship.
=== Triple diffuser ===
In the season, Toyota developed a triple diffuser from the double diffuser on its Toyota TF109 model.
=== Blown diffuser ===
Red Bull Racing invented the “blown diffuser” for the 2010 Formula 1 World Championship. In the Red Bull RB6 racing car, the hot exhaust gases were directed onto the diffuser roof.
Category:Terminology