Williams FW28 Cosworth
Team: Williams F1
Designer: Sam Michael (TD), Jörg Zander (CD), Loïc Bigois (CA)
Drivers: Mark Webber (9), Nico Rosberg (10)
Clearly the biggest transition is the shift away from 3.0l V10 motive power in favour of a 2.4l V8, and in Williams’ case, the new partnership with Cosworth. As power is decreased by this FIA regulation change, all Formula One designers have been tackling a demand for higher aerodynamic efficiency to help compensate. In the case of the FW28, this became a fundamental design parameter for the car and is reflected in many ways across the aerodynamic strategy of the car, visible particularly in the design of the rear wing with its decambered tips. The target in this area was to maintain downforce while shedding drag at the wing tips.
To support this strategy, a tall sidepod concept was adopted which allowed a larger undercut and therefore smooth and efficient air flow to the rear of the car. While designers have been forced to grapple with recouping power losses through aerodynamic efficiencies, the FIA dealt another blow to designers by imposing a new restriction on bodywork to the front of the car, removing the bottom parts of any forward barge boards and, in the process, dramatically altering flow dynamics around the front of the car. The response in the Williams design office has been to pursue a zero keel option to the management of the front wishbones. This area of design has been one of fundamental contention and revision across the Formula One paddock, but the zero keel solution now clearly provides the most efficient aerodynamic solution. In addition, the team has progressed the cascaded front wing, trialled successfully in the last two Grands Prix of 2005.
The revised three part qualifying format, essentially with the first two elements on low fuel and the final session based on race fuel, has had major implications for the approach to 2006 race strategy and in turn, with the design and all-important capacity of the fuel cell.
Equally, the regulators’ decision – after a season of outlawing the practice – to re-enshrine tyre changes has a clear line of influence over the design of the elements of the car that respond to the changing parameters of tyre wear, fundamentally in relation to the mechanical set-up of suspension elements and weight distribution.
If the external factors were not sufficient to keep the design office at Williams busy with the incarnation of the FW28, the technically motivated switch to Bridgestone tyres (which the team last raced in 2000) has demanded a complete revision of weight distribution across the car and a re-formatting of suspension geometry in order to harmonise the dynamic characteristics of the FW28 with the qualities of the Bridgestone tyre. Technical Director, Sam Michael, commented, “The FW28 has been a large departure from previous Williams’ designs due in part to new aerodynamic efficiency targets, but also the mechanical challenges of changing to Bridgestone tyres and Cosworth’s V8 engine. It has been a really interesting car to design and I believe that will continue to be the case during its development in 2006.”
The shift to Cosworth has been another fundamental element in the genesis of the FW28. The development of the CA V8 has been characterised by an open and culturally convergent philosophy between the two organisations, which has been nothing short of positive and productive. As Tim Routsis, the Cosworth CEO reflected, “Following the dramatic shift in the engine regulation landscape, we are approaching an immensely exciting 2006 Formula One season with a mindset of cautious optimism. Our partnership with WilliamsF1 continues to strengthen and the highly motivated nature of the relationship has produced extremely encouraging results since track testing began. The CA2006 V8 was first installed in the WilliamsF1 FW27C interim car in November last year, since when it has completed in excess of 7,000kms of test mileage. Progress achieved so far by Williams and Cosworth validates the expectation of the partnership enjoying a competitive campaign this season.”
Alongside the new V8 powerplant in the drivetrain design strategy has been the progression of Williams seamless shift technology which is anticipated to come on stream in the early part of the 2006 season. This seven-speed, continuous torque gearbox owes much of its development progression to the joint validation work conducted on Cosworth’s dynos in Northampton, indicative of the depth and strength of the technical partnership. Seamless transmission can be worth up to 0.4 seconds over the course of an average racing lap.
Fundamental rule changes and new technical partnerships with Bridgestone & Cosworth have all equated to a heady cocktail for the Williams design team to tackle. However, the FW28 is a first design for Sam Michael’s new combination of Chief Aerodynamicist, Loic Bigois and Chief Designer, Jörg Zander. For the first time too, the design team has had the benefit of two onsite wind tunnels dedicated to the new car from the outset.
The team has progressed the development of the FW28, together with the input from its technical partners, with an added degree of relish over the winter. Although not openly admitted, the extra challenge presented by the rule changes has galvanised the engineers into a mood of positive engagement. This is, in fact, where Williams should be at its best. For Sam Michael the objective is clear, “The FW28 has a lot resting on its shoulders as it must re-establish Williams at the sharp end. There are many good teams in Formula One now and how to beat them is simple – design a faster car.”
The FW28 performed its first validation run on Tuesday 31 January in Valencia, Spain, ahead of its race debut in Bahrain on 12 March.
Transmission: Longitudinally mounted 7-speed transmission, carbon-fibre clutch
Engine designation: Cosworth CA2006
Valves: 4 / cylinder
Valve train: Pneumatic, DOHC
Cylinder head: Aluminium alloy
Engine block: Aluminium allow