Survival race

Formula One fans can look forward to more cut and thrust on the track as new rules turn the sport into a laboratory for hybrid vehicles and help protect it from green critics. Dan Thisdell reports

Formula One motor racing boils with an intoxicating mix of speed, noise, glamour, money and truly fabulous engineering. Proof enough is its massive world television audience and the season’s expansion from its traditional European fixtures to new events in Malaysia, China and Bahrain.

However, paradoxically, for many fans the sport has a stronger reputation for excitement in off-track politics and intrigue than it does in racing. Words such as “procession” and “Scalextric” are all too often used to describe the action, with races seemingly decided by qualifying and team tactics rather than wheel-to-wheel racing.

One of the most persistent criticisms of F1 is that there is so little passing. Whether that is down to the layout of modern circuits, sophisticated aerodynamics or the stifling effect of the huge budget gap between the leading teams and the also-rans, it’s fair to say that many fans would welcome more cut-and-thrust on the track — and they may get plenty come 2009.

The FIA, motorsport’s governing body, has laid down new technical regulations that will turn F1 into a technology laboratory for hybrid vehicles.

The rules will move F1 from today’s highly-optimised cars powered by 2.4-litre V8s to cars with that same power plant supplemented by an energy recovery system capable of boosting horsepower by about 10 per cent in short ‘push-to-pass’ bursts. With a short development timeframe before the 2009 season, it is anyone’s guess who will be winning races – and in what sort of machine.

Pit stop: as the result of the new rules the focus of technological development will shift from the engine to the Kinetic Energy Recovery System

The FIA is changing Article 5 of its F1 technical regulations, so ‘engine’ becomes ‘engines and Kinetic Energy Recovery Systems’. The current generation of 2.4-litre, 32-valve V8s, putting out about 650bhp, will remain but be limited to 19,000 revolutions per minute.

The focus of technical development will shift from the engine to the kinetic energy recovery system – or KERS. That device will be allowed to take in or release power at a maximum rate of 60kW (80.4 bhp) and release as much as 400kJ on any one lap. The KERS could weigh up to 20kg and release of its energy must be under the complete control of the driver at all times. In practice, the driver might have access to as much as 13 seconds of boost per lap which, on a typical circuit, takes about 100 seconds.

Behind this radical shift in the rules is what the FIA regards as an imperative to keep F1 relevant to modern vehicle engineering.

When FIA president Max Mosely first spoke about the KERS concept last summer, he acknowledged that a green image could be valuable to F1 if there was a serious fuel crisis. Politicians, he reckons, might ban or restrict motorsport as a visible gesture but would be unlikely to do so if it was helping develop important technologies. Hence he prefers the term ‘modern technology’ to ‘green technology’.

More urgent, in Mosely’s calculations, is the need to keep automakers involved. He noted that, at present, the quickest way to get more power out of an engine is to increase its revs.

But while squeezing a couple of hundred more rpm out of an engine already doing 19,000-plus is effective on the racetrack, it does nothing to improve ordinary road-cars, that operate in a range up to about 5,000rpm. Hence it is easy for a carmaker to wonder if it should really be spending millions on F1 engine development.

Energy recovery, however, is important to every carmaker. As he said at the time, there are six automakers involved in F1, ‘and the ones that are finishing sixth-best are going to need a good reason to stay in. Developing energy-efficient technology helps justify their involvement’.

Whether hybrid technology as F1 might develop it will spin off to make better road-going hybrids is debatable, though. Richard Adams, Motor Industry Research Association spokesman, said racing- and road-cars have hugely different operating requirements that make hybrid spin-offs a more difficult proposition than simply getting the cost of an F1 technology down enough to make it economical for road use.

Hybrids such as the Toyota Prius take advantage of the fact that, most of the time, road-cars operate at part-throttle. When the hybrid’s battery needs charging, the car’s engine management system can choose to throttle up and split the internal combustion engine’s output between the drive wheels and the generator, without the driver noticing. Battery reserves are thus maintained to power the supplementary electric motor when it is needed.

Racing cars and road-cars have hugely different requirements making it hard for the F1 hybrid technology to spin off on better road-going hybrids

But, said Adams, as racing cars tend to be run with the throttle either wide-open or fully closed the only opportunity to charge batteries would be during braking, when a huge amount of power is dissipated as heat. Unfortunately, batteries cannot accept a lot of power quickly, so the road-car solution of using regenerative brakes at the wheels to feed power into a storage battery is not viable in F1. Adams added that putting regenerative brakes in the wheels means added unsprung weight, which would be a racing non-starter.

Moreover, the flip side of batteries’ inability to receive large quantities of energy quickly is their inability to release it in great surges.

NiMH and lithium-ion batteries are better and lighter than lead-acid, but these are technologies more suitable to a milk float than a racing car, said Adams. A better solution for fast charge and discharge is a super-capacitor. These devices, however, cannot store as much energy as a battery and issues with weight and durability will challenge F1 engineers who look to go this route.

Mechanical solutions — probably using a flywheel to store energy recovered during braking — are another way to go. When F1 cars were turbocharged, the turbos ran in the 100,000-150,000rpm range and Adams estimates that an F1 flywheel system would have to turn at those speeds. At the moment, though, such flywheels do not exist in a size and weight range that would be suitable.

‘I don’t think there is one, single, obvious answer,’ said Adams, and nobody would disagree with him when he says we should expect a range of solutions on the starting grid in 2009.

The challenge raised by KERS is neatly summed up by Pascal Vasselon, Toyota F1’ssenior general manager for chassis, for whom the big question is whether to store energy in a flywheel or a batter or super-capacitor: ‘[These] two systems will be fighting each other in two years’ time. It’s difficult to know exactly where it will go,’ he said.

To Vasselon, flywheels look like the better option. But, he said, the rate of improvement of the electrical system seems so steep that it will be difficult to disregard. He suggested that a battery or super-capacitor could be easier to fit into the car, as they can be built in many shapes while a flywheel would inevitably be box-shaped. ‘At the moment we are looking at all the different technologies and we will try to delay our decision for as long as possible,’ he added.

Dave Greenwood, chief engineer for advanced technology at Ricardo Engineering, agreed with Vasselon that flywheel storage looks more suited to the 60kW/400kJ parameters than do battery- or super-capacitor solutions.

A flywheel could be charged and discharged mechanically from the drive shaft, or used as a flywheel battery connected to an electric motor on the drive shaft. A flywheel battery accelerates when power is put in from a motor/generator on the drive shaft and acts like a dynamo generator to take power out. This system has the advantage over a direct link because the flywheel does not have to be mounted at the engine.

Any flywheel system for F1 would have to overcome a number of technical challenges but one is tempted to conclude that a flywheel battery arrangement is the elegant solution to the KERS conundrum.

It would be ideal if bearings were developed that could operate in a vacuum at several hundred thousand rpm while being subject to intense shocks, heat and vibration. That would also call for a containment system that could ensure an exotic composite flywheel stayed in place even in a crash.

According to Greenwood, ‘these ifs are very big ifs.’ He added that 60kW electric motors that are small and light enough, and able to withstand the harsh conditions found in an F1 car, cannot be pulled off the shelf. If F1 teams do develop flywheel battery systems, he said the spin-offs for road cars in electric motors and power management electronics could be significant. Greenwood sees the lowest-risk alternative as being the more conventional electric motor and storage battery or super-capacitor option, even if size and weight considerations mean the system gave less power than the regulations allow.

As implied by Toyota’s Vasselon, the big teams will probably go down multiple development routes, reckons Greenwood. The system any team develops will depend on its strategy — does it want a system to give a boost coming out of each corner to improve lap times in qualifying, or is it looking for a big surge to overtake, or prevent overtaking?

Management, he added, has got to line up the right technical partners, cut exclusive technology deals and put enough resources into different options early on to be able to choose the best option as late as possible. ‘Given the tight timeline for development I think there’s going to be some exciting racing in 2009,’ he said. ‘No one solution is jumping off the page.’

Cosworth, the Northampton race engine maker that is probably the most successful in F1 history, considered the KERS problem carefully last year while it was still supplying power to the Williams team.

According to race engineer Simon Corbyn, hydraulic motors, possibly integrated with the gearbox, could be the most easily deployable solution, partly because all F1 teams have experience with high-pressure hydraulic systems while none are experienced with high-voltage electrics.

He readily admits, though, that hydraulic motors are also the least flexible alternative and, while they have been shown in principle to work as a drive system, it is not clear they would improve an F1 car’s performance. In any case, he said, integrating the engine and chassis is a critical aspect of KERS development, as packaging of any system is challenging, and flywheels more than most. For instance, the gyroscopic effect of a flywheel on vehicle dynamics has to be considered, he said, adding that it might even be possible to use it to advantage.

Corbyn also urged F1 to take particular note of the safety implications of KERS. Teams will have to consider how stored power is to be discharged when not needed, and which team members will have new roles in the pits and garage.

Also, race marshals will have to know how to handle stored energy when responding to crashes. ‘If each car has a different solution it might look like the Wacky Races,’ warned Corbyn.

All of these issues will surely be resolved by the teams taking part in this furiously competitive sport because, as Toyota’s Vasselon pointed out, there is a real incentive to develop a KERS system.

He said that a system done properly without too much weight penalty would be worth close to half a second a lap, or at least four-tenths. ‘If we can package it without too heavy a weight, it can work,’ he claimed.

To put those four-tenths in perspective, at last month’s Malaysian Grand Prix the first 10 places in qualifying were separated by less than 1.2 seconds. On some circuits – especially the most prestigious of all, Monte Carlo – overtaking is so difficult that the winning strategy is to qualify on pole position and avoid any gross errors during the race.

F1 development engineers, it seems, are in for a wild ride.