China Preview: The secrets of DRS set-up

On paper, it seems simple enough. Get within a second of your prey, press a button and the DRS rear wing opens. Drag is slashed, top speed is boosted and before you know it you're overtaking move is complete. But like everything in Formula 1, it's not anything like as simple as that.

Even the relatively humble DRS system creates a whole series of setup questions that teams must grapple with each and every grand prix weekend.

Central to the challenge are the different ways that the DRS is used, primarily the fact that its deployment is unregulated during qualifying but strictly limited in the race itself. As Force India technical director Andrew Green reveals, there are a series of compromises to be made that can depend on where exactly you are likely to be on the grid.

"Whether you are at the front of the grid versus being the in the midfield, if you are attacking or trying to defend, makes a big difference," explains Green. "For us, the big compromise is in the drag and downforce level of the car. There is a conflict between qualifying aero setup and race aero setup.

"If you optimise your aero for qualifying, then you are going to be running too much wing in the race. But if you optimise it for the race, then you haven't got enough wing for qualifying. That's the balance that we are trying to strike. We have always taken the view that the action happens on Sunday and we will set the car up for most circuits - Monaco is probably the exception - for the race. Some other teams look at it differently."

The overall downforce level is just one part of the equation. On the Friday night of each grand prix weekend, teams must finalise the gear ratios they intend to run for the rest of the event. These are selected from a pool of ratios that are declared before the start of the season, as a cost saving measure.

"Once you have decided on the downforce level, the gear ratios come in second," says Green. "Do you want to go for ultimate top speed and longer ratios, or acceleration off the corners and shorter ratios? That decision is circuit-dependent and you will see different ideas up and down the pit-lane.

"But it comes down to where you want to be quick - Saturday or Sunday.

"It can be tough because deciding calls that reduces qualifying pace are hard to make and difficult to accept. But on Sunday that decision will be justified. Let's say that it sparks a lot of debate though!"

By and large, Force India's focus on the race means that its gear ratios are set to hit 18,000rpm without the DRS being deployed. That means that the DRS is not so much about an increase in top speed.

"Yes," says Green of whether the team gears for 18,000rpm without the DRS. "It can just be about hitting maximum revs for a longer time. So you get out of the corner quicker, you accelerate quickly and pull away from the guy who is trying to pass you.

"By the time he deploys his DRS and catches you, you are already at the braking zone. He has the higher top speed, but you get to your top speed far quicker."

But it's not just about gear ratios and wing angles. There are second order influences to be taken into consideration. Open the DRS and your overall downforce level drops, which means that the ride height, calculated based on overall downforce, will increase.

"That's another area of the DRS that's also a compromise," says Green. "With the DRS activated down the straight during qualifying, you run a bit higher. You could, in theory, start to lower the car in qualifying trim but then you pay for it in race trim.

"You have to be mindful of the ride height difference as well, and the energy that goes into the tyre. Whenever we do simulations on Friday and Saturday, it will be without using DRS to give us the best data for Sunday in respect of tyre energy, ride heights, plank wear. It does affect all of that as well. We could run the car lower if we wanted to focus completely on qualifying."

Green estimates that setting up the car purely for qualifying rather than the race would be worth a good few tenths of a second, and far more than that at a track like Monza. But clearly it would be a foolhardy thing to do as the race has to be the focus.

Nonetheless, this is one factor that could make a difference between a team's place in the competitive order in qualifying versus the race, even though no team would be foolish enough to focus completely on Saturday. Ultimately, it's a question of compromise, compromise, compromise.

"There are reasonable compromises to be made at most tracks," continues Green. "Monaco would be at one end of the spectrum. With the DRS zone in the tunnel being removed, there's very little compromise between race and qualifying setup. Then it steps up through the tracks like Hungary all the way to the high speed circuits where it makes a big difference, like Monza.

"We discuss it at lengths in strategy meetings. When you are in the midfield and it's so tight, there are some tricky decisions to be made."

Usually teams will have a very clear idea of their approach to the areas of setup related to the DRS heading to a race courtesy of advanced simulation techniques. Come Friday practice, it will be a questions of fine-tuning, perhaps if wind conditions aren't quite right, and it's rare to have to make a wholesale change. Even though the FIA notifications of the DRS zone(s) to be used in the race often come to the teams less than a week before the race, its precise location in the race isn't a major factor in the setup philosophy.

"For us, the DRS zone is almost secondary," says Green. "We know we are going to get a DRS zone, we just can't be sure where exactly it is and how long it is. We spend 90% of our race without DRS and what we are comparing is qualifying with DRS to racing without it. So the fact that we don't get the DRS zone until a few days before the event doesn't actually affect us that much.

"We will have a quick look at the simulations to make sure we aren't having ourselves over with funny gear ratios at that point, but it's about qualifying versus race. We take the DRS in the race as a bonus when we get it we'll take it. Our strategy for defending stays the same."

Strategy

Tyre degradation should be less of an issue than was feared in Malaysia, but as Lewis Hamilton's 2011 triumph proved, a three-stop strategy might still be more effective given the effect of long straights and even longer winding corners.

Those long straights also play into the hands of the DRS, and if last year was any sort of guide overtaking could prove plentiful. The wildcard, as was the case in Malaysia, is the weather. The threat of rain means switching the tyres on, rather than preserving them, could be fundamental.

Weather

Key Stats

• Sebastian Vettel has started his last three Chinese Grands Prix from pole, but has won only once, in 2009. He was sixth two years ago and finished second last year, passed a few laps from the end by Lewis Hamilton.

• Mark Webber has missed out on the top 10 in qualifying in half of the races he has contested in China. Last year he only qualified 18th, but managed to fight his way through to third - the only driver in the history of the Chinese Grand Prix to have posted a podium from so far down the grid. To put this into perspective, no-one else has scored a podium in China from 10th on the grid or lower.

• Lewis Hamilton is the only driver to have won the Chinese Grand Prix twice (in 2008 and 2011). He has also scored two poles (2007 and 2008) and two fastest laps (again in 2008 and 2010). He has always qualified in the top 10, and missed the points only once - in 2007, when he retired in the gravel trap.

• Last year the Briton secured victory courtesy of a late pass on Sebastian Vettel on the fast Turn 7. It was one of only three passes Vettel suffered all year.

• Nico Rosberg led both in 2010 and last year (a third of the six races he has led in his F1 career), but he has only once climbed the podium when he finished third in 2010. While he has always finished in China, he has only scored points in the last two years.

• Kimi Raikkonen won in China in 2007, and scored points three other times (2004, 2005 and 2008). His qualifying performances are also noteworthy: 6-0 against his team-mates, and he has never started lower than eighth.

• Pedro de la Rosa finished fifth for McLaren in 2006.

• All the current world champions have won in China, with five of them coming from five different grid spots: Vettel from pole (2009), Raikkonen from second (2007), Hamilton from third (2011), Button from fifth (2010) and Schumacher from sixth (2006). Alonso won from pole in 2005 and is the only one who has led an entire Chinese Grand Prix.

• McLaren and Ferrari share the record number of wins in Shanghai. McLaren is also the only team to have always scored points in China.

• Ferrari meanwhile might have three wins, but it last climbed the podium in 2008 - also the last time it managed to reach the front row in qualifying.

• Force India is yet to score a point here, even in its former incarnations as Spyker, Midland and Jordan. Its best qualifying effort was Paul di Resta's eighth last year.

• It will be interesting to see if Sauber is able to maintain their recent form in China, as it has only scored points in the last three years - when Kamui Kobayashi finished 10th last season. The team's last top-10 grid appearance was back in 2008.

Famous Five

2011
There may not be a dearth of races to choose from - Shanghai having hosted just eight grands prix - but 2011 is an obvious standout as Lewis Hamilton halted Sebastian Vettel's runs of victories with an incredible late charge.

The McLaren driver's three-stop strategy proved a better bet than Vettel's two, allowing Hamilton to hunt down the German and pass him in the final laps as Vettel struggled with tyre wear. Hamilton's victory also gave him the circuit record - no other driver has won more than once at Shanghai.

In what was seen as a victory for both DRS and the new Pirelli compounds, the race featured plenty of action, not least from Mark Webber, who charged from 18th on the grid to finish third.

2010
There were plenty of headline developments over the 2009/10 pre-season, but few were more dramatic than Jenson Button's switch from Brawn to McLaren - decidedly Hamilton territory. Few thought the reigning champion would be able to hold a candle to his younger team-mate, only for Button to blast to victory in the inclement weather of Australia.

While that didn't silence the doubters, his second victory in three races did. Button later labelled his 2010 Chinese victory as his "best victory in Formula 1 - an extremely special win in very tough conditions." They were indeed very tough conditions, as rain played havoc with the field. Amid frantic pitstops and falling rain Button kept his head and opted to stay out on slicks as most of the field pitted for intermediates - a call that proved to be right and earned him a healthy lead. Even when a safety car eradicated that advantage he kept calm and was able to stretch away from Hamilton in the closing stages. Any lingering doubts about his ability were duly revised.

2009
The 2009 Chinese Grand Prix wasn't in isolation the greatest race staged on the Shanghai straights, but it did have significance as Vettel gave Red Bull its first F1 victory, leading Webber home in a commanding one-two.

Brawn and Button had proved the dominant combination in the opening two races, but it was Vettel who qualified on pole in China, ahead of Fernando Alonso's Renault and his Red Bull stable-mate Webber. The race began with eight laps under the safety car due to the extreme wet conditions, which was bad news for Alonso: his minimal fuel strategy was ruined, and at the restart he dived in immediately for fuel, allowing Vettel and Webber to run one-two.

The pair gradually eased away, and while Button was able to split them during the stops, he could do nothing about their overall pace. When Vettel pitted for the third and final time he came out on Button's tail, virtually assuring him of victory. He then made sure of it by passing the Briton at the hairpin on lap 40. When Button pitted, Vettel and Webber were free to stroll home.

2006
Michael Schumacher set up a grandstand finish to the 2006 championship by taking victory in China, with two races still to run. The German delivered a virtuoso drive in changeable conditions, with victory moving him level on points with Alonso and onto the fringe of a record eighth world championship crown.

The ambition would of course never quite be realised, and Schumacher's Chinese win remains - to this day at least - his last F1 victory. But the manner of his win - overshadowing Alonso, who led for 30 laps but then struggled with tyre issues - was a stirring and dramatic performance by one of sport's greats.

He had started from sixth, and by lap 10 was already more than 20s down on Alonso. Schumacher had soon passed the Hondas of Rubens Barrichello and Button however, but as a dry line began to form he closed quickly, moving into third and closing on Giancarlo Fisichella - who in turn was closing on his own team-mate Alonso. Shortly after the Italian moved into the lead, Schumacher picked off Alonso and, when the leaders made their final stops, swept by Fisichella to capture a lead he would never surrender.

2004
Rubens Barrichello has the honour of taking victory in the inaugural Chinese Grand Prix back in 2004, claiming what was his second successive win of the year to guarantee himself second spot in the world championship.

Having played second fiddle to his more illustrious stable-mate throughout the year, Barrichello started on pole and was rarely looked threatened as he used a three-stop strategy to control the race from the front. Schumacher meanwhile finished in an unfamiliar 12th, having started from the pitlane and suffering both a spin and a puncture as he tried to fight back.

In his absence Button and Kimi Raikkonen carried the fight to the Brazilian, although his winning margin of just over 1s was deceptive as Barrichello wound down in the final laps. Button's podium would help him finish third in the world championship, and help his BAR team edge out Renault for second in the constructors' fight.

From the forum

If there are any protests / disagreements, please sort this mess before Australia. It does not look nice when you start a new season under the cloud. FIA should change their procedures, I don't care what they decide on and whom they 'favour', just be done with this nonsense before season starts and let them compete throughout without further intervention.
Primer

The first two races have shown us that McLaren are the team to beat albeit, in race conditions, Red Bull are very close to them. Below those two teams it is still very hard to draw any firm conclusions with the first two races having been somewhat 'messy' and with Mercedes being so much less competitive than they have been during qualifying. In 2011 we saw some teams adopt two-stop strategies but the three-stopper proved to be superior and with this year's tyres being softer, I think that is likely to be the case again.
Dunder

An interesting thing Ross Brawn said about the Merc was that Rosberg came into the pits in Malaysia saying his tyres were finished, yet when they inspected them they found them to be in fine condition. He said that the car seems to just switch its tyres on/off and that it lurches between these two states, and Rosberg mistakenly thought his loss of grip was down to the rubber being finished. So in other words, they might have sorted out their tyre wear issue, but it's now down to how they 'use' the tyre that they're still trying to figure out. It shouldn't be a surprise, this car is the great grandson of the BGP001 which was very sensitive with its tyres. These traits often remain with teams for many years despite the different cars.
PretentiousBread

*Key stats supplied by FORIX collaborator Michele Merlino.

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