While the Power Unit itself may be seen as the most fundamental challenge of the new regulations, the resulting influence this has on the remaining elements of a car has required a comprehensive redesign of every system affected by the Power Unit.
The gearbox requires an all-new design, with eight forward gears and one reverse. Where previously gear ratios could be optimised at each race weekend to suit the particular demands of a circuit, a single ratio choice must now be nominated before the start of each season. While the broader torque band of the turbocharged V6 configuration makes this less of an issue, it is still crucial to get this right if the driver is to maximise corner speed and eventual top speed down the straights.
The main concern however is endurance, with the gearbox itself required to last for six events (compared to five in 2013). This includes the ratios, which previously could be changed for every event. While crankshaft speed has dropped, along with the number of cylinders subjecting loads onto the crankshaft, input into the crankshaft is fundamentally different; with large quantities of torque and different oscillations. Producing a reliable unit which can deliver power efficiently from the Power Unit to the road will be of great importance.
Stopping power is another area under increased scrutiny. To compensate for the additional power generated under braking through the MGU-K, teams are now permitted to use an electronically controlled brake-by-wire system at the rear of the car, managed by the ECU. However, with far less braking done through the rear wheels due to the increased quantity of kinetic energy being recovered from the rear axle, a conventional balance adjustment system would see considerable shifts in brake balance . While the brake-by-wire system is beneficial in managing such fluctuations, ensuring it works effectively is not only safety critical, but also crucial to performance in terms of allowing the driver to maximise the potential from the brakes.
Finally, weight is a key factor in performance. While the regulations stipulate a new maximum weight limit for the car of 690 kg – up from 642 kg in 2013 – this is now far more difficult to achieve. The Power Unit itself must have a minimum weight of 145 kg, while the additional cooling requirements of both the turbocharger an Hybrid systems only add to the challenge.
Fundamentally, there are two key elements to a fast Formula One car: having the most power possible to accelerate down the straight, plus good mechanical and aerodynamic performance to allow for quick cornering. The 2014 regulations bring with them a new set of challenges not only relating to the more visually obvious elements of the car, but more fundamentally in terms of packaging.
Starting with the most obvious visual change , the reduced width of the front wing – down from 1800 mm to 1650 mm – has a sizeable effect on aerodynamics, as this defines the flow of air over the entire vehicle. Moving further back, rear end grip has been directly affected by the loss of exhaust blowing; a significant source of performance over the past few years. This is a consequence of the fixed location and positioning of the single, central exit tailpipe, with the challenge now lying in how best to compensate for that loss and achieve the same levels of driveability from the car.
At the very tail of the car, a 10% reduction in the size of the top rear wing ‘box’ – down from a maximum height of 220 mm to 200 mm – will result in teams running a specification of rear wing throughout the year that would previously have been reserved for lower downforce circuits such as Spa . Removal of the lower rear wing and its direct influence on the diffuser also has an effect. The removal of one element from a previously co-dependent trio of the floor, the lower wing and upper wing results in notably different air flow at the rear of the car.
Hidden from view, but equally important, is the integration of the Power Unit and related systems into the chassis. The Power Unit itself takes a completely different shape, while more hybrid systems, a more complex exhaust system, plus the intercooler required for the pressure charging system are all contributing factors to the cooling requirements of the car. Managing heat is not only necessary in terms of car integrity, but also performance and efficiency. For example, if heat can be saved in the exhaust primaries between the engine and the turbocharger, – this can potentially be recovered through the MGU-H, leading to increased energy harvesting and an overall efficiency gain.
Two opposing influences thereby exist; one focused on ensuring that each of these components operates within an optimal temperature range, the other on packaging the related cooling systems in such a way as not to detract from the aerodynamic efficiency of the car.
PETRONAS: Technical Partner for Fluid Technology Solutions
Since the modern era of the Silver Arrows began in 2010, PETRONAS has been the team’s Fluid Technology Solutions Partner, maximising the potential of lubricant and fuel technology to provide differentiated performance. For 2014, this relationship has been significantly enhanced, with PETRONAS and the technical teams in Brackley and Brixworth working hand in hand to develop a high performance racing machine within the new parameters of the FIA regulations. If the Power Unit is the heart of the new Silver Arrow, its lifeblood is the tailor-made fuel and lubricant developed by PETRONAS’ technology.
This year, fuel energy density has become one of the controlling performance parameters for the sport and improving efficiency is now fully aligned with improving performance. In this context, lubricants and fuels have a crucial role to play in a number of different ways.
PETRONAS technologists have applied their expertise – honed through optimising PETRONAS Syntium for turbocharged, direct fuel injection engines in everyday cars – to design and co-develop new lubricants to meet the new challenges posed by the Power Unit.
A key challenge is the down-sizing of the Internal Combustion Engine (ICE) from a V8, 2.4 litre configuration to a V6, 1.6 litre configuration. The smaller ICE and its increased power per litre mean that the new engine runs hotter. Oil thins at higher temperatures, and thus a hotter engine needs a thicker oil to stop metal components from rubbing together and failing.
However, the hotter conditions and reduced quantity of oil in the ICE (reduced from almost seven litres for the V8 to fewer than three litres for the V6) also mean that the oil must contribute more to cooling the engine. This requires thinner, faster flowing oil.
Additionally, the regulation changes restrict the quantity of fuel that can be consumed per race to 100 kg, which means that the oil needs to help conserve energy by minimising friction. Again, this requires thinner oil.
In order to meet these complex and contradicting requirements, the new engine oil for the 2014 car is a precisely balanced mixture of advanced, thinner synthetic base oils to help cooling and polymer viscosity boosters (which kick-in at higher temperatures) to thicken the oil. Friction-reducing oil components – which make it easier for metal surfaces to slide past each other – have also been used to improve overall fuel economy.
Another consideration is that the higher temperatures also make it more likely that the oil itself will stop working properly. High performance additives have been included to stop the oil from breaking down under these extreme conditions.
Energy losses in the gearbox can also have a significant impact on fuel economy. To address this, PETRONAS technologists have also produced precision gearbox lubricants for the 2014 car to ensure that energy losses in the transmission are kept to a minimum, whilst making sure that the gearbox is protected from failure.
With regard to fuel, a direct injection turbocharged ICE has special requirements in terms of fuel characteristics: for example, it is very important that the injector nozzles are not blocked by deposits that come from the fuel. On top of that, the limits set by the FIA with regard to maximum fuel allocation (100 kg) and flow rate (100 kg/hr) mean that every single component in the fuel has to contribute to performance. PETRONAS scientists have developed a new fuel for the 2014 Power Unit molecule-by-molecule, balancing characteristics such as energy density, octane number and volatility with careful consideration of the mandatory fraction of the fuel that must be of bio-origin. This poses a unique challenge in itself, as some of the best components for delivering high, smooth power are also those that likely lead to deposit build-up in injector nozzles. An extensive development programme involving chemists and engineers testing new fuels in real engines has resulted in a new generation fuel for the V6 that promises to deliver a significant gain in performance.
The contribution of PETRONAS in delivering total Fluid Technology Solutions has been essential to the delivery of the 2014 Power Unit. Never before in the history of Formula One have a Power Unit and its lifeblood been developed so closely. In meeting a challenge almost diametrically opposed to that of the V8 engine, the PETRONAS technical partnership will be an integral factor in success.