HONDA The Power of Dreams

The 1988 season marked the end of the 1.5L turbo era in Formula 1.

In 1989, the transition to 3.5-liter naturally-aspirated (NA) engines would be complete. 1988 was, however, a transitional period, and while NA engines were permitted to compete, turbocharged engines were subjected to strict regulations. The maximum boost pressure was lowered from 4 to 2.5 bar, and the maximum fuel capacity was lowered from 195L to 150L. In contrast, there was no fuel load limit for cars powered by 3.5L NA engines.

The phasing out of the turbocharged engines was well known, and Honda was ready to respond, as it had begun research and development of the NA engines in 1987.

For Honda, the choice for the 1988 season was to either continue research and development of the severely restricted turbocharged engine, or to compete with the newly developed NA engine. After much deliberation, Honda decided it was worthwhile to continue R&D on the turbocharged engine. This decision was not based on the assumption that rival engine suppliers would shift their focus to developing NA engines, but rather that R&D was boundless, and a strong will that the company should pursue the technology as far as possible. This was Honda’s challenging spirit in action, its philosophy of advancing technology advocated by Soichiro Honda.

Honda would continue to supply engines to Lotus, as well as McLaren replacing Williams. Honda was well aware that there was a high risk of problems arising when matching the chassis and engine for a team it had only recently partnered with.

The engine Honda supplied to the two teams was the Honda RA168E, a 1494cc water-cooled V6 twin-turbo engine, the result of research and development that had incorporated every conceivable improvement at that point in time.

Aiming for both improved power output and fuel economy, the RA168E adopted a long stroke design with a cylinder diameter of 79.0mm and a stroke-bore ratio of 0.643, which had been used since the RA166E. The combustion chamber was formed as compact as possible with a 32-degree valve angle and flat top pistons, resulting in a compression ratio of 9.4. Parts of the turbocharger were magnesium alloy, and the engine had been lightened to 146 kg when fully equipped, through reviewing its specifications and dimensions.

The turbochargers’ blades were ceramic, with ball bearings for improved response. To prevent head-knocking, a special fuel consisting of 84% toluene and 16% n-heptane was developed. All operating conditions were reviewed, including boost pressure, intake air temperature, fuel temperature, fuel mixture concentration, fuel injection volume, and ignition timing, and computer control was optimized for every situation. As a result, the maximum output was 685 hp, according to a published technical report.

As expected, numerous issues arose when matching the engine with the McLaren chassis, but Honda overcame these issues by proposing solutions that involved chassis technology. As a result of these efforts, the McLaren MP4/4 powered by the Honda RA168E won 15 out of 16 races in the 1988 season, demonstrating its relentless strength, with a winning percentage of 93.75 percent.

The RA168E helped Honda to win two consecutive drivers’ titles, and three consecutive constructors’ titles, steadily building the era of the Honda F1 engine.