Gaining More Power: Fuels And Lubricants

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Given the current engine freeze enshrined in the regulations, it is still possible to find a few extra horsepower by optimising combustion and limiting friction.

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Fuels: a limited framework

The Formula 1 technical regulations are very strict. For several years now the fuel formula has been confined within a very precise framework by limiting the amount of hydrocarbons in the composition of the final product. Today, an F1 car has to run on lead-free petrol, which must meet draconian pollution restrictions. Furthermore, 5% bio fuel will be added to the mixture in 2008. There is still a tiny window for manoeuvre, though, and this is what interests the petrol companies.

The combustion process must be increasingly rapid to release the power. The petrol has to vaporize very quickly in a homogeneous fashion, and the flame spread has to be almost instantaneous. The aerodynamics of the combustion chamber, the flow from the injectors, the design of the plugs and the electronics all play their part. It is the same thing for the quality of the fuel, which is formulated on a bespoke basis for each engine. This being said combustion is not everything. Today, the idea of consumption and the density of the fuel have an important role to play. By varying the energy in a specific dose of fuel it is possible to modify race strategy. So the top grade unleaded that the RS27 V8 burns has a density close to 725kg/m3 as compared to 750kg/m3 for the fuel from a pump. The aim is to be lighter while maintaining the same performance. The final result is a specially formulated fuel made up of 200 ingredients that enable the team to gain some extra horsepower. So the V8 Renault uses unleaded premium 95 octane fuel. If it used the same fuel as a Clio it would suffer a power loss of around 5%, some 35 bhp!

Lubricants: freedom to innovate

In the face of the freeze imposed on the V8 engines by the technical regulations, the engineers try to optimise the energy unleashed during combustion by limiting internal engine friction. In this area the viscosity of the lubricants plays a decisive role. It conditions the performance of the running gear: crankshaft, con rods and pistons. The film of oil between the metal parts must be thin enough to ensure maximum slip speed. These components and the oil have to cope with enormous physical constraints. A piston, for example, goes from 0 to 37 m/s almost 600 times per second. If some parts of the engine like the middle of the ring of the piston