Toro Rosso STR4

Bourdais 2009 Spain

Sebastien Buemi 2009 Singapore 2

Toro Rosso STR4 was a Formula One racing car designed and built by the Scuderia Toro Rosso team for the 2009 Formula One World Championship. It was the successor to the STR3 and was driven by Sébastien Buemi and Sébastien Bourdais, with the latter being replaced by Jaime Alguersuari midway through the season. The STR4 was a significant car in the team's history, marking the end of Toro Rosso's practice of using chassis designed by its sister team, Red Bull Racing, following the introduction of new regulations that prohibited customer cars.

Design and Development

The STR4 was closely based on the Red Bull Racing RB5, adapted to fit the Ferrari engine used by Toro Rosso, in contrast to the Renault engine used by Red Bull Racing. This required modifications to the car's rear end, including the gearbox and cooling systems, to accommodate the different dimensions and cooling requirements of the Ferrari engine. The car featured a double diffuser, which became a controversial and pivotal design element in the 2009 season, offering significant aerodynamic benefits after being deemed legal by the FIA.

Racing History

The STR4 made its competitive debut at the 2009 Australian Grand Prix. Throughout the season, the car showed flashes of competitiveness, with Buemi scoring points on his debut in Australia. However, the team struggled to consistently challenge for points, reflecting the highly competitive nature of the 2009 field and the team's limited resources compared to the leading teams.

One of the highlights of the STR4's racing season was the performance of rookie driver Sébastien Buemi, who managed to score points in several races, showcasing his talent and the car's potential in certain conditions. The mid-season replacement of Bourdais with Alguersuari also marked a significant moment for the team and the car, as Alguersuari became the youngest driver to start a Formula One race at that time.

Legacy

The STR4 was the last car Toro Rosso used that was based on a Red Bull Racing design, as new regulations from 2010 required teams to design their own cars. This marked a significant shift in the team's approach to competing in Formula One, moving towards greater independence and the development of its own technical capabilities.

The performance and development of the STR4 during the 2009 season played a crucial role in this transition, providing valuable experience and data that would inform the design and construction of future Toro Rosso cars. Despite its challenges, the STR4 is remembered as a key part of Toro Rosso's history in Formula One, representing the end of an era for the team and the beginning of a new chapter in its evolution.