The Brawn BGP 001 is a Formula One world championship winning racing car, designed and built by Brawn GP. It was the first, and only, Formula One car used by the Brawn GP team, used to contest the 2009 Formula One season.The car won eight out of the seventeen Grands Prix it competed in.

It was notable for its unusual "double" diffuser, and its legality was disputed though ultimately deemed legal by the FIA.

The BGP 001 was designed throughout 2008 and 2009 by Honda and then Brawn after the change over. It was designed by Loïc Bigois, in similar respects to all the other cars on the grid with a moulded carbon fibre and honeycomb composite monocoque and a front and rear wishbone and pushrod activated suspension system. Remarkably, it was revealed that the modifications made to the car to accommodate its Mercedes engine saw six inches removed from the rear end, severely compromising the car's center of gravity and by the time the team realized how much the car's balance had changed, there was no time to commission a new design.Ross Brawn also admitted that there were fundamental problems with the car, stating that it was too heavy, and that some of the parts were not good for the car.

Yet the car had one difference, which was focused on the rear so-called 'double-decker diffuser'. The diffuser is at the rear of the car and is a route to get downforce by using the airflow under the car's floor. The BGP 001 had a different central channel to its diffuser with the shape of the structure being used to create advanced type of double-decker design. The diffuser's controversial aspect was the hole in the rear which increases the speed of airflow as it heads towards the higher rear venturi section, where it expands and creates more downforce. Other teams argued that the presence of the hole is against the regulations.

At the first race of the season in Australia an official complaint was launched by Renault, Red Bull and Ferrari against the diffusers of the Williams FW31, Toyota TF109 and the BGP 001 saying that they were illegal. However the race stewards did not share that view and rejected the other teams' complaints. Subsequently the car was cleared to race in Melbourne. The same problem was faced in Malaysia after BMW tried again but failed.

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