HONDA The Power of Dreams

As its name suggests, the MP4/5B is the evolution of the previous year’s MP4/5, but its appearance gives the impression of a major departure from its predecessor. Aerodynamic improvements are particularly noticeable, mainly in the changes to the aerodynamic devices. The side pontoons are flatter and the heat outlets have been improved. To meet the demands from Honda’s new V10 engine with its higher revs and power output, heat exchangers, especially the radiator, were made larger. The basic concept of the chassis, however, remained the same as that of John Bernard’s MP4, and the initial advantage was lost. The MP4/5B inherited the same imbalances of the MP4/5 that had continued to plague Ayrton Senna and Alain Prost, and its shortcomings would be further emphasized.

The pull-rod front suspension adopted by Gordon Murray in the MP4/4 was inherited by Neil Oatley in the MP4/5B. Although the system had the advantage of allowing the damper unit to be mounted in any position, it also had the disadvantage of placing a heavy burden on the upper arm, leading many teams to adopt another system. This layout resulted in a cockpit that was very cramped for the 185cm-tall Gerhard Berger.

The air outlets on the sides of the side pontoons were sized according to the characteristics of the circuit. At Monaco and Hungary, where the average speed was low, the air outlets were opened to the maximum size to improve cooling, but at qualifying and other all-or-nothing races, they were often closed to reduce drag, even if cooling was slightly affected.

The MP4/5B’s most distinctive feature was its diffuser, called the “Batman diffuser” consisting of five semicircular tunnels. This concept had already been attempted by Adrian Newey, who designed the March 881 in 1988, and was merely a development of that idea. However, one of the reasons for its introduction was that the transversely mounted gearbox inherited from the MP4/5, which allowed considerable freedom in the design of the diffuser. The semi-circular tunnel was certainly more effective in reducing stagnation and separation at the edges than a combination of flat plates, and it was also more effective in drawing airflow to the rear. However, this also increases the amount of downforce change when the car’s ground clearance changed. If the car bounced while turning at high speeds, its stability would be severely affected. Bob Bell, the head of the aerodynamics at the time, made the decision to switch to an orthodox design from the Hungarian GP. By reducing the absolute downforce, he had to take measures to reduce the range of fluctuation in the car’s behavior. (For the Spanish GP, the rear of the car was extended by 30 cm, among other modifications).

In terms of chassis performance, the MP4/5B was well behind its rival, the Ferrari 641/2. In the end, like the previous year’s model,the MP4/5B had to rely on engine power. The 1990 Honda RA100E engine improved combustion stability through a change in bore/stroke dimensions. It was characterized by the choice of throttle type, which featured a butterfly valve throttle as opposed to the sliding valve throttle used in the RA109E. As a result, the temporary retention of fuel due to turbulence downstream of the throttle was improved, and the air-fuel ratio was successfully stabilized under all conditions. In addition to increasing power, Honda also excelled at preparing engines with characteristics tailored to different circuits. Starting with Version 1 at the season opener in Phoenix, the engine evolved to Version 6 at Suzuka and Adelaide at the end of the season. There was no disputing that the engine was the most powerful of the year.

At the time, about 10 or so F1 engines were prepared per driver for each grand prix (including qualifying and the race), and more than 200 engines were needed per year. Despite the enormous development and activity costs, Honda was thoroughly committed to engine reliability and drivability. 12,000 rpm was the normal limit for the RA109E, the first year of the V10, and it reached 14,000 rpm for the RA100E. Although there were times when the revs momentarily exceed 15,000 rpm due to over-revving such as downshifting, even this was an acceptable level. The RA100E boasted amazing reliability, that it would not break even when revved to these levels.

The climax of the season was at the Japanese GP at Suzuka. Senna “devastated” Prost to take his revenge from the prior year. The two cars collided on the first turn just after the start and disappeared into the gravel dust, giving Senna his second title. A year later, Senna admitted that the contact was intentional. Of course, the act itself is dangerous and should be frowned upon, but it was such a strong emotion that consumed him for a year after Suzuka in 1989.

McLaren had managed to defend their constructors’ and drivers’ titles, but their car had lost its overwhelming advantage. Without Senna and Honda, it would probably have been difficult to win the titles. However, after Prost left and Berger joined, McLaren was transformed into a highly organized racing team. At that time, Senna was in complete control of McLaren.