Honda RA106 | F1 | Racecar Engineering (original) (raw)

Since buying out BAR in late 2005, Honda has been developing its RA106 chassis. Super Aguri took it on for 2007

First published in 2007

Victory. When Jenson Button's Honda RA106 crossed the line in first place, it was the high point of a very mixed season for the works team. Honda had bought British American Tobacco out of the BAR F1 team in November 2005, and become a 100 per cent works team. Honda's involvement in grand prix racing has brought it much success as an engine manufacturer over the years, netting many race wins and a handful of world championships, too. However, as a full manufacturer, Honda has only claimed three victories, including that one in Hungary. Work towards the 2006 season started in 2004 when it became clear that Formula 1 was to switch from 3.0-litre V10 engines to smaller, less powerful 2.4-litre V8s. Honda already had some experience of building racing V8s for the IRL but those units would be little help in developing a 20,000rpm Formula 1 screamer.
The first prototype engine was run in the back of a development car at Mugello in September 2004, so the team could gather data on performance and the effects of the increased vibrations caused by a V8 on the surrounding systems. The engine development project team was run under Kazuo Sakurahara, who revealed to RE:
'The most worrying problem would be a level of engine vibration which the design team had never experienced before.' The vibration issue could potentially have lead to a range of problems that would keep both the engine and chassis design teams busy. Design of the RA806E, the eventual full race engine, started in January 2005 and it first ran in July of the same year. 'The initial concept of the engine was to create a package with greatly improved body joint rigidity, which would surpass the V10 in terms of power-per-litre running at full revs in the opening race of the season. Then the focus of the development stage was to try and solve the vibration issues inherent in a V8 engine,' explains Sukurahara. The new engine regulations would limit the freedom of Sukurahara's team on overall architecture of the engine, and also the materials they could use. It had to be a V8 engine of no more than 2400cc, with a V angle of 90 degrees. Only two inlet valves and the same number of exhaust valves would be permissible. The regulations were tight and very restrictive, even the cylinder spacing was fixed at 106.5mm (+/- 0.2mm). A really difficult part of the regulations for the designers, however, were those regarding the engines centre of gravity, as laid down in article 5.5:

5.5 Weight and centre of gravity:
5.5.1 The overall weight of the engine must be a minimum of 95kg.
5.5.2 The centre of gravity of the engine may not lie less than 165mm above the reference plane.
5.5.3 The longitudinal and lateral position of the centre of gravity of the engine must fall within a region that is the geometric centre of the engine, +/- 50mm. The geometric centre of the engine in a lateral sense will be considered to lie on the centre of the crankshaft and at the mid point between the centres of the forward and rear most cylinder bores longitudinally.