Preview to the Chinese GP
11 April 2012 — After a quick break in proceedings the FIA Formula One World Championship returns to action with the third round of the series, the Chinese Grand Prix, held at the Shanghai International Circuit on the outskirts of the country’s largest city, Shanghai. 2012 will be the ninth edition of the Chinese race, having entered the calendar in 2004.
The 5.451km track is about in the middle of the table for the stresses it puts on engines. There is one very long straight where the engine is pushed to its most severe usage, but the rest of the circuit features 16 medium to low corners meaning the engine is used at relatively lower revs for the rest of the lap.
The race is known for its unpredictability; only one driver (Lewis Hamilton) has ever won at the track more than once! Renault engines have however won twice, with Fernando Alonso sealing a win in his first championship-winning year, 2005, while Red Bull Racing-Renault secured its first-ever win in 2009 when Sebastian Vettel delivered a stunning victory. Chinese Grand Prix facts and figures
The straight between turns 13 and 14 is 1,300km, therefore giving Shanghai the longest straight on the F1 calendar. The RS27 will sit at full throttle for between 17 and 18 seconds. Combined with the 700m start finish straight and other short bursts of power, the RS27 is at full throttle for 53% of the lap, a total of about 50 seconds over the 1’33 lap.
Given the time at full throttle, gear ratios need to be are carefully calculated to give acceleration without compromising maximum speed. Short ratios favour acceleration; a longer top gear ratio permits higher maximum speed. Engineers will therefore work to create a car and engine set-up that deals with all the circumstances of qualifying and the race while aiming to optimise the overall performance.
The slowest complex on the track is the radial turn from T1 through to T4 where the track tightens on itself before opening out onto a short straight. Delivering low speed driveability through this complex can give an overall laptime gain. With the regulations outlawing the use of exhaust-blown diffusers for 2012, the corresponding loss of rear downforce places a greater emphasis on driveability, in order to help the driver better modulate the engine torque out of these slow corners. Excessive wheel-spin costs both lap-time and increases tyre wear.
Sectors one and two have a mix of corners, with tight hairpins, flowing curves, two straights and radial turns. The constant changes of direction mean correct engine mapping is extremely important to give responsiveness into and drive out of the corners. Along with the complex T1 — T4, Turns 12 and 13, the radial corner that leads onto the longest straight on the circuit, demand particular attention.
Delivering fully functional KERS will also be crucial here.
Rain is predicted for this weekend, which will add another interesting facet to preparation as fuel consumption drops in wet conditions. Wind direction can also change with another weather front, which could affect aerodynamic performance on the long straight. Although this doesn’t affect the engine operations a great deal, if the car is running into the wind, the car takes longer to reach the limiter, meaning fuel consumption is higher. This makes the fuel consumption and engine mix levels quite tricky to get right.
With the race taking place at the start of the Shanghai springtime, ambient temperatures can be quite variable, but are typically from the low teens to just over 20°C. Lower temperatures will mean a greater engine power output, but will also increase the fuel consumption per lap. Last year race day was significantly cooler than during Qualifying, with Friday night’s ratio selection and strategy review taking this into account.
The location of the Shanghai track also provides an unusual challenge. The circuit is situated in an industrial zone next to several factories, some of which produce concrete, which leads to a high concentration of dust particles in the air. As such, a special air filter — similar to the one run in Hungary to deal with the fine sand particles — is run.
The drivers’ view:
Kimi Raikkonen, Lotus F1 Team
The E20 powered by the Renault engine is looking good so far this season. Shanghai is quite similar to Albert Park and Sepang in what it requires from the car so that should be good for us. We need to have good power and top speed down the long back straight; getting the KERS and DRS working well here will provide some good overtaking opportunities. But you also need traction and engine response in the slower corners, including the first complex that turns back in on itself. I won there in 2007 and that was a good feeling as that was the year I won the World Championship, so let’s see what happens when we get out on track.
The engineers’ view:
Head of Renault Sport F1 track operations Rémi Taffin gives his thoughts on Shanghai:
China is quite unique on the calendar for engines as you have a combination of the very long back and pit straight, where the engine is put under extreme pressure, but the is also a twisty first and second sector where the demands are a lot less severe. On most circuits you would have one or the other; Monza, for instance, is very quick and requires flat out power, while Hungary concentrates on the lower levels of torque.
In Shanghai, however, you have both requirements over the course of the lap. As a result, we look to deliver good engine responsiveness into and out of the corners to carry speed into the straights, but correct gear ratios to maximise acceleration. Delivering fully functional KERS will also be crucial here as passing down the straight into T14 is one of the key overtaking opportunities.
After a busy start to the season it has been good to have a bit of breathing space and allow us to reflect on the performance of the first two races and if we needed to make any adjustments to our target plan. One of our main areas was obviously the failure on Pastor’s car in Sepang. We were very surprised, particularly since we haven’t had a failure in this area in a very long while. Initial inspection at the track showed one piston had failed. We feel this was a one-off failure, but as a preventative counter measure across all our clients, we have specifically built new engines (two per customer) for China which feature a new piston specification.