HONDA The Power of Dreams

The 2003 RA003E was significantly lighter, which inadvertently caused reliability problems and had several issues during the season. Durability was improved, but in the end, an increase in weight was inevitable. The Honda staff were discouraged, but also learned what was needed to build an engine that was lighter and unbreakable. The RA004E was the result of this experience.

The first step taken as project leader by Takeo Kiuchi, who had returned to F1 after a 10-year absence, was to make the development team understand the reality that Honda’s engines were heavier and underpowered compared to the top manufacturers. He then told the team not to give up before it tried, and he would be responsible for their challenges. The most important theme for engine development in 2004 was to improve reliability. The one-engine-per-weekend rule, which began in 2003, would become one-engine, one-race-per-week from 2004, which meant that engine life had to be significantly extended to an expected 800 km per unit.

For this reason, the design of the RA004E engine was once again changed drastically. The bore x stroke of 97 x 40.52mm was retained, while the overall length was shortened to 581.5mm. This was shorter than the 588mm during Honda’s first two years back in F1 (2000-2001), not to mention the 600mm of the 2002 and 2003 engines. The center of gravity was also significantly lowered from 177.2mm in the previous year to 171.6mm. This innovative reduction in size was largely due to the use of siamese cylinders. The direction of coolant flow was changed from cross flow in each cylinder to flow along the length of the engine, and the distance between bores was shortened to 6mm. Piston material was an aluminum-metal matrix composite with high fatigue tolerance at high temperatures, and the unit weight had been reduced to 210g. In addition, the clutch mounting was changed, and laser-clad valve seats were adopted to improve downsizing, center-of-gravity balance, durability, and reliability. These development efforts contributed greatly to weight reduction, with the RA004E weighing a further 8.1kg less than the RA003E’s 90.9kg. Maximum rpm finally exceeded 19,000 rpm.

This lightweight and compact engine allowed the heavier parts to be concentrated in the center of the chassis, reducing the moment of inertia and improving the car’s handling in the corners.

In 2004, Jenson Button, in his second year with BAR, was joined by Takuma Sato to race for the team. Sato had filled in for Jaques Villeneuve in the last round of 2003, the Japanese GP, and finished sixth. He was promoted to full-time team driver in 2004, his first full-season F1 seat in two years. Anthony Davidson, the third driver, supported both drivers. This year, teams other than the top four in the previous year’s constructors’ championship were allowed to run a third car in Friday practice, and BAR, which had finished fifth in the previous year’s rankings, was able to run a third car with Davidson at the wheel to gather more data for the weekend.

The various challenges began to pay off, and in Round 2, Malaysia, Button finished third, and became a regular podium-finisher battling for the top positions throughout the season. Teammate Sato also finished third in Round 9, the U.S. GP, becoming the second Japanese driver to be on the podium. With a total of 11 podium finishes, BAR Honda moved up to second place in the Constructors’ Championship. This result further increased the team’s awareness and upward momentum. This was the first time since Honda’s win in the 1992 Australian GP, and since it came back to F1, that the team felt it was within striking distance of victory.