Technical preview of Shanghai with Mercedes GP
Other circuits may dispute the fact, but the Shanghai International Circuit currently boasts the longest straight in Formula One. The run from turns 13 to 14 totals 1170m - the equivalent to 11 football pitches laid end to end, or the same length as three and a half of the world's biggest aircraft carriers - and represents one of the toughest tests of the year for a Formula One engine.
This special challenge in Shanghai led the Mercedes GP team to delve into exactly what stresses and strains the engine undergoes during the lap and on that extremely long straight...
How long is the back straight in Shanghai and how does it compare to other circuits? "The back straight at Shanghai International Circuit covers 1170m, equivalent to 21.4% of the total lap distance. This is the longest straight encountered during the Formula One season, closely followed by Abu Dhabi (1140m), Monza (1120m) and Yeongam (1050m)."
What demands does this place on a F1 engine? "The engine spends a full 17 seconds at wide open throttle, which represents approximately 18% of last year's pole position time. This is the second longest period at wide open throttle of any circuit: it is exceeded only by Spa, where the run from La Source to Les Combes (including Eau Rouge) lasts for 23.5 seconds. Conversely, Monaco has the shortest: a mere 7.5 seconds."
How demanding a circuit is Shanghai for the engine overall? "In terms of the percentage of the lap spent at wide open throttle, Shanghai is actually among the least demanding circuits of the year: 62% of the lap compared to the maximum value of 83% in Monza."
What loads do the engines moving parts undergo during the lap of Shanghai? "A piston will complete over 12,000 cycles, and the crankshaft 24,000 rotations, during every lap in Shanghai: this can be translated to nearly 2km of distance travelled by the piston. Out of that, 450m are accounted for in the back straight. At peak revs, the pistons will be subjected to accelerations of 81,000m/s2. This acceleration equates to more than 8,250G and the force held by the piston exceeds 50kN - equivalent to the weight of more than three standard road cars. For the valves, life is even tougher: they experience higher accelerations, with impact pressures almost 30 times greater than those endured by the pistons during combustion."
What role do the lubricants play? "Specially formulated PETRONAS Syntium lubricants play a crucial role in blending performance and reliability. Bearings, for example, suffer critical conditions at both high and low speeds. Much of the time, lubricated surfaces are separated by gaps smaller than a micrometre - in other words, less than one thousandth of a millimetre."
How much air does the engine admit at maximum revs? "At 18,000 rpm, the engine admits around 450 litres of air per second - which would equate to 27,000 litres per minute at maximum revs. By way of comparison, a Mercedes-Benz C-Class Estate has a load capacity of 485 litres."
Source: Mercedes GP
