HP Engine Design Feature

Power:
A smooth or consistent delivery of power is crucial for enabling the driver to place the car continually on the edge of traction and avoid sliding or spinning out. This translates to a flat torque curve, ie a constant production of torque across the useful rev range, and therefore a linear power curve (power being equal to torque multiplied by rpm). To ensure the responsiveness of the engine (easy to accelerate/decelerate), the inertia of the rotational components such as the pistons and crankshaft should be minimised. In the ideal world, this would means manufacturing these specific components as light weight as possible, though this would have detrimental effects on low-end torque and, together with increased frictional losses, the limit on high rpm rev due to the inability to handle the increasing forces and stresses.

To maximise the production of engine torque/power, there are many engineering problems to solve. The manifold as well as the pipes of the exhaust system need to be individually tuned in length, diameter and curvature to minimise blockage and ensure that the gases to/from the cylinders do not interfere with each other. The air box above the driver's helmet must provide a constant pressure and speed of air intake regardless of outside weather conditions, at all parts of the track including tight corners. Losses of energy due to vibrations, heat loss and friction must be minimised. Complex computer modelling and simulation is carried out to constantly improve every aspect of performance. For example, specialist, computer-intensive CFD (Computational Fluid Dynamics, also used to develop the aerodynamics of the car) is used to simulate the ignition, flame propagation and gas flow inside the cylinders.

Reliability:
Although an F1 engine is designed to last only 400km before being overhauled, the punishment on the engine components over the course of a Grand Prix - from heat, g-forces and maximum rpm - far exceed that experienced by a commercial engine during its lifetime. In addition, unlike a normal consumer vehicle, the engine in an F1 car is part of the chassis structure and therefore must absorb some of the forces produced by the rear suspension. Consequently, reliability is a key concern for all engine manufacturers. At BMW, complex Finite Element Method (FEM) software is used to calculate the stresses and deformation on components. Computer simulations and measurement such as vibro-acoustic analysis and 400km tests of the Hockenheim circuit on dynamometers, controlled by HP Armada notebooks, are carried out to determine the fatigue lifetime of critical engine components. This data is fed back into the design process, ensuring each component is built to handle the stress of racing.

As factory tests are unable to fully simulate the g-forces, airflow/cooling characteristics, and track surface vibrations encountered in racing, track testing is still invaluable as a source of information when looking at reliability,. Telemetry data gathered at these tests, logged onto the HP ProLiant servers, provides important information when examined in conjunction with engine components. Comparing levels of physical wear with the data helps engineers pinpoint the weakest link components - those most likely to fail first. Another technology, two-way telemetry, is also used to maximise reliability by allowing the team to limit the engine's rev range, or even switch in the spare oil reservoir if needed. Mapping, where the engine's performance requirements for every metre of track are input to the engine management system, helps increase reliability. This procedure ensures that all engine set-up parameters are optimised, thus minimising unnecessary stresses on the engine components. When it comes to life expectancy, some components, such as cylinder heads, have a longer working life than others and are recycled for engines to be used in testing, practice and qualifying sessions - situations where the mileage requirements are reduced. For a Grand Prix all parts of the engine are brand new.

Future:
In the quest for ever more performance, it is likely that the future of engine design will be driven by developments in two areas: materials and computer simulation. Lighter, stronger and more stress/vibration tolerant materials will not only provide engineers with more design flexibility, but will continue to boost power output while improving reliability. Better and more complex computer simulations for structural, thermodynamic and gas flows analysis will also evolve and become an even more valuable part of the engineers' toolkit. The role of computer modelling and simulation in engine design today is already invaluable, as Mario Theissen (BMW Motorsport Director) describes: "Nowadays computer simulation plays an indispensable role in both the road car development as well as in our work for motor sport projects. Without the state-of-the-art computer software and hardware neither the current speed of development nor the products' quality would be reachable."

Facts & Figures:

Number of combustions during an average GP 8 million
Number of engine & vehicle measurements taken per second at top speed 150,000
Maximum rpm 19,000+
Approximate number of individual parts 5,000
Approximate number of different parts 1,000
Maximum exhaust temperature during a race (°C) 800
Number of litres of air aspirated in 1 second at top speed 450
Average number of F1 engines built in a year 200
Weight in kg (less than) 100
Number of hours to assemble 80
Hours needed to check a new cylinder head using computer tomography 20
Minimum number of complete engines brought to each GP Race 10
Tonnes of equipment transported to each GP by BMW 6