24/04/2013
FEATURE BY MATT SOMERFIELD
Round four of the 2013 championship was hosted at the Sakhir circuit in Bahrain, a circuit often criticized by media and fans alike for a lack of action. I think this year's race seems to have dispelled that somewhat with overtaking up and down the field throughout the race.
Initially Pirelli had opted to supply the Soft (Option) and Hard (Prime) tyres for Bahrain but in a decision made before China the Italian tyre supplier made the switch from Soft to Medium tyres. Having seen high degradation levels in China from the Soft tyre it's a move that on the face of it seems prudent due to the increased temperatures also yielding more thermal degradation. This however was the first time this season we haven't had a step between the compound choices resulting in a smaller tyre deficit delta. This narrows the strategy opportunity resulting in around 0.4 - 0.5 secs difference per lap from compound to compound rather than the 0.8 - 1.0 differential we have had in previous races. Drivers who perhaps felt they could gain an advantage from qualifying in Q3 on the Prime tyre and run longer into the race found that in the early stages of the race the tyre differential in terms of time wasn't as significant as they'd hoped whilst the Option tyre also held on equally well.
The reason for this is the operating temperatures of the Pirelli line-up.
Super Soft (85°-110°)
Soft (105°-125°)
Medium (90°-115°)
Hard (110°-135°C)
With the Medium tyre working in a much lower temperature window, at a high temperature circuit like Sakhir the tyre will thermally degrade much quicker, especially as the target window of operation for the car in race trim will edge toward the Hard compound.
The Bahrain Grand Prix ran back-to-back with the Chinese Grand Prix and therefore the teams were unlikely to all have significant upgrade packages available. F1 however is a development race where as much as 2 seconds of lap time can be found over the course of a season and so the teams will always strive to bring as much as possible to each race.
Red Bull re-introduced a blown front axle in Bahrain, (only fitted to Vettel's car) I say re-introduced as the team ran a version in the 2012 season. Having completed several races with their blown axle in 2012 the team was asked to remove the device in Montreal as its design allowed the airflow to escape through the rotating section of the axle which is illegal (Moveable Aerodynamic Device). When Williams introduced its blown axle design in pre-season testing it wasn't a huge leap to suspect Red Bull was a team that could glean an advantage in this area considering its previous use of such a design and so I'm not shocked to see them try it. The blown axle setup wasn't raced in Bahrain but I suspect the team may evaluate it again in the future.
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One thing the team did race was a change to the design of its Rear Wing Endplate Louvres, previously arched away from the wing profiles (left) the new louvres (right) represent an ethos employed by many other teams up and down the grid.
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Furthermore I mentioned an area of interest in my China round-up on the RB9 just ahead of the rear wheels. Images captured during that race led me to believe there may have been a cut in the floor between the now twin vertical floor strakes that adorn the RB9's floor. Pictures provided by Sutton Images however debunk my original thoughts but enforce the lengths Red Bull is going to in order to control the natural airflow and the exhaust plume in the region. The use of rapid prototype parts in this area bonded to the floor suggests the team is experimenting throughout the weekend to engage a permanent solution for the area, reducing Tyre Squirt and increasing Diffuser efficiency.
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Lastly due to the increased track temperatures the team opened up a section of the top edge of the engine cover cooling exit as pictured below.
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At the other end of the grid, Caterham has started its 2013 campaign essentially with its 2012 challenger. The team has clearly stated since the start of pre-season testing that it would target Barcelona as the race to introduce a package of upgrades that will bring it in line for 2013. Having been bested at the start of the season by its closest rivals Marussia it comes as no surprise the team stepped up its efforts to be on target for the Barcelona upgrades. Before the Bahrain weekend it was announced that Heikki Kovalainen would once again work with the Caterham team, taking the place of Giedo Van der Garde for the Free Practice session on Friday morning in order to assess the planned upgrades for Barcelona. The Finn's acumen behind the wheel, allied with his previous experience within the team, made perfect sense, along with the placement of him in Van Der Garde's seat rather than Pic's. Pic has a year's more experience in F1 than his Dutch counterpart, albeit with another team, this places him in a better position to complete the normal qualifying and race programme desired by the team.
Kovalainen's assessment of the CT03's upgrades was one full of positives and so the team decided to bring forward its plans and continued with the upgrades throughout the weekend, placing them on Pic's car.
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As you can see in the image above I have indicated some of the keys aspects that were amended in the upgrade package:
1: Under Nose Bulge - the addition of a bulged section under the nose has been implemented up and down the grid with Red Bull, Lotus (the most aggressive application), Force India, Sauber, Williams and even its closest rivals Marussia sporting such bulges throughout 2012/13. The idea is to manipulate the airflow under the nose to better utilise the turning vanes and move the airflow more effectively toward the Sidepod and Bargeboards.
2: Sidepod Airflow Conditioner - Caterham has run a twin element component here since the middle of 2012 but the team has now arc'd the secondary element to meet with the Sidepod's top edge forming part of the outer Vortex Generator. You will have seen this type of unification of the two elements on both the Red Bull and Sauber before them but Caterham has chosen to retain the more forward section of the element at full height which in itself will also create a trailing Vortex.
3: Bargeboard - Hidden in this picture behind the wheel, the team has made a small revision to its bargeboard, removing a small section at the top of the element. This is a likely revision due to the under nose bulge already mentioned.
4: Rear Wing Mainplane - The old specification mainplane on the CT-03 was a fairly blunt airfoil whereas the new component features a centralised section with a more aggressive profile. The more aggressive leading edge changes the Rear Wing's philosophy somewhat and so needs to be tied to the changes made at number 5.
5: Rear Wing Endplate Louvres - Louvres help to manage the Vortex generated at the joint where the Endplate meets the Mainplane and Top Flap. If we take a Wing without Louvres we would see that as the high pressure air moving between the Endplates rolls over the back of the wing profiles it merges with the air coming around the outside of the Endplates, this air pressure is lower and therefore as the two interact they spiral creating a Vortex. This spiralling Vortex of course increases with speed affecting a more widespread area (migrating across the width of the Wing) increasing drag. Louvres therefore help airflow to migrate ahead of the wing from the high pressure side to the low pressure side, reducing Vortex drag.
6: Rear Wing Endplate Strakes - Not shown in the image (hidden behind the rear wheel) - Toward the end of last season Caterham started using Strakes at the lower end of their Endplates, these help to manipulate the airflow toward the edge of the Diffuser, usually by virtue of moving airflow across to the gap between the Diffuser's edge and the Tyre. Of course with the change to this year's tyres we have been seeing other teams make the same alteration to the Strakes which is a reduction in their length.
Caterham's upgrades propelled Pic ahead of the Marussias for the first time this season but more interestingly draw them much closer to the likes of Williams and Toro Rosso.
As I alluded to earlier, I firmly believe the Bahrain GP offered the best racing we have seen since F1 started visiting in 2004. The first few laps of the race saw the vying for position of Rosberg, Vettel and Alonso at the front, whilst Di Resta, Raikkonen, Webber, Button, Perez and Grosjean battled out for the mid points.
Rosberg on the Medium tyres struggled to hold off the fast charging Vettel who was seemingly having a better time on the Option tyre. As previously mentioned this has more to do with the way in which the tyres thermally degrade. Mercedes has most certainly made fantastic strides in resolving the issues the team had with the W03 but Bahrain was the first time we have seen representative temperatures and once again it seems both drivers struggled holding onto the tyres. I'd almost suggest that Rosberg took a little too much out of his tyres during Qualifying resulting in him struggling in the early stages of the race. However, if we also take into account Hamilton's comments about the car lacking balance, then look at the way the car performed during Qualifying and the end of the race we can conclude the issue (in Bahrain at least) comes either from a tendency to lean too heavily on the tyres mechanically whilst fuelled up or from a dependency aerodynamically to a window of ride height.
Paul Hembery of Pirelli tweeted before qualifying: 'Would have forecast 3 stop race before FP1, looking at it now, impression is some can do 2. Will look at the data after FP2'.
This of course is extremely important, as a pit stop in Bahrain is around 19 seconds, thus affording the likes of Raikkonen and Di Resta a buffer of those 19 seconds of track time in order to make 1 less stop. The problem however is that buffer can be eaten up quite quickly not only through having to manage one less set of tyres but through traffic that may be encountered. Raikkonen's first stop found him amongst the traffic making the job of looking after the second stints tyres even more difficult, having to follow and overtake cars that are at a different stage in their race.
At the other end of the spectrum Vettel, who had cleared such traffic problems early into his race, was still being managed by the pit wall, with Rocky (Vettel's engineer) instructing him of target lap times. We can therefore see that Red Bull is still very wary of how crucial it is to qualify well and that it must manage the tyres throughout the whole race.
Force India once again showed signs that the team has made a stride forward with the VJM06 and although many will say the car is simply an evolution of the 2012 car I would argue that it is around 80% a new car but the team has developed areas from last year's car very well. Its tyre management and understanding is also clearly giving it an advantage compared to the other teams around it.
McLaren once again was working on damage limitation ahead of a crucial upgrade for the MP4-28 scheduled for Barcelona. We still find the team in a position it won't like, scrapping for mid-late point positions, but I have to say fair play to the team for letting its drivers scrap it out even if Jenson wasn't amused.
Ferrari rather had its hand forced in terms of strategy with Alonso's failing DRS actuator and Massa's poor luck in picking up tyre damage (caused by debris). Ferrari fans needn't be glum though as it's quite clear the F138 is a strong car with Alonso making a stellar recovery to 8th without the use of DRS.
Having looked at the Pirelli tyres in my last technical roundup I thought I'd cover another contentious issue for fans this time around, DRS.
DRS was introduced in 2011 by the FIA in order to overcome a problem encountered in Formula One when one car follows another. You will often hear commentators refer to a driver being caught in the 'Dirty Air' or 'Wake' of the car in front losing them lap time. The FIA tried to remedy the situation when it first introduced the current rule set in 2009 by allowing the driver the ability to adjust the Front Wing angle by 6 degrees twice a lap. The introduction of the Double Decked Diffusers (DDD) of that year put pay to the usefulness of the tool with the 'Wake' being produced overcoming an angle change that was being made by the driver. Many drivers simply used the Front Wing adjustment as a tool to balance the car instead and thus in 2010 the Front Wing adjusters were removed from use. In 2010 McLaren introduced its RW80, or as the media dubbed it the F-Duct, perhaps inadvertently the Woking based squad had answered the prayers of the FIA, for it paved the way for the governing body to introduce DRS in 2011 with the F-Duct showing just how effective reducing drag on the rear wing could be for overtaking.
DRS has and will continue to be controversial amongst fans who feel its use for overtaking is artificial and to some extent I agree. But we cannot deny without it some races would return to a nose-to-tail affair where one driver cannot break the 'Wake' of the car in front sufficiently through the corners to enable a pass along the straight. I questioned the FIA's decision at the start of this season to limit DRS only to the designated zones as it took away an element of strategy for the teams. In previous seasons the team was able to manipulate the way in which DRS could be used in its unlimited format during qualifying and restricted capacity during the race (Delta). This to me enhanced the racing as it represented a distinct choice by the team as to whether it would either sacrifice performance in qualifying or the race. The playing field has been somewhat levelled this season with teams simply selecting the maximum gearing and rear wing design that will enable Vmax on the longest given DRS zone for Practice, Qualifying and the Race and so an element of strategy has been lost.
Furthermore this season I have yet to see race control make alterations to the length of the these zones during a race weekend making it altogether too predictable for the teams and making overtaking a little too easy for my liking.
The initial aim of DRS was to enable a driver to get alongside his opponent in the latter part of the straight so that they can dice for position into/out of the corner. This season I feel this has been lost and many overtakes are happening far too early along the DRS zone. A far more effective way, and something that would bring an element of strategy back, would be to continue to publish the designated DRS zones for the Free Practice sessions. When FP3 concludes race control then has more data available to it allowing a considered view of where the activation point should start and end. The teams would then have to extrapolate a setup in view of both qualifying and the race.
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Lastly, whilst on the topic of DRS I'd also like to mention something that I noticed during Sunday's race and that is the use of DRS when not in an activation zone. I thought I had seen this happen at previous GP's but downplayed it, that is until I saw Alonso use DRS to attack Rosberg at the end of lap 3. Alonso realized his mistake however and before the end of the straight allowed Rosberg back past.
How did this occur you may ask? I thought the drivers could only use DRS when in the activation zones? The only answer I have is that the SECU problems the FIA has been having this season has meant the steering wheel dash prompts received by the drivers for flags etc haven't been working as they should. In terms of DRS I'm quite sure the driver receives the signal they should do after the detection point that DRS will be enabled but I'm not so sure that it's locked out of use until the activation point like it should be. (I'm trying to get clarification on this).
The other issue that comes out of this incident is that it could be the root cause for Alonso's DRS failure, the footage available to me shows a graphic that Alonso closed the DRS at around 120 mph (190 kmph) to allow Rosberg to come back past and then reactivated it. For Alonso this would simply mean lifting his left leg off the foot operated DRS and re-applying it. The problem with this is the forces involved at that sort of speed - i.e. re-opening the flap at 120 mph (190 kmph) - far exceed the usual operating window of the mechanical components and likely stressed the actuator. As we can see in the image below the actuator pod has actually separated allowing the flap to go beyond the 50mm opening allowed by the rules. Lastly on this topic I'd like to say that Alonso completed laps 5 and 6 with DRS open throughout the entirety of the laps, posting lap times representative to others in the field when in reality he should have no right to do so stripped of some of the Rear Wing's downforce.
We now have a three-week break in track action during which time the teams will be working hard back at their factories to rectify the issues from the first four flyaway races of the season. With Barcelona the first race of the European leg we can expect a flurry of activity in terms of upgrade packages especially by those teams caught out by the change in aerodynamic/tyre dynamics of this year's Pirelli's.
Note: All pictures can be found in higher resolution here.