Tech Analysis: Honda RA107

It is a much more settled Honda team that steps into 2007, a team that is taking an aggressive approach to build on the maiden victory that proved to be the highlight of a mixed year in 2006.

The team started last season in turbulent fashion, with reliability and aerodynamics issues leading to a technical reshuffle and technical director Geoff Willis' split with the team. Around the same time the head of aerodynamics, Willem Toet, departed for BMW Sauber.

Willis was replaced by Honda man Shuhei Nakamoto, who was later joined by Jacky Eckelaert from BMW Sauber, and while there are two sides to the argument of why Willis left the team, it was clear the old structure placed too much emphasis on one person. The new approach has seen more people are empowered to make decisions and inject new ideas.

This new philosophy, according to Nakamoto, will allow the team to be more aggressive and imaginative in the coming years. And, importantly, as a manufacturer-owned team, it is a breath of fresh air. Most often, large corporate companies try to stamp their mass production values onto the F1 design team, with poor results. If Honda can make a manufacturer team operate as effectively as a more conventional team then progress will be made.

In developing the new RA107, its predecessor, the RA106, has been used as a basis. Although the team struggled with that car in early part of 2006 they were back on the pace and reliable by the end of the season, problems with aerodynamics and tyre behavior during a race seemed to be solved and it provides a good starting point for 2006.

Last year, as a Michelin team, Honda already had a long gear case but this year the new car gains an even longer gearbox. The carbon fiber construction of the case is probably beneficial in retaining low weight and stiffness for such a long component.

The complex winglet arrangement (yellow) sits in the tighter coke-bottle shape © Scarborough (Click image to enlarge)

The case still contains the Honda R&D developed seamless shift gears, now in their third year of racing, so although they have no fears for their unit's reliability, the lap time advantage it gave them is now lost as all other teams have adopted similar designs.

The longer rear end will aid weight distribution, but the greater advantage is that it allows more space for sidepod shaping. This is an area to which Honda has put a lot of thought this year, and the resulting sidepods are radically different to the other teams' designs.

Most other teams try to create as much undercut as possible and then mount the flip-up high, scooping up the flow passing under the raised nose and speeding it towards the top of the diffuser to improve the downforce created at the rear.

The Honda design, in contrast, is far less undercut and the sidepods also mount the main flip up much lower. In this, Honda seem to have taken the opposite approach, although the position of the very large pod wing spanning both the upper and lower halves of the sidepod probably acts to keep the flow passing over the diffuser with the same force.

Honda developed more extreme pod wings in 2006, with ever larger fins mounted to the front shoulder of the sidepods. CFD images released of their 2006 car showed the fins collected the clean fast flow from under the front wing, which would otherwise have gone wide around the sidepods, and sent it towards the rear wing. Meanwhile, the dirty flow around the wake of the front wheels was kept clear of the rest of the bodywork by the fins.

Space has been created above the sidepods both by the lower flip-up and by bringing the sidepod closer into the engine and gearbox. The tighter rear end has been a result of the exhausts being pushed forwards and the radiators being moved the currently favored flatter position. This narrower coke bottle shape has been filled with a complex winglet set-up.

While most teams sport a chimney with a simple winglet, Honda have added a wide double-decker arrangement. The upper section is a conventional twisted two-element wing, while below mounted to the same endplates is another two-element wing, this time being angled to the airflow, but untwisted.

This design looks to create a lot of downforce, but doesn't appear to be very efficient. However, with low drag still a consideration for the team with the lower powered V8 engines perhaps the winglet combination sits low enough not to create as much drag as it appears. In the car's first tests the wing required a temporary strut to stabilize the assembly.

For 2007, the steering arms now sit in line with the upper wishbone © XPB/LAT (Click image to enlarge)

At the rear of the car Honda still support their wing with two struts and below the diffuser the car sports the Ferrari-like extra channels to the side of the taller middle tunnel.

Change at the back is also matched with some changes at the front, with a slimmer nose that is currently unmatched to a new wing. Last year's front wing was being tested along with the endplate-mounted cascades in initial tests but This will no doubt change in the next few weeks before the first race.

Another detail at the front concerns the front suspension arrangement. Last year the team adopted a zero keel arrangement for the front suspension that moved the inboard ends of the wishbones much higher. As a result steering rack was placed midway between the upper and lower wishbones and although the steering arms sat in the airflow, this design kept the weight of the steering rack low down.

This year the zero keel has been retained, but the steering rack has moved upwards to contain the steering arms in line with the upper wishbones. The suspension has also had to be re-optimized for the Bridgestone tyres.

Honda's version of the twin keel probably helps them over some other zero keel teams, as their lower wishbone mounts under the nose nearer the cars centre-line, where as other teams have their mounts to the side of the monocoque. This creates unequal length wishbones, which might allow Honda to find the ideal settings for roll centre position and camber gain.

Allied to the revised gearbox, Honda has further developed their V8 engine in line with what is permissible under the new engine-freeze regulations. Last year the team's engine development diverted mid season to create an all-new engine in time for the FIA cut off October. The engine struggled for reliability at first but completed its race distances in time for the homologation process to begin and over the winter the tuning for the rev limit of 19,000rpm has been completed, combined with improvements in drivability for engine speeds below the upper limit.

So, be it the result of the key technical staff change or to the new Honda philosophy, the car is visibly different from its predecessor and it is clear to see new thinking has gone into its design. Having gone for a dramatically different aero philosophy, however, it is difficult to predict how the Honda's pace will be affected this year.

Certainly reliability and the way in which the team manages the new tyres will be just as crucial. Early testing has shown some reliability issues, but with everyone learning to handle the new Bridgestone tyres, Honda may well have the break they need to get out of the cycle of bad form they've had for two years.