Stewart-Ford SF-3 -- Ready To Go!

STEWART-FORD SF-3 Ready to go! A clear statement of the Stewart-Ford team's intentions for the 1999 season was to be found at Silverstone's south circuit on the morning of Wednesday, 23 December 1998. For it was here, against a backdrop of the...

STEWART-FORD SF-3 Ready to go!

A clear statement of the Stewart-Ford team's intentions for the 1999 season was to be found at Silverstone's south circuit on the morning of Wednesday, 23 December 1998.

For it was here, against a backdrop of the foulest winter weather Britain could muster, the Stewart-Ford SF-3 turned a wheel for the very first time - fully 10 weeks before the opening race in Melbourne.

The plan for SF-3, agreed with Cosworth Racing engineers in early 1998, was for the car to be launched early to avoid some of the problems experienced with SF-2 and to allow for sufficient testing, development and car build time before the Australian Grand Prix on 7th March.

In essence, the SF-3 is a completely new car. Every aspect of the mechanical and aerodynamic package has been subject to review and improvement. In addition, significant change has been made possible by the introduction of the Ford-Cosworth V10 CR-1 engine.

The SF-3 represents major improvements over SF-2 in every respect. The increased SGP Design and R&D capability has enabled the car to be ready early so as to maximise pre-season testing and evaluation time. This will be even more crucial in 1999 given the reduction on testing under the FIA Technical Regulations.

The new engine is a significant step forward in terms of car packaging and could easily be the lightest and smallest on the Formula One grid in 1999.

The short overall length has allowed for more scope in terms of positioning major components for optimum weight distribution. It has been possible to lower the centre of gravity of the car considerably, again helped by the low crank height and also by a concerted design effort to place components in favourable positions. We have also been able to lower the front of the chassis dramatically and the position of the driver's torso some 30mm.

To achieve the lower forward chassis has meant a complete revision of the spring/damper/steering assemblies. The new design is based around horizontally mounted torsion bars. Every link of the front suspension has been produced 'in-house' from composite materials.

The SF-3 retains some of the innovative features of SF-2 including the centralised oil system. The composite gearbox, on the other hand, proved troublesome in 1998 and with reliability in mind we have reverted to a magnesium version for SF-3. For packaging reasons we have also reverted to coil springs at the rear of the car and at both front and rear we opted for a central spring unit. Custom made dampers systems designed in conjunction with Penske Shocks are also new to SF-3.

As the SGP Design and Manufacturing staff has grown and gained collective experience we have been able to concentrate much more on structural issues in particular the stiffness of chassis, gearbox and suspension assemblies. This is an on going programme which has already yielded significant results aided by the input from resident engineers from the Ford Motor Company.

One of the areas of Ford Technical Support we have high hopes for is that of Vehicle Dynamics. Using Adams software and other proprietary analysis tools we are working towards a much better understanding of overall suspension characteristics and maximising the performance of the tyres.

The aerodynamic package as seen on the launch car has been focused on maximising performance from the major elements of chassis and body packaging. This effort has yielded improvements in efficiency over the SF-2.

An extensive aerodynamic programme is ongoing and will mean gains in overall downforce and driveability by the time of the first race.

One area of extensive development in recent months is the Visteon VCS electronics package - a 'one box' system catering for engine management, chassis control and data logging. This state-of-the-art system has already provided increased capability over previous systems.

The same resource will also allow a development programme to proceed through the season, something which was very difficult to achieve in previous years. This program is already underway and in addition to the aerodynamic issues already mentioned it includes a new version of the composite transmission housing and rear suspension packaging.

The Ford-Cosworth V10 CR-1 engine already out performs its predecessor on the dyno and the development potential inherent in the design will see it equal to the best during the season to come.

The FIA Technical Regulations are basically the same for 1999 with the exception of the front tyre being required to have four grooves rather than three and Bridgestone being given the brief to produce harder compounds.

The objective is to get in amongst the top four or five teams in 1999 and the improvements in the car and the technical progress of the company as a whole should allow the Stewart-Ford team to achieve that objective.

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Series Formula 1