Circuit de Catalunya: The "complete" race circuit that frustrates the engineers

The Formula 1 engineers have a love/hate relationship with Circuit de Catalunya; it is the track they know the best from the pre-season testing that has been held there for many years, but it is an enigmatic circuit, always changing with temperature and wind conditions. A car, which flies in the morning, can be uncompetitive in the afternoon, without anything being changed on the car itself.

As the first European race of the season it is also a track where teams bring their first major technical update package to the car, which will have taken 10-12 weeks of wind tunnel development. So teams always have high expectations, which do not always come to fruition and that can add another layer of frustration.

The track has a bit of everything in terms of corner types and is a very good test of a car’s aerodynamic efficiency. The most important sector of the lap is the final one, which features low speed corners. The most lap time gain and loss is here. Performance in the final sector this weekend is often taken as an indicator of how well a car will go at the next race in Monaco.

The Pirelli medium and hard tyres will be used this year – last year it was the soft and hard. This single step between compounds should make the strategies more evenly balanced, as we shall explain. Pirelli has changed the specification of the hard tyre so it is closer to the 2012 model, while the company is also supplying an extra set of these tyres to each team for use on Friday so they can gain more mileage and knowledge.

Track characteristics

Circuit de Catalunya; 4.65 kilometres. Race distance: 66 laps = 307 kilometres, 16 corners in total, considered the best test of an F1 car’s aerodynamic efficiency due to combination of medium and high speed corners.

Aerodynamic setup – High downforce. Top speed 317km/h (with Drag Reduction System active on rear wing) - 305km/h without.

Full throttle – 60% of the lap. Total fuel needed for race distance: 154kg (quite high). Fuel consumption: 2.34 kg per lap.

Time spent braking: 12% of the lap (quite low). 8 braking zones. Brake wear: Medium/low.

Total time needed for pit stop: 19.8 seconds.

Fuel effect (cost in lap time per 10kg of fuel carried): 0.40 seconds (high)

Form Guide

The Spanish Grand Prix is the fifth round of the 2013 FIA F1 World Championship.

Qualifying has historically been critical in Barcelona; the last 12 races on this track have been won from pole position. The arrival of DRS rear wings has meant a significant improvement in overtaking, which was always a problem at this circuit.

The form guide so far shows two poles and two wins for Red Bull Racing, a win and three podiums for Lotus, with two poles and two podiums for Mercedes and a win and a podium for Ferrari

Barcelona is likely to see many teams bring through some major car developments; front and rear wings, floors and improvements around the exhaust area. A good Barcelona update should be worth around three to four tenths of a second per lap.

As far as drivers’ form is concerned at Barcelona, Felipe Massa, Jenson Button, Pastor Maldonado, Kimi Raikkonen, Fernando Alonso, Sebastian Vettel and Mark Webber are all previous winners. Lewis Hamilton has never won the event.

Weather Forecast

The long range forecast looks good with temperatures around 20 degrees and a low chance of rain.

The wind is often a significant factor at this track, sudden gusts and crosswinds can upset the balance of the cars, particularly in the final sector.

Likely tyre performance and other considerations

Pirelli tyre choice for Spain: Hard and Medium.

Catalunya is a tough track on tyres, with the long Turn 3 the most difficult corner. It is taken at 240km/h and the corner lasts for four seconds, which puts a heavy load on the left front tyre. The surface is also quite abrasive.

Last year Pirelli brought the hard and soft tyre while this year they have brought hard and medium. The Hard tyre has been changed after the first four races of the season and is now similar to the 2012 hard tyre, which was the preferred race tyre in Spain last year. The predicted temperatures for the weekend should mean that the hard is in its ideal operating window.

The difference between the medium and the hard should be around 0.5s to 0.8s per lap.

Friday practice will be vital in establishing how long a set of each compound of tyres will last in the long runs in particular. This will dictate qualifying strategy, with teams looking to preserve new sets of their preferred race tyres.

With some high energy right hand corners, the limitation will be with the tyres on the left side of the car, particularly the front; when their performance starts to drop off it will be time to pit.

Number and likely timing of pit stops

With essentially the same hard tyre as last year and the 2013 medium tyre, it is likely that we will see a mixture of two and three stop strategies.

To make a two-stop work a team needs to be able to get to lap 14 or 15, while a three stopper will come in for the first time around lap 10.

Three stops is likely to be the preferred route, with stops on roughly laps 10, 26 and 44.

Chance of a safety car

There have been 5 Safety Car periods in this race since 2003, and 4 of those were for first lap incidents.

Recent start performance

At 730 metres, the run from the grid to the first corner at Barcelona is the longest of the season. So a fully functioning KERS is vital.

Starts are crucial in race strategy and can make or compromise a race.

As far as 2013 start performance is concerned drivers have gained (+) or lost (-) places off the start line this season, on aggregate, as follows –

Gained


+9 Van der Garde

+7 Perez


+6 Button


+6 Gutierrez


+5 Maldonado



+4 Alonso



+4 Sutil***



+4 Hulkenberg**



+2 Chilton

+2 Bianchi


+1 Pic



Held position



Vettel


Di Resta

Lost


-1 Bottas

-1 Massa


-2 Rosberg


-2 Webber*


-3 Hamilton


-3 Raikkonen


-4 Ricciardo



-5 Grosjean


-7 Vergne ****


*Webber dropped from second to seventh after a clutch problem in Australia
** Hulkenberg did not start in Australia *** Sutil suffered puncture from contact with Massa in Bahrain ****Vergne retired following collision.

Pit Stop League Table

Of course good strategy planning also requires good pit stop execution by the mechanics and we have seen tyre stops carried out in two seconds by F1 teams.

The league table below shows the order of the pit crews based on their fastest time in the Bahrain Grand Prix, from the car entering the pit lane to leaving it.

Worth noting is how close it has become with just over a tenth of a second separating the top four teams and 1.5s separating the whole field.

1. Red Bull 21.031s

2. Ferrari 21.123s


3. McLaren 21.161s

4. Mercedes 21.183s 


5. Lotus 21.556s

6 Sauber 21.656s

7. Toro Rosso 22.028s

8. Force India 22.099s

9. Williams 22.066s

10. Caterham 22.252s

11. Marussia 22.552s

The UBS Race Strategy Briefing is written by James Allen with input and data from several of the leading teams' strategy engineers and from Pirelli as well as JA on F1 technical adviser Mark Gillan