Features - Technical
FEBRUARY 17, 1999
1999 Formula1 Preview
BY PETER WRIGHT
Why should it be any different from last year, apart from the arrival of BAR and the loss of Tyrrell, and the shuffling of the driver pack? Before trying to predict any changes to the competitive order or interpret the limited indications gained from the guarded presentations of the new cars, it is worth looking at what has changed in the various factors influencing the design of the cars. These can be summarised as tyres and regulations.
The FIA has limited the width of the front wheels/tyres to 355 mm, to stop any increase in overall tread width being added to the cars, and demanded a fourth groove in the front tyres, to slightly reduced their performance. However, much more significant is the withdrawal from Formula1 of Goodyear, thereby calling a truce in the tyre war. Bridgestone, as the sole supplier, neither has to take risks with tread compounds nor has to continue expensive tyre development. The harder compounds that Bridgestone have supplied so far, look as if they will add a couple of seconds to lap times and make the timing of pit stops less critical on some circuits. This "peace dividend" effect far out ways that of the extra groove. Designers, sensitive to the debacle of weight distribution and wheel base variations they were forced into last year, will have concentrated on trying to get it right first time, in spite of different tyres again; those teams with Bridgestone experience have the best chance of doing so.
Having been forced to narrow the track of the cars last year, one would have guessed that designers would have tried to shorten the wheelbase in order to maintain an optimum ratio of track to wheelbase (assuming of course that the ratio was optimised in 1997...). Instead, after the experience of last year, wheelbases are getting longer. Ferrari in particular have not only pushed the rear wheels rearwards, to put more weight on the front axle, but have also moved the front axle forward, thus cancelling that effect and significantly lengthening the wheelbase. The most likely explanation for this design trend is that, if it is not possible to make the cars truly stable, then at least it is better to increase yaw damping by lengthening the wheelbase. The ratio between of the width of the front and rear tyres (355 versus 380 mm i.e. 48:52) cannot be matched with weight distribution (43:57), and the cars are inevitably nervous especially under braking. Increasing yaw damping gives the driver a better chance of catching the car when the back tries to overtake the front.
Some re-arrangement of the main masses, not possible in the middle of a racing season, has enabled a more forward weight distribution without increasing the polar moment of inertia too much. The move to longitudinal gearboxes is complete, with Williams being the final convert. Several cars have followed Stewart's lead by taking the oil tank out of the bell-housing and installing it in the rear of the monocoque, behind the fuel tank or recessed into it. Thus positioned, it allows neater plumbing between engine, oil tank and oil cooler.
At the request of certain Technical Directors, the regulations governing the use of control systems have been re-written in order to clarify exactly what is permitted and what is not. At the same time, the range of permitted devices and their all important algorithms has been limited. It should now be clear that the following are not allowed:
1. Energy storage devices
2. Driver-selectable engine/throttle maps
3. Ignition and fuelling maps that do anything other than optimise combustion
4. Clever anti-stall, anti-overrev, anti-speeding and clutch-control systems that might possibly help driveability or traction control in the lower gears. Indeed, anything that even smells of traction control.
5. Driver-selectable, electro-hydraulic differentials
6. Side-to-side brake balance
7. Active fore-and-after brake balance
The main changes to the regulations, as opposed to clarifications, concern safety and environmental issues. Two new safety features are introduced this year - a wheel-retention system and a driver-extraction seat. Each wheel must be fitted with an 8mm diameter cable attaching the upright to the chassis. The braking load of 50KN means that the cables will be made of a fibre as such as Kevlar and they will be located within the front leg of the lower wishbone. To determine just how these devices cope with accidents, it will take another incident like the first lap at Spa last year to test them.
The driver-extraction seat is to provide the medical teams with the means of extracting a driver with suspected spinal injuries while still strapped into his rigid seat. The seat must be fitted with supplementary straps and quickly releasable seat fasteners. Lear Corporation have shown their product that meets this requirement.
The frontal crash test has been revised, the impact speed rising from 12m/s to13m/s (17% more energy) and it goes up again to 14m/s (another 16% energy) in 2000. In order to make the current nose-box less of a stiletto, and to maximise the energy absorption capabilities, the crush performance has been revised:
1998: Average g <25g
Peak g <60g for 3ms
1999: First 150mm: average g <5g
Remainder: average g <40g
Peak g 60g for 3ms
The clearance over the driver's head provided by the role-over structures, has been increased from 50mm to 70mm, and a requirement that they must also provide 5 mm clearance over the steering wheel has been added.
To improve the environmental image of Formula1, and to back up the FIA's political stance on road car environmental issues, the fuel specification has been brought into line with EEC limits for 2000, with the additional warning that when the Final Directive for 2005 is published, further changes will take place. Most significant are reductions in permitted benzene and sulphur:
1998 1999 2000
Benzene 5%v/v 1%v/v
Sulphur 1000mg/kg 150mg/kg 50mg/kg
There is also a tightening up of permitted quantities of certain hydrocarbons and oxygenates. These changes will give the fuel companies some headaches but are unlikely to affect power output to a noticeable extent.
In spite of some odd definitions of the terms "evolutionary" and "revolutionary", all the cars appear to have evolved from last year's. The only revolutionary feature that is apparent so far is the Benetton's Front Torque Transfer system (FTT), described in RCE V8N10. While other teams fight to have it banned, and presumably develop and test similar devices at the same time, Benetton continue to gain experience using it. Exactly how much benefit it gives only racing will show. If it helps driver confidence when braking, it will provide a measurable benefit in qualifying and assist with overtaking - two vitally important areas.
Benetton have also hinted at a new development in the transmission, but one can only guess at what it might be. Rumours have suggested that a twin-clutch system that ensures no loss of engagement with the engine is a possibility. The benefits of such a system would not be during up-changes (they are so short already as to cause almost no loss of acceleration), but in smoothing down-changes to minimise disturbing the rear end of the car under braking. Pure speculation....
The quest for smaller, lighter and lower engines gathers pace, with 100kg being the new standard by which engines are compared against the Illmor-Mercedes. Mercedes had suddenly become a rather coy about details of their engine's weight and dimensions, even though they have plenty to boast about. Could it be that BMW's imminent arrival has made them more cautious? Power and RPM are now definitely over 800ps at 17,500+rpm, but the actual figures are even more closely guarded.
Ford's purchase of Cosworth has given the company new impetus and they have produced an engine that reputedly challenges the Mercedes for size and weight. It would be good if it also endowed Stewart with competitive power and reliability. Apart from Ferrari, the engine most likely to challenge Mercedes is the Honda. Now that Honda is heading back with an even greater commitment to Formula1 than they had when they were dominant with McLaren, it is unlikely that they will not employ all the expertise of Honda R&D to gain the sort of success they are enjoying in CART racing. After all, beating Mercedes as they have succeeded in doing in the USA, is the reason why Honda is in racing. How else can they compete with Mercedes' image?
That Formula1 is becoming a power race, as chassis performance settles down to the major regulation changes introduced in 1998, is evident as more and more cars are equipped with 7-speed gearboxes. As power becomes more important, one method of raising it is to narrow the power band. Using 7 instead of 6 gears can make it possible to narrow the band by 200-300 rpm. Gear-change times are so short that the penalty of an extra change is minimal and little extra distraction for the driver.
The CFRP gearbox, as used by Arrows and Stewart last year, has not proved reliable enough for others to follow their lead. The problems that they experienced seem to have warned off other teams from following this approach to reducing the weight at the rear of the car. Maybe they are just not ready yet.
Aerodynamics continued to yield 5-10 % improvement per year, but it now costs a great deal to achieve. 50% wind tunnels and $0.5m models are necessary to maintain this level of yield. It is impossible to interpret what all the tiny changes to front wings, barge-boards, rear wheel flip-ups actually contribute to increasing downforce and reducing drag, let alone how they affect pitch sensitivity, without the facilities the teams now possess. What is interesting however, is that they do not understand it all. Benetton, BAR and even Ferrari have suffered rear wing failures in testing their new cars, which are apparently not due to the vibration problems experienced in 1997. This time, at least some of the failures are due to the exhaust overheating the wing support structure - the aerodynamicists do not know, or forgot to study, where the airflow is taking the hot exhaust gases.
Suspensions continue to be refined to improve packaging and installation stiffness. McLaren and Ferrari led the way last year by removing the front suspension units from the top of the monocoque and re-arranging them inside the structure, using longitudinal torsion bars and near vertical dampers. Others now follow. Just as Benetton and Sauber decided to emulate McLaren's steering arms on the wheel centreline (Benetton has to deal with the additional problem of reducing the aerodynamic disturbance of the FTT drive-shafts), McLaren has moved it back up to be level with the top wishbone. At the rear, the compromise between lowering the deck height and keeping the diffuser area around the sides of the gearbox as narrow as possible is still coming out in favour of a narrow gearbox fairing, and so , apart from on the Sauber, suspension units remain on top of the gearbox.
The differences between cars are becoming smaller as the regulations stabilise again and everyone catches up with the teams that designed their cars right first time i.e. McLaren. Hopefully it will be more than a two-horse race this year, though I suspect McLaren and Ferrari to be out front still. The scrap between the Jordan-Honda's, the Supertec-engined Williams, Benetton's and BAR's, and the 800ps, Petronas (Ferrari)-engined Sauber's should be good. I hope Gary Anderson's experience can lift Stewart to join the scrap - that will depend on Ford. Prost's performance will be a function of how determined Peugeot is and how much John Barnard can influence them from the UK. The Arrows and Minardi will suffer from a lack of power and funds, but may surprise on occasions. Here we go again... may be the first race will prove these predictions totally wrong!