Features - Technical
JANUARY 7, 1996
Cheating the Technical Regulations
BY PETER WRIGHT
In the highly competitive world of motor racing everyone knows how to make the cars faster, but it is forbidden. The stakes may not yet be quite as high as running hooch, but the incentive to win at any price has occasionally tempted participants to push the interpretation of the regulations over the edge, and sometimes to deliberately step boldly over.
In Formula 1, 1000+ bhp engines; "rocket" fuel; ground effect aerodynamics combined with wide, sticky tyres, generating nearly 5g cornering and braking; fan cars; actively controlled wings, suspension, brakes and traction, incorporated into cars weighing less than 480 kg, have all been sampled and their performance potential experienced. To be able to use just a small portion of that potential offers the means of gaining an advantage. Where there are only small differences between the cars, as in many classes of racing such as Formula 3, Formula 3000 and Touring Cars, the temptation to cheat is just as great, though the rewards may be smaller.
There are as many ways of cheating as there are regulations, but they fall neatly into the same categories as those that govern the performance of a racing car: Power, Weight, Aerodynamics, Tyres and Driver Aids.
Power: The maximum power produced by an internal combustion engine is a function of the rate at which oxygen passes through the engine and the amount of energy released by the combustion of fuel with that oxygen, less the losses in the process, and in converting it into a useable form i.e. rotational power.
The rate at which oxygen passes through the engine is a function of the swept volume of the engine, its RPM, the volumetric efficiency, the pressure and temperature of the intake gasses, the proportion of oxygen in those gasses and the proportion of oxygen in the fuel. The amount of energy released in the combustion process is controlled by the calorific value of the fuel and the amount that can be fully combusted with the available oxygen, in the time available.
Losses include: Mechanical friction, pumping losses, windage losses in the crankcase and the power needed to drive the auxiliary systems necessary for lubrication, cooling, fuelling and ignition.
To limit power the Technical Regulations must control one or more of these key parameters governing the performance of the engine. To cheat them means contriving a means of circumventing that control.
· Swept volume: How many oversize engines have been built and raced over the years? This cheat used to have a reasonable chance of escaping detection, as measuring an engine was a tedious task that could not be performed at the circuit. Now it can, using sensors introduced through the spark plug hole.
· RPM: Electronics have enabled an RPM limit to be imposed on all engines used in a Formula - the Monk system in Formula 3000 has proved to be hard to beat, though there were several competitors who thought that it would be possible to bypass it in the early days of it's development. None were actually caught. The problem with cheating an RPM limit is that a tuned ear (or frequency analysing sound recorder) will catch you at it.
· Pressure: Various methods have been devised to limit intake pressure. On turbo engines a pop-off valve is used. Short of meddling with the mechanism, the only real way to cheat is to try and pass so much air through the open valve that the pressure drop raises the pressure upstream in the induction system.
· Orifices: Recent events in the rallying world gave a graphic example of what can be done to bypass intake air around a sonic orifice. In NASCAR racing - probably the most tightly restricted class of racing in the world, whose roots lie with those hooch runners of the Prohibition days - small, engine oil pressure activated pistons have been used to lift the carburettor away from the manifold, letting in air past the orifice plate. "Leaky" manifolds are quite common.
· Ram air: In 1994 an attempt to limit the ram air pressure in Formula 1 led to some incredibly elaborate, airbox arrangements in attempts to regain a little power. In the end everyone involved realised the fruitlessness of the exercise, and full ram pressure was re-instated, along with the advertising space on the sides of the airbox.
· Temperature: The charge air density, and hence oxygen content per intake cycle, is raised if the air temperature is lowered. The most effective way is to use high latent heat of evaporation constituents in the fuel, such as alcohol's, that cool the charge as they evaporate. Not all racing has Formula 1's Gas Chromatography to watch over the fuel used. Water injection, as used extensively on Second World War supercharged aircraft engines, has a similar effect, and is not permitted. It is also probably too complicated for the gains to be worth the risk of being caught.
· Oxygen content of intake gases: Nitrous Oxide (dentist's laughing gas) mixed with intake air can provide enough extra oxygen to boost power up to 30%, given the additional fuel required. This is a complicated system that might well be worth the risk, and has tempted many racers over the ages. A fire extinguisher system, with a nozzle logically placed among the intake trumpets, is ideally suited to delivering Nitrous Oxide at the touch of a button. There was once a rumour that a tubular frame car stored it in the tubes. Provided the driver can control the resulting wheelspin, he might go undetected....for a while.
· Oxygen content of fuel: There are several substances that can be added to petrol to increase the permitted oxygen content above the 3.7%m/m currently allowed. Nitromethane and Nitrobenzene are the classic substances used in racing fuels. They are worth adding if you are sure the fuel will not be tested, but, as with all oxygen additives, more fuel must be carried.
· Fuel energy content: just using a constituent of the fuel that releases more heat energy, per unit of oxygen, does not ensure that more power will be produced. Some of the high calorific substances, such as Toluene, are hard to burn and require heating (Honda introduced fuel heaters on their later turbos). The rate of burn also becomes important in a high RPM engine. However much of the intense fuel development of a few years ago, was to formulate fast burning, high energy mixes. These substances are about, and someone with the appropriate knowledge could take advantage of them.
· Fuel quantity: at Indy and Le Mans, in particular, the quantity of fuel carried in the car is limited, providing a trade off between power used (fuel consumption) and time spent in the pits refuelling. Any additional fuel that can be carried in the car, over and above the regulated quantity, is an advantage. Hidden tanks, hidden compartments in the main tank, the tubes that make up the chassis frame, fire extinguishers, all have potential for extra fuel capacity and can only be found by stripping down the car.
Many formulae dictate the level of permitted development on production engines, specifying in detail the standard components that must be fitted, and the modifications allowed. This is obviously a playing field for anyone inclined to cheat, controlled only by engine strip downs and inspections. The opportunities are too great to list and history is littered with the names of those who have been caught.
Weight. Reducing weight is the one racing car development that is guaranteed to make the car faster. From the time a minimum weight limit was introduced - for cost and safety reasons - attempts to run under-weight and yet weigh-in at the legal figure have been rife. From mechanics tucking hammers and spanners under the seat as the car is pushed to the weighing-in area, to running with empty fire extinguishers (and claiming that they went off accidentally) have all been tried. Adding fluids to the car during the last pit stop (water for "brake cooling" was favourite) was a hole in the regulations that was quickly plugged, as have most (all?) the others. The detailed regulations and weighing procedures in Formula 1 are the response to the concerted efforts to run lighter than permitted whenever it is possible.
Aerodynamics. The designers of racing cars have three main requirements from the aerodynamic systems:
1. As much downforce as possible in slow and medium speed corners, without stability problems due to pitch sensitivity.
2. As much downforce as possible in high speed corners, again without stability problems due to pitch sensitivity, but without so much drag that the car has insufficient power to maintain the speed through the corner.
3. As little drag on the straights as possible.
Up until 1977, prior to ground effect, virtually all the downforce was derived from wings which have predictable Lift/Drag characteristics. It was entirely logical to alter the incidence of these devices to optimise for downforce in corners, and drag on the straights. Once the various systems to alter the incidence were banned in 1969, every possibility of enabling the wings to flex to a lower drag configuration as the loads increased with speed, were explored. The regulation writers struggled with terms such as "degree of freedom", and wings continued to lose incidence and uncamber, and rubber mounting bushes ("just to isolate the engine vibration....") deflect advantageously. It was not until the advent of CFRP wings, and the ability to mount them rigidly to the structure of the car, that scrutineers were able to lay down the law and insist on really stiff assemblies. But there is no such thing as an infinitely stiff structure in engineering.......
Ground effect, and the regulations to limit it's influence, brought a whole new set of problems. The downforce generated by the underneath of the car is extremely sensitive to the shape of the bottom surface, the distance between it and the road, and the gaps at the lateral edges. The regulations have set out to control all these features:
· Shape: in formulae where the shape of the main portion of the bottom of the car is defined as flat, tight limits are put upon the actual flatness. Convexity of greater than 5 mm is out, but it can only be measured when the car is at rest. Any convex deflection under load, may provide useable downforce.
· Distance to road: active suspension enabled the distance to the road surface to be minimised at low speeds and to compensate for the tyre and suspension deflection with speed, to prevent bottoming out. Any means, such as asymmetric bump-rebound damper characteristics, might provide some means of achieving similar characteristics, and all spring damper systems are inspected very carefully for their ability to control ride height.
· Edge gap: the benefit of skirts to seal the edges of the car are well known, and any reduction in the gap is useful in increasing the downforce. Structural stiffness is again the key here, and explains why designers can sometimes be seen testing the stiffness of competitors' undertrays and front wing tips with their toes while looking nonchalantly the other way. Only in Indycars has a stiffness test been stipulated, with points on the edge of the undertray designated for load-deflection tests. In Formula 1 a load deflection test is only applied, most often to the leading edge of the undertray, when a competitor tries to push acceptability too far, and does not respond to admonishment.
Dimensional infringements of the aerodynamic regulations have sometimes caused a competitor to be disqualified, but this is seldom intentional cheating - the benefits of 5-10 mm error being too small in most cases - but rather a lack of checking or some structural failure. That is except in NASCAR racing.
The racing is so close and the speeds so high, that tiny changes to the profile of the saloon bodies can make all the difference. Checking is carried out using profile templates, which is notoriously difficult, and every radius must be checked because at some time in the past they have been modified. The most infamous case was a 7/8 scale version of the standard car, with every detail of the bodyshell scaled. Just big enough to avoid visual detection for a while, the frontal area and drag were down by 12.5%.
Tyres. Size and compound are what matter most with tyres, and are the two characteristics regulated - Rallying excepted, where tread pattern is also controlled. In single tyre formulae, the tyre supplier takes on much of the responsibility for seeing that all competitors are legal. It is not easy to get away with cheating by fitting oversize tyres, but compounds are hard to police. In Formula 1 compounds are not regulated, but the number of tyres for Practice, Qualifying and Race is limited to 28 tyres, any compound. Goodyear supply a race compound and a contingency (harder) compound at each event. It has been rumoured that teams have substituted tyres of a softer compound, supplied for testing at different circuits, for use in Qualifying. While not actually illegal, I suspect it would be Goodyear who handed out their own penalties, if they caught someone at it.
Some modification of the compound can be achieved by chemically treating the tread area. A very risky process, but leaving the tread wrapped in a brake fluid soaked cloth for just the right length of time, used to be one favourite.
All the foregoing involve hardware with physical properties that can be measured, one way or another - fuel specification probably being the most difficult to check. To avoid detection, cheaters must ensure that their illegal device is either not on the car when checked, or so well hidden that it is not found. The advent of control systems and the sensors, computers and actuators that make them up, elevated the potential for cheating to new heights.
Driver Aids. It is not illegal, in Formula 1, to sense anything nor to compute or store the result. It is illegal to control an actuator that governs the functioning of some system that has conventionally been under the sole control of the driver, with four exceptions: modulation of engine power, gear selection, differential internal friction and power-assisted steering. These four systems have actuators, but the way they are used is tightly controlled by the regulations, and the level of driver assistance severely limited.
Because the way in which the actuators work is controlled by software, either burnt into a memory chip or downloaded into volatile memory, to inspect the legal functioning of such devices has proved to be the hardest challenge facing scrutineers. Good software writers have the same skills as good hackers. It was inevitable that the nearly invisible world of microchips would turn into an intellectual battlefield until new boundaries were drawn and respected. Only a few experts on either side know what actually goes on.
To cheat, and not be caught at it, requires software that is either so well disguised that it's true function is not detectable, or software that is no longer resident or readable when inspection takes place. It is no longer permissible to execute code from volatile RAM, unless the team concerned can demonstrate clearly, via source code inspection, that it can only be a direct copy of code from non-volatile memory, otherwise it must be in some form of ROM that remains readable on powering down.
If the regulations are being broken, by an as yet unknown technique within software, it is likely that it sets out to achieve one or more of the following:
· Power modulation: throttle, ignition timing and cutting, fuelling, and valve timing and lift are all able to modulate the power output of the engine. To do so in response to rear wheel slip is traction control. Substantial modulation by any system other than the throttle is likely to be detectable by ear, or sensitive sound analysis. The throttle sounds just as if the driver is controlling the engine, and the only way to detect traction control via a drive-by-wire throttle is to inspect the software, looking for some sign of rear wheel or engine speed feedback. (In a given gear the engine speed is directly proportional to mean rear wheel speed).
· Gear selection: the drivers have experienced fully automatic up and down gear selection, and they like it for the freedom to concentrate on controlling the car under braking and into a corner. Now, the only function permitted is the de-selection of one gear, and selection of the next, cutting the engine or blipping the throttle and controlling the clutch during the process. Overrev. protection is permitted, for it's cost saving benefits, but if the gear selection is rejected for this reason the driver must re-select - the system must not do it for him. No form of clutch-induced traction control is permitted, especially not during a start. These provisions are hard to define and check, and the temptation to give the driver a helping hand is great.
· Differentials: controlled differentials are permitted provided they emulate mechanical ones. This development will require a whole new set of checks, as the opportunities for some form of traction control and/or vehicle yaw control are available and sought after.
· Power steering: in theory a power steering system has the potential to take away control of steering from the driver. In practice the driver would probably be the first to complain if this were to be tried. The temptation to cheat with this system is not very great.
Someone will always think up a new way of cheating the regulations, and get away with it until the scrutineers catch up. The increased professionalism of technical inspectors and the sophistication of their inspection equipment means that the opportunities are getting fewer and fewer. At the same time the penalties for getting caught are swingeing, and are beginning to outweigh the potential gains.
Until recently detection often depended on one competitor protesting the unusual performance of another. The Achilles' heel of many cheaters turned out to be the temptation to go too far, until the performance advantage was obvious.
The only time left for those who are hooked on cheating is during testing. Fast times set during the winter season may impress potential sponsors and might even panic competitors, however the only people really fooled are the cheaters themselves.