Title-winning Tech: Brawn GP 2009

Previous season

Honda had invested heavily in the BAR team, before purchasing them in 2006 and renaming them Honda Racing F1. The engine freeze in the mid-noughties hit the Japanese company hardest though, and both Honda Racing F1 and their feeder team Super Aguri struggled financially, with the latter leaving F1 in mid-2008.   

The engineers and senior personnel, including Ross Brawn and Nick Fry tried to persuade Honda management to continue their ownership of the team, saying that they would have an extremely competitive car for 2009. A poor 2008 car meant that their 2009 challenger was prioritised very early on, obviously meaning the team would have more time to make a competitive car, especially with the new technical regulations coming into play for that year. However, they couldn’t convince the owners and therefore were in need of investment to keep the team – and their 700 personnel – in F1.

In December 2008, as a result of the ‘credit crunch’, confirmation came in that Honda had pulled out of F1 – leaving their ‘Honda Racing’ team desperately looking for investment. Step up Ross Brawn who, along with the other senior members at their Brackley base, took control of the team on the 6^th of March 2009 – retaining Jenson Button and Rubens Barrichello.

The BGP 001

The BGP 001 featured a refined front wing, much more so than any of their rivals. It had a conventional two-element flap, but the endplates were very different – with the front wing tips curling down to form the lower half of the endplate – rather than a separate vertical piece added to the wingtip. Having, in essence, no endplate means drag from the front wheels is reduced – as the (high pressure) airflow from above the wing is diverted around the front wheel.

The car had a very traditional shaped nose cone, a testament to lower formula single seater cars in its simplistic design – gradually declining toward the tip at the base of the front wing (miniscule wing supports), as low as the rules permit. Only Brawn GP took this approach - opposing to, for example, the RB5 which featured a high aggressive mid-section dropping down only slightly, allowing more air under the car but increasing drag.

Their splitter (commonly referred to as the ‘tea tray’) on the other hand was very detailed and featured a double plate arrangement, helping the splitter to condition the incoming airflow as it moves toward the floor and onto their innovative diffuser (more on that later).

With Brawn’s Ferrari connections, the team did try to get the Italian manufacturer to supply them with an engine for the 2009 season, however they eventually chose Mercedes power. They went with a similar sidepod style to McLaren, also Mercedes powered, with a wide high inlet giving maximum space to send incoming airflow around the sidepod undercut of the BGP 001. Their sidepods narrow away to a very tight bottleneck at the rear of the car, making the car incredibly streamlined.

Intriguingly the team had already decided to not have KERS while Honda were still in charge, which obviously had the disadvantage of not have that extra horsepower each lap, but did mean that the 25-30kg saved could be used to help the weight distribution of the car – a significant advantage when looking at specific set ups for different tracks.  

Game changer: Double Diffuser

In Formula 1, the key to success is downforce, which pushes the car down into the road, increasing the grip available to the driver.  A Diffuser acts as a vacuum at the back of the car, producing high levels of downforce, with minimal drag. High velocity, low pressure air between the floor and ground ‘diffuses’ into an expansion chamber, slowing the air down, increasing the pressure and producing downforce. This is known as the Venturi effect.

The greater the expansion chamber, the greater the pressure difference – giving more downforce and therefore more grip. Strakes are added to stop the air becoming turbulent and to balance the downforce evenly across the rear of the car. The expansion chamber is curved so that it rapidly expands the air flow, in comparison to a simple incline.  A Diffuser is very important for the aerodynamics of a car as it contributes to around half of the total downforce.

The infamous ‘Double Deck’ Diffuser was first used by Williams, Toyota but most successfully Brawn GP in 2009. In effect it provides more downforce because it has a larger expansion area. The concept involves a normal diffuser and then a secondary diffuser which is fed by air from holes either side of the plank. The air from these holes is then fed up between the diffuser wall and crash structure – acting as a Venturi ‘pipe’. The crash structure has to be aerodynamically shaped (with a normal diffuser the crash structure has no aero effect at all, so is just a simple, normally square, shape). So in essence there are two diffusers, giving a greater expansion area and resulting in much more downforce.

The Double Diffuser was the result of a loophole in the 2009 F1 Technical Regulations, which all the teams knew about, but only the three teams mentioned above actually acted on it – due to fear of it being illegal. This meant, after the FIA ruled it legal, all the other teams were playing catch up and it wouldn’t prove an easy task. It took until after Brawn GP had won 6 out of the first 7 races for Red Bull to mount a serious title challenge. Adrian Newey said "It was a huge amount of work as the car wasn't designed to work with a double diffuser and, in particular, it wasn't an easy marriage with the pull rod rear suspension". Red Bull dominated the rest of the season but Brawn GP held on to win both championships, with Jenson Button the lead driver. 

The incredible story of Brawn GP will go down in history after their incredible turnaround from being in financial disarray at the end of 2008 to winning both championships just a year later.

Would like to massively thank Matthew Somers (@SomersF1) for allowing me to use his Brawn GP Photographs.