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Wednesday, October 10, 2012

Renault Sport on engine requirements for the Korean GP track


Preview to the Korean Grand Prix
Courtesy Renault Sport F1

Coming just one week after the Japanese Grand Prix, the Korean Grand Prix this weekend forms the second leg of a Far East double header. The third edition of the event will be held at the 5.615km Korean International Circuit situated on the edge of the Yellow Sea to the south-west of South Korea in the South Jeolla province, approximately 400km from Seoul.
The circuit was designed by Hermann Tilke and is part permanent road course, part street circuit, although the city that will use the streets is yet to be built! The circuit is a typical modern style track, with long straights and tight corners coupled with large run off areas, but it remains challenging for drivers and teams. The circuit is slippery and weather conditions are notoriously changeable, which when combined, often produce spectacular racing.

Korean Grand Prix facts and figures

The Korean track is another circuit of two halves; the first part featuring straights that place an emphasis on good top end power and acceleration, and the second part more flowing, with a sequence of corners that interconnect without any real straight. This combination of straights and corners puts Korea in the middle of the power-driveability ratio and mid-table for power sensitivity, similar to the Nürburgring and Malaysia.
There are three straights on the Korean track, although the longest is not the pit straight. That honour instead goes to the straight between turns two and three, which is 1,150m. Over this stretch the engine will be working at full throttle for approximately 15s. The start-finish line is approximately 700m while the burst between turns three and four is 560m. Over eighty percent of sector one is thus taken at full throttle.
With such an emphasis placed on top speed and acceleration, getting correct gear ratio selection is a labour of love, particularly for seventh gear. Get it wrong and you will either be at the limiter for too long and compromise acceleration, or potentially a sitting duck as the other cars sail past. The choice of ratios is complicated by the changeable weather conditions caused by the circuit’s proximity to the sea and low altitude, with wind direction often varying from day to day.
It is feasible for drivers to take the complex from turns six to nine at full throttle, meaning a further 700m flat out. Weather conditions, car set-up and grip levels will greatly affect this possibility, however, and potentially compromise traction through the slower corners through the remainder of the circuit.
From turn nine onwards the circuit is a combination of second, third and fourth gear corners taken at an average of 215kph. The point-squirt nature of this section means that fuel consumption is very high over one lap.

Vitaly Petrov, Caterham F1 Team

Korea is still a relatively new track on the calendar but of the recent additions it’s one of the more challenging. After the left hand turns one and two you’re onto the first long straight with a tight braking zone at the end and then another long straight, after that the second sector is much more flowing before the final part of the lap becomes a bit stop-start. We need everything from the engine in Korea — good top speed, correct gear ratios to make sure we don’t lose too much time under acceleration, plus good response and not too many ‘peaks’ for the more smooth corners. Of course a good KERS system also helps to get past and defend from other cars on one of the longest straights of the year.

Rémi Taffin, Renault Sport F1 head of track operations

The Japanese and Korean Grands Prix are geographically and temporally close and there are also some similar characteristics between the two as well. Like Japan, Korea places an emphasis on outright top speed and acceleration, particularly through the first sector of the track. There are three long straights in this sector and we’ll work on providing good top speed and acceleration through correct gear ratios, particularly in seventh. Although more or less 80% of this sector is spent at full throttle, in terms of the demands it puts on the engine, it isn’t massively demanding on the engine as the cooling and lubricant systems are not under lateral pressure.
The second sector is however where we need to deliver effective engine braking, traction and torque. There are some fast flowing turns, particularly in the earlier part of the sector, that load the engine as the driver rapidly switches direction. It’s not dissimilar to Suzuka in this respect, particularly turns six to nine that have similar characteristics to the Esses.
The final sector is a bit stop start with short bursts of acceleration between right-angled turns, which greatly increases the fuel consumption over one lap. It’s almost like three different tracks in one, so the challenge is to get the engine correctly configured for all three sectors without compromising too much in any one area.
With the championship in such a crucial stage we are really looking forward to this event. Plus, after Sebastian’s pole position in Japan took Renault’s tally of F1 poles to 199, we will be looking to secure our 200th pole in Korea, another milestone for us.