By Craig Scarborough, England
Autosport-Atlas Technical Writer
Fresh from the summer break, the teams were faced with the challenge of running on a brand new circuit, which tested the cars' setup, the tyres' endurance, and the drivers' patience. Craig Scarborough looks at the technical problems and solutions seen at Istanbul
As the teams came back from their summer holiday, the Grand Prix circus recommenced at the new Turkish circuit near Istanbul. This meant the teams had to understand the track's layout and use what little data is available to establish a base setup for the cars.
While the track eventually presented a truly challenging layout, with inspiration taken from a range of current circuits, the teams appeared to have been conservative with the solutions they brought to turkey. There were no truly new solutions and only variations on existing designs were introduced.
The reticence to bring new parts to a new track is understandable, but the track's challenging layout likens it to several of the forthcoming circuits, so if ever there were a good place to bring developments, Turkey would have proven to be it.
The Istanbul Otodrom
Designed by the most popular circuit designer, Herman Tilke devised the Otodrom's layout using Bernie Ecclestone's input and making the most of the hills forming the bowl that the circuit sits within. Tilke maintains a few fixed ideas about what constitutes a good circuit - a wide track and long straights, preceded and ending in slow corner complexes.
With this layout, Tilke would expect a car to be able to follow the leading car closely through the slow preceding corner, unperturbed by aero influences of faster corners, then make a slipstreaming pass along the straight or late braking into the next slow corner.
This theory works well in practice, but some of his recent circuits have lacked any daring corners around the balance of the lap, making the circuit dull and uninteresting. For Istanbul, however, Tilke added the now-infamous Turn 8. This turn is actually made up of four apexes, leading onto a small straight. The entry is banked and approached under braking, the corner turns left and the outside kerbs close in on the tightening bend. The tarmac run-off at that point was tested in every session and throughout the race last weekend.
This corner sees the car laterally loaded with 4g for over seven seconds, making this the heaviest loaded corner in F1. But the drivers' ability to take this corner fast was compromised by bumps on the racing line all the way round the first half of the corner. Most of the apparent errors in qualifying were usually preceded by the car bottoming more than expected from the heavy fuel and high aerodynamic loadings.
Photos of the cars going into the first pair of apexes show the stiff cars rolling and flexing their tyres. This extreme deformation of the tyres must have worried the tyre manufacturers, but only Williams experienced problems and (as yet) these have not been linked directly to the loads through Turn 8.
Following on from Turn 8 is a tricky chicane approached downhill at great speed - and the combination of downhill approach and heavy braking did upset quite a few cars' composures, as the weight shifts forward from both the braking and gradient, unloading the rear tyres and inducing oversteer. This layout did allow for some overtaking moves in the race.
The teams were expecting the temperatures to be much higher than the weekend proved. Furthermore, there was a lot more grip than expected from a virgin race circuit. This messed up the tyre suppliers' predictions, and the teams were caught between hard and soft compounds.
As a result many teams ran with compromised tyres and had to adapt setup and strategy accordingly. Most teams still opted for harder tyres in the correct expectation that Sunday would be warmer - the track temperature before the start of the race proved to be 46 degrees.
This change from qualifying also lead to some teams altering the car's setup in the opening pitstop. Since the hotter track improved the front tyres' grip while stressing the rear tyres, the cars suffered from oversteer. Therefore, the teams opted for a bit less front wing flap angle, in order to make the oversteering cars less neutral.
Race strategy was almost universally two stops, the fast laptime and long pitlane making for fewer stops, despite the extra weight affecting brake and tyre and compromising speed up the gradients. Jordan ran a three-stop race, while Takuma Sato, who had a grid penalty, pitted at the race's start and effectively ran a one-stop race.
Learning the new circuit
The process of getting an almost perfectly setup car in the garage for Friday practice started many month ago, starting with the FIA's official maps of the circuit. These are put into the teams' simulation programmes and compared to existing corners around the existing circuits, to gather comparative data.
From there, the teams alter the usual setup parameters of weight, suspension and aero to find the best compromise for the circuit. After many iterations, the teams will have a base setup and a choice of option to develop the car's handling over the opening days.
While not perfect, this approach will see the teams close enough not to change gear ratios or wing sets over the weekend, and instead they concentrate on the usual tweaking to match the car to the prevailing grip levels and drivers' individual styles.
<Team by Team
Minute changes were present on the Ferrari. The winglet brake ducts (circled yellow) were evolved with larger inlets, belying the belief that they had no real cooling function and only an aerodynamic one.
Michael Schumacher ran a new Schuberth helmet, using a clip on the chin bar to snap the visor in the closed position. More usually this is completed by the simple use of a hole on one side of the visor located on a pin on the helmet. The downside to this setup is that only the hand on the side of the hole/pin can be used to open the visor, so perhaps Schumacher's centre clip allows him to open the shield at pitstops with either hand.
Recent races have seen a whole host of debate about Schumacher's wing mirrors and the mirrored lollipop used at pitstops. The wing mirrors are simply re-sited to allow the World Champion to view his rear tyres during the race and make better judgment on how to preserve them.
But mirrors are not solely designed to be aerodynamically neutral, instead they do have a positive influence on the flow over the join between sidepod and engine cover. Indeed, the small inboard section of sidepod they are often attached to is a separate piece of bodywork to allow changes to the leading edges' shape. Schumacher, however, has requested that Ferrari forego the small aero benefit of the usual crank-mounted mirrors and instead have slightly less efficient upright versions.
Equally, the mirror on the lollipop is to allow the driver to anticipate the refueller's pulling the nozzle out, rather than simply wait for the lollipop to be lifted.
A lack of grip blighted the team's Friday preparations, and while other teams struggled, Ferrari seem to be worse off on their Bridgestone tyres. Exacerbating this problem was the improved tyre construction used at the past two races, which wasn't chosen for Turkey. With the softer tyre suffering from excessive wear, the harder compound was chosen, which compromised their grip and pace. Subsequently, both drivers had spins during the course of the first two sessions.
Rubens Barrichello qualified with a clean lap but simply lacked pace on his heavy fuel load. Schumacher had a less accurate lap than his teammate, and going into Turn 9 the car appeared to be well balanced but the rear swung around, sending the German into a spin and forcing him to abort his lap.
Overnight, the team opted to change Schumacher's engine, which leaves him a fresh engine for Spa-Francorchamps.
A good pair of Friday sessions underlined BAR's improved form of late, Jenson Button setting the fifth fastest time. Takuma Sato's qualifying lap was going well until the car grounded going into Turn 8 and he slid wide. Despite losing so much time, he completed his lap as other drivers hadn't posted times.
However, his slow lap and cautious in-lap proved to be his undoing, as Mark Webber came across Sato on the Australian's timed lap, costing him valuable time. The race stewards felt Sato had obstructed Webber and sent him to the back of the grid.
Button was equally caught out on his lap, with the bumps on entry to Turn 8 kicking up a lot of dust from the plank. Button was able to briefly steady the car, but he ran over the inside kerbs, sending the car wide, which messed up his approach to Turn 9, leaving him stranded at thirteenth on the grid.
Sato pitted on the formation lap and was filled with fuel for a long one-stop race, as Button meanwhile was unable to alter his fuel load and was able to progress by avoiding the first lap incidents. He was up to third by the time of his first pitstop and completed the race to finish fifth. Likewise, Sato pushed through his long pair of stints to end up just out of the points in ninth
One of only two teams to bring a new front wing to the race, Renault's unique endplate shape has been revised slightly. The flap above the main front wing is slightly higher and the cranked leading edge of the endplate is now squarer.
An uneventful Friday saw the team feeling well prepared for the race despite times only in the bottom half of the top ten. After his poor result in Hungary, Fernando Alonso was tenth to run his qualifying lap. The Spaniard had a particularly untidy sector 3, coming up on Barichello's in-lap and also running wide into the last turn, losing what could have been a front row start. Instead, it was Giancarlo Fisichella who started on the front row despite hydraulic problems in the pits before his out lap.
In the race, Fisichella's season-long run of bad luck continued with a fuel rig problem at his first pitstop, delaying him for over ten extra seconds.
Williams brought to Turkey a development of their Hungarian triple element front wing. The Hungarian wing used the existing main plane with the flicked-up outer tips, and the team simply added a two-part flap to improve its performance. The new wing for Istanbul, however, was a totally new shape, echoing that of McLaren in several areas, with the front profiles sweeping smoothly from the tips to a low wide centre section.
Then, the two-part flap echoes the main plane's shape and uses a very long middle chord (yellow). The complete wing fills all the available space within the box allowed by the regulation (red lines), with the centre 50cm span being allowed to both lower and longer.
This large format was present since the car's launch, but with only one slot between the two flaps, the wing would have been very sensitive to changes in attitude. Now the two slots between the elements allow a stronger flow (shown by the two arrows), which prevents the flow separating under the wing at differing attitudes.
The team also brought some new brake cooling solutions for managing the temperature of the rear discs.
Friday was not a clean day for the team, Heidfeld suffering problems with his traction control and the team still working through gear ratios and setup. Additionally, both drivers had off-track excursions during the first practice sessions.
Both drivers also had problems on their qualifying laps, with Webber running across Sato under braking for Turn 9, while Nick Heidfeld went wide through Turn 8.
A fraught race saw both Heidfeld and Webber suffer rear tyre punctures - twice each, which eventually led to both drivers retiring from the race. The cause of these accidents has yet to be fully explained. The deformation of the tyres through Turn 8 could well be the culprit, because the tyre moved around so much at that corner, that they touched the bodywork. This eventually cut the tyres and lead to their deflations.
As has been the case in the last couple of months, McLaren were on the pace with all three cars, the only problems occurring were for Pedro de la Rosa with a fuel problem stopping both him and the session on Friday morning.
Both drivers had a strong qualifying performance, and during the race looked set to give McLaren their first 1-2 finish of the season, underlining the team's domination throughout the weekend. However, while lapping the Jordan of Tiago Monteiro, Juan Pablo Montoya went into a spin after colliding with the Jordan, which damaged the diffuser on the McLaren and later led the Colombian into running wide through Turn 8 - handing Renault's Fernando Alonso second position.
With the hot temperatures expected in Turkey, Sauber have made some cooling modifications to resolve the overheating spark plug coils that forced their retirements in Hungary. Their preparation appeared to be accurate, as both drivers were very happy with the car's balance on Friday.
On Saturday, Jacques Villeneuve was victim to the bumps in Turn 8, and along with a run against the kerbs he spun and stalled the car on the track, forcing red flag to recover his car.
Felipe Massa ran his timed lap two cars after Villeneuve and was much more cautious through Turn 8, losing a lot of time at the exit.
At the race's start, Massa made a move on Heidfeld into the first corner, but as the field bunched up Massa ran out of track and hit Heidfeld, knocking off his front wing. Massa pitted for repairs and refueled for a one-stop race. Later in the race, however, the Brazilian's engine expired, forcing him to retire.
Red Bull were again running the Hungary engine cover and the extra small fence in front of the rear wheels (yellow). Friday saw the team suffering more than most over the bumps, so ride height was raised to cure the problems. However, this involved a loss of aerodynamic downforce.
Both Tonio Liuzzi and Christian Klien went off-track in the first practice sessions. Moreover, stymied by the Hungarian first lap incidents, the team had to qualify first. David Coulthard's cautious lap and error through Turn 8 saw him off his morning pace, while Klien was more attacking, with a good lap to qualify ahead of his teammate.
Both cars were safe through the opening lap and raced in close company until the first pitstop, where Coulthard was able to pass Klien. From there on, the pair battled to finish in excellent seventh and eighth places.
Friday saw the team's three drivers spread across the time sheets. Ricardo Zonta went fastest, but Jarno Trulli and Ralf Schumacher were on more conservative programmes and also were finding a good setup to match the tyres.
Trulli was the first of the pair to qualify, and a slow third sector put him behind the Renault and McLaren drivers. Moreover, his lap was surprisingly good, as he had a hefty fuel-load on board and also changed his car's setup since the morning session.
Ralf Schumacher was next out and he approached the tricky downhill Turn 9 too fast, running wide and slowing onto the run into Turn 10, which cost him over a second to Trulli.
During the race, Schumacher was an innocent victim through Turn 1, hitting Massa's errant front wing, but he did not need to pit for repairs. From there on, both drivers had a tough race with only Trulli rewarded with points for a sixth place finish.
Gearbox problems for Narain Karthikeyan and other issues with the third car cost the team some time on Friday. There was also a spin for Tiago Monteiro on Saturday, and Karthikeyan had engine pneumatic problems, forcing an engine replacement and grid penalty.
Jordan uniquely opted for a three-stop race strategy, but both drivers struggled with tyre wear and gear selection problems.
Minardi's weakest point this year has been the gearbox, and this cost Robert Doornbos a lot of time on Friday. The problems would come back to haunt him again in qualifying. He had big lock-up in Turn 7 and then completed the second sector six seconds off the pace.
The Dutchman then darted into the pits to abort his lap, but stopped the car at the pitlane entrance, where his rear brakes briefly caught fire. It transpired that after another gearbox repair, the rear brakes were not reinstalled correctly and the rear brakes were stuck on throughout his lap. In parc ferme, the complete rear suspension and brake assemblies were replaced under FIA supervision.
Christijan Albers' race was blighted by fuel rig and gearbox problems, and he eventually retired with eleven laps to go.