Marina Bay Circuit: three corners in detail
The Marina Bay circuit has 23 corners, of which 10 are taken in second or first, 7 in third and only 1 in fourth gear. Corner 3 is a good example of a ‘typical’ Singapore corner. The driver brakes down from around 290kph at the end of the pit straight, shifting down the gears before a quick blip of the throttle for turn 2. He then brakes even further, shifting down to second gear for turn 3. The speed at this point will be under 100kph and the engine will be working at around 13,000rpm, the lower end of the rev range. Engineers will work on the overrun settings to give increased rear stability under braking. They will also look at using shorter gear ratios to maximise acceleration for the short bursts of power between the corners.
Turns 5 - 7
Singapore has just two short straights: the pit straight and then the curved straight between turns five and seven, which shoots down Raffles Boulevard with its luxury hotels and boutiques. This short straight – only 700m – will see the driver engage seventh gear and touch the 300kph mark, giving the engine a chance to breathe. With the ambient temperatures generally over 30°C, even at night, it’s a welcome opportunity, particularly as after turn 7 the track goes into a series of low speed, low rev right angled corners for the remainder of the lap.
This sequence starts in Raffles Avenue, one of the city’s busiest urban thoroughfares. As a result the surface is quite bumpy and the car may become unstable, particularly under braking for turn 16, a sharp right-hander. Similar to Monaco, the drivers will try to avoid the biggest bumps, which cause the cars to lift momentarily. With no load running through the engine, the engine suddenly accelerates and hits the rev limiter, causing a loss of time and potential damage to the engine. Engineers will therefore pay particular attention to the shift light pattern and even encourage the driver to shift early to avoid hitting the rev limit too often.
Rémi Taffin, Renault Sport F1 head of track operations:
Singapore is a very different challenge to the high power tracks of Spa and Monza. Most obviously, it is a street track, winding its way round some of the city’s most famous landmarks in a series of low speed, low rev turns. In sharp contrast to Belgium and Italy, power sensitivity is amongst the lowest of the season as less than 45% of the lap is spent at full throttle and the average speed is around 170kph. The new T10, now a straight left hander instead of the sling corner, slightly increases the percentage of wide open throttle time and fuel consumption, but the nature of the Singapore track remains unchanged. This means top speed is not so important here; instead we focus on a smooth power curve in the lower rev ranges and good response out of the high number of corners. The stop-start nature of the track and the short bursts of acceleration between the turns make Singapore one of the least fuel efficient of the year so we try and be as careful as we can with the engine settings to avoid a weight penalty. To avoid finishing with too much fuel on board – and therefore a time penalty per lap – or too little fuel, drivers constantly play with the engine modes, adjusting to have more or less rich fuel mixtures. However, due to the low power sensitivity, we can use leaner engine modes to try to reduce the fuel at the start of the race, which effectively acts as ballast. Getting the correct fuel load for the start is one of the major challenges of the weekend as engineers will also have to consider the likelihood of weather changes and safety cars.
Unusually, given the local climate, we have not had a wet race in Singapore, but even without rain humidity can be well over 80%. This also plays a role in the configuration of the engine as the higher the water content in the air, the less oxygen there is available to burn so power output drops slightly. This is offset by the race taking place at close to sea level and the circuit’s relatively low power requirements, but it is nevertheless an important consideration when we look at engine maps and operating parameters.
Temperatures are also something to watch carefully – particularly as the race is the longest in duration of the year. While temperatures during the night are typically lower than during the day (between 5 and 6°C cooler), the enclosed nature of the track between the buildings keeps ambient temperature high. Cooling systems are therefore carefully monitored, particularly since the cars are going relatively slowly and often circulating closely to each other, raising the operating temperatures further. For these reasons we tend to use an engine at the end of its life.
Renault Sport F1