HONDA The Power of Dreams

Beginning in 2006, F1 engines were downsized from 3L V10s to 2.4L V8s. Although there had been moves in the past to regulate the engine power wars, this change was a drastic step to curb speed and reduce costs. The 2006 regulations not only changed the displacement and the number of cylinders, but also defined a minimum weight of 95 kg, V-bank limited to 90 degrees, center of gravity height of 165mm or more, bore diameter of 98mm or less, and crankshaft of 58mm or more. Variable intake systems were also prohibited, and the use of special steel materials was banned. The ban on the use of metal matrix composite (MMC) materials, intermetallic compounds, and magnesium alloys directly led to an increase in weight, but Honda achieved an engine weight of 95.2kg, close to the minimum, by using titanium materials optimized through predictive computer analysis. Honda was also able to achieve a center of gravity height of 165.5 mm, just within regulations, by using its existing technology to lower the center of gravity. Being so close to regulation limits created margins to increase the rigidity of the upper mounts and thus the chassis. These techniques increased the car’s lateral bend rigidity by 50 percent.

The most difficult issue was the regulation prohibiting variable air intake systems. Until now, Honda had been using a continuously variable intake system, in which the intake pipe continually moved up and down by around 30mm depending on engine speed, but this was no longer available, making torque control difficult, and an alternative became necessary. The variable intake system is specifically designed to change the length of the intake manifold (intake trumpet) to take advantage of the pulsation of air in the induction box that occurs when each cylinder draws in air, and to push air in when the intake valve is opened. This resonance effect is used to control output and torque. Since this was prohibited, technology was required to widen the engine’s torque band. A splitter (partition plate) was installed in the induction box to change the air interference between the four center and four outer cylinders to achieve flat torque characteristics. With the exhaust system, various exhaust pipe specifications were tested to increase mid- and low-speed torque. In addition, low-loss gear ratios were used in the low rpm range, where torque was low. In the latter half of the season, the effective aperture area was widened by increasing the valve angle, and the intake port shape was developed using simulation technology to maximize dynamic effects, resulting in improved power output.

In June, the team underwent a reorganization, appointing Shuhei Nakamoto, who joined the team in 2002 as Race and Test Team Manager and worked with the team for more than four years, as Senior Technical Director. Soon after that, on August 6, Button clinched his first win at the Hungarian Grand Prix. This was not only Button’s first F1 victory, but also the first win for Honda engines since the 1992 Australian GP, and the first win in 39 years for a Honda factory team, since John Surtees won the 1967 Italian GP.