BMW Sauber F1 Team
2007 FIA Formula One World Championship

Chassis - BMW Sauber F1.07 – a cast of experts.

Compared to its 2006 predecessor, work on the BMW Sauber F1.07 concept began in April 2006 and took shape as part of a close cooperation between the chassis experts in Hinwil and their colleagues in Munich responsible for the powertrain, i.e. the engine and transmission, and the electronics. Priorities were set out from day one and all the aspects of the project brought together to create a harmonious overall package.

“We have channelled our experience with the F1.06 into the new car, but at the same time focused on the new challenges presented by the 2007 regulations”, explained Willy Rampf, Technical Director of the BMW Sauber F1 Team.

To this end, the most significant change is the switch to a single tyre supplier in Bridgestone. In accordance with the stipulations of the FIA, the Japanese company has produced tyres which offer less grip as a means of lowering cornering speeds.

“It’s clear that the cars are going to slide around more. It was therefore important for us to build a car that is easy to drive and that our drivers can trust sufficiently to go on the attack”, added Rampf, giving an insight into the team’s development strategy. “We should also expect the cars to run with rather greater downforce as a rule, in order to make up for the loss of grip.”

 
The nose has it.
Aerodynamics has been a key area in Formula One for a long time now, but the advent of the single tyre supplier format in 2007 will raise its importance even further. “If you look at all the components which affect the performance of a Formula One car, aerodynamics represent – by a distance – the single most important factor”, emphasises Rampf.

All of which explains why the BMW Sauber F1 Team top brass gave the expansion of the aerodynamics department top priority. The team’s use of the wind tunnel in Hinwil was gradually increased, with a move initially from one to two shifts, and from there to a round-the-clock three-shift system in late October 2006. This has given the team parity in this area with its rivals – who have long had comparable systems in place – and fulfilled a central requirement in achieving its ambitious aims.

As always, the key is to enhance aerodynamic efficiency. However, almost as important this year is the need to develop a package that functions as well as possible through corners. Here, the front wing has an influential role to play, largely dictating the flow of air around the front tyres. It has been completely newly developed and forms a harmonious unit with the likewise totally new nose section, which is shorter and sits higher than its predecessor. This results in a reduction in its weight, but also places extra demands on the engineers when

it comes to passing the FIA crash tests. The most important aspect of this development, though, is that the wing channels a large amount of air under the car, allowing the underbody and diffusor to work to their full potential.

New cooling concept.
The cooling intakes are somewhat larger than those on the 2006 car and represent part of a new cooling concept which is more effectively integrated into the overall package and designed to ensure greater air throughput.

The air is diverted upwards to maximum effect, improving aerodynamic efficiency compared to last year’s car, especially in high outside air temperatures. As Rampf explains: “We took a lot of time in the conceptual phase to find the best possible solution in this area. This is an important point, as the air temperature at the first races of the season, in particular, are traditionally very high. The cooling concept of the F1.07 promises to deliver impressive efficiency in all conditions.”

Slimmed-down rear.
The designers built on the knowledge gained with the F1.06 in the development of the rear, giving the tail an even slimmer and lower profile in order to further optimise the air flow around the rear wing. The basis for these modifications is provided by the compact quick shift gearbox and cleverly positioned hydraulic elements. Also integrated into the design are the exhaust pipes, whose form was defined to maximise performance and fit harmoniously into the overall package.

The section underneath the rear wing is a totally new development. More stringent regulations governing rear-end collisions have meant that the rear crash element is now more voluminous overall and also has a modified form. The lower positioning of this element has required a totally revised design for the centre section of the diffusor.

The engineers were also instructed to reduce the car’s weight, while maintaining its rigidity. The affects the monocoque, which is made up of up to 60 layers of carbon fibre in places, as well as individual components. “It’s always good if you can use a lot of ballast, but in the situation we have now it’s particularly important, as it ensures outstanding flexibility in terms of weight distribution. And that plays a critical role in the optimum use of tyre potential”, explains Rampf.

New suspension elements.
The construction of the suspension elements is totally new and, at the front axle, dictated primarily by aerodynamics. The raised nose section mean that the wishbones slant downwards at a striking angle. The kinematics have been modified in response to the introduction of the standard Bridgestone tyres.

“We were also very keen to give the steering a high level of feedback”, says Rampf. “This area has gained even further in importance as a result of the cars’ reduced grip levels. The harder tyres will, by definition, cause the cars to slide around more, which means the drivers will have to do a lot more correcting as a result. And that makes good steering feedback indispensable.” The rear axle was also modified to further improve traction.

Greater comfort.
Comfort and Formula One make uneasy bedfellows. And yet, one of the focal points in the development of the F1.07 was an increase in comfort. This is expressed specifically in the seating position of the drivers, especially that of Robert Kubica. The Pole’s 184-cm frame was a far from comfortable fit in the 2006 car, whose cockpit area was particularly tight. As Rampf points out: “We only have restricted room for manoeuvre in this area, but we’ve done what we can to give Robert a pleasant seating position in the new car.”

There has also been progress in the area of electronics, which combine the workings of the chassis and powertrain in the interests of integration. The electronics for the chassis, engine and transmission have now been brought together into a single control unit, whose space-saving design allows it to be accommodated in the cockpit without taking up too much room.

“We created a solid basis for this year’s car in our first season on the grid. The cooperation between the team members in Munich and Hinwil is now working well, and the additional resources give us extra potential. Our aim is now to further reduce the gap between ourselves and the top teams”, said Rampf, looking forward optimistically to the new season.

The BMW Sauber F1.07 - Technical Data

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