Sauber: F-Duct detail

The duct on the sidepod runs through the slot in the rear wing and possibly the cockpit too

Having declared they had rushed through their own version of the F-duct, we can speculate how it might work.  We know that the McLaren duct is vented into the cockpit around the drivers legs.  Then it is their leg that closes the duct to feed the rear wing.  This alters; the flow through the slot in the rear wing flap, stalling the wing, reducing drag and increasing top speed.

Sauber have already run with a vented rear wing, theirs uses the inlet on the front of the wing, to blow through a slot underneath the wing.  This allows the rear wing to be steeper without stalling, for more downforce.  Their new shark fin bulging with the duct moulded inside it, feeds into this same slot.  they could be aiming to blow even more airflow through the slot or like McLaren alter the flow to stall the wing. 

But the flow through McLarens slot is driver controlled, so Sauber need to find a way to ‘switch’ the flow on and off.  This could be done purely by the airflow being overcome by the drag creating inside the tortuous duct and hence cutting off the flow above a certain airspeed.  Or they have found a way to vent the duct into the cockpit. 

the hollow side impact spar coud lead into the cockpit to allow the vent to closed

In Saubers case the duct does not pass through the footwell of the cockpit as in McLarens case, so how might they enable the driver to seal the duct?  The placement of the duct may be gives us a clue.  It is possible that an opening exists within the side ofthe moncoque.  Sited near both the ducts inlet and running accross the frotn of the sidepod to the side of the tub is the impact spar, this could lead to an opening into the cockpit and allow the drivers elbow to seal the duct and redirect the airflow.  Its not normal for teams to want to create any opening in the side of the chassis to improve stiffness and crash protection.  But it is possible.

Therefore the driver presses his elbow against the opening at high speed to achieve the same stall as McLarens drivers get with their leg.

McLaren: choice of mirror locations for Melbourne

As McLaren set the car up for first practice, they appear to have new pod wings complete with mirrors.  This is an aerodynamically benefical location for the mirror, McLAren have been late to try this set up out.  Drivers do say the rearwards visibility is compromised, although there is a FIA static test for the quality of the drivers rear view.  Both types of mirrors are mounted with infrared tyre temperature cameras, so we can expect to see the team to alternate between the options in free practice.

Front Wing Ballast

Despite the narrow front tyres teams are still aiming for a lot of weight at the front of the car.  Slabs of ballast in the front wing are a popular method.  Teams can run over 10Kg of tungsten in the front wing profile and have nose assemblies so heavy two mechanics need to carry them.  Last year Toyota even used a trolley to help guide the heavy nose onto the car at pitstops.  There are not any rules to limit the weight of ballast in this area.

Sauber to trial an F-Duct

As we can see in these pictures Sauber have indeed prepared an F-Duct for testing in Australia. More details from the team are on Autosport.com (http://bit.ly/cSXnjh ). It seems the team are now more agile once again since they have shed the BMW ownership & management. Perhaps ex-McLaren test driver Pedro De La Rosa brought some ideas to the team

from the limited pcitures we have, we can see that the lefthand sidepod shoulder has an inlet mouded into it. this presumably feeds back through the sidepod and around theairbox to run int the shark fin. The ducting inside the sharkfin is quite evident and ends by connecting to the rear wing. it appears to attach to the mainplane (not the flap as with McLarens set up) somewhere behind the exisitng blown slot inlet.

From what we can see, it cannot becontrolled by the driver, so the duct may not be trying to do the same thing as the McLaren. Either the team rely on a a puely aerodynamic way to control the rear wing stalling, such as the duct choking at high speed and cutting off the flow the slot. Or the duct merely adds mass flow to the exisiting blown slot (raced in Bahrain) to allow the wing to be run even steeper and create yet more downforce. We will need mor eimages to be sure what Sauber are trying here.

Australia: Technical Preview

 
 
 

From a race out in the middle of the desert, F1 now hits town for Round2 in the city centre of Melbourne. Although not strictly a street race, the track is a semi permanent circuit set amongst parkland. Also the track does not conform to a street race layout, being relatively open and no tighter or slower than a lot of permanent circuits. As with Bahrain the track is made up mainly of medium/slow corners interspersed with short sharp acceleration and braking events. Only turn eleven and twelve are regarded as fast, thus they are the only heavily aero dependant corners. As a result the cars set up demands high downforce, but not the extreme set ups as seen in Monaco or Hungary. On most other statistical measures Albert Park is an average circuit, only its heavy demands on brakes set it out at any one end of the spectrum. Fuel consumption is also average; so teams will start with somewhat less their maximum of 150kg fuel.

 
 
 

Due to Albert Parks layout, we’ve still seen no fast turns to highlight the most aerodynamically efficient cars; this has been a season to show off mechanical and low speed grip so far. With its multitude of right/left complexes, Melbourne is regarded as a ‘front end’ circuit, prone to inducing understeer and graining front tyres. Thus any team with out their tyre warm-up and aero/weight balance sorted will struggle this weekend. The tyre situation is also exacerbated by the green track. As the track is not used inbetween F1 events, the surface is clean of rubber build-up. This of course improves over the course of the weekend, so teams will have compensate for the increasing grip as they set up the car over the opening sessions.

Teams and drivers alike will be glad to be rid of the extreme bumps of sector2 in Bahrain, but Melbourne is still regarded as a bumpy track and the corner exits are lined with ridged kerbs, so the cars tends to run over these a lot over the course of the weekend. Thus teams set up options for ride height and spring rate will need to be carefully considered. At least Bahrain provided the teams with some real experience with heavy fuel and the new tyres, so they now better understand what is required to get the car working over the weekend.

Race strategy will be tricky as the soft tyre will be preferred for qualifying, being 1s per lap faster, but was degrading rapidly in the race last year. Thus the soft is better suited to a late race stint, when the tyre will work better on the rubbered-in track. An early stint with the soft option could cost 5-6 seconds, making a tough call for the strategists with cars qualifying in top ten and starting on their qualifying tyres. Despite the short pit lane, race strategy is expected to follow Bahrain with a single stop to switch tyre compounds. Unless of course a safety car is deployed, this is likely due to the street circuit nature of the track and in particular turn1 on lap1. Even more than one safety car period could be likely, reacting to any event is likely to pay dividends for any teams getting the calls right. Especially if the option to get off the soft tyre in the opening stint arises, leading to a long stint on the more durable harder tyre. However this will be an ideal early season view of which teams are easy on tyres. Last year Brawn were able to run the soft tyre over two stints, but suffered with tyre warm up later in the season at races in colder conditions or on harder tyres.  In contrast to Red Bulls greater tyre warm up, but worse degradation in 2009.

The weather will play its part too, rain could be expected. But more likely it will be hot and get cooler through the race as the sun starts to set, creating visibility problems for the drivers. A least the teams will be able to run more efficient bodywork compared the extreme cooling set ups used to meet Bahrain’s demands.

The cars were freighted direct to Australia from Bahrain, thus they haven’t been back to the factory. More parts will have been shipped from the teams’ respective bases, but we can expect to see only a few developments in Melbourne. Under the skin the cars will probably feature more detail upgrades to attend to issues raised on the ‘fix lists’ created over the opening GP. Additionally four teams have had to amend their diffusers to meet the clarification on the starter hole size. McLaren, Mercedes, Renault and Force India all have to amend their floors. This could either involve a new floor entirely or simply a revised section bonded onto the original floor. Performance wise the changes would not be expected to be noticeable.

 

 
 
 

Team by Team

Mercedes

Strangely Mercedes seem to be behind the curve on adjusting to the new tyres. As the W01 does not seem to have the same levels of grip and balance, as its rivals. A continuing belief is that the car carries too much weight, too far forward in the chassis. While it’s true that the Mercedes still carries its huge slab of ballast in the front splitter, switching to a more rearwards weight split is relatively easy. It’s certainly easier to shift weight backwards than forwards, as there is more space around the gearbox for ballast. So perhaps the problem is the front to rear aero split, which tends to be a few percent off the weight split. Creating more rear downforce, costs drag if done with the rear wing, so a more powerful diffuser is required. One option is that the cars created the ideal weight balance and matches its aero with less total downforce, but a correct split front to rear. If these are indeed the problems then the car will need a new floor and front aero to correct the issue. This will probably take until Spain certainly china at the earliest. this issue resolved I can see no weakness in the car that prevent it taking race wins, it will just be that several races have passed by and their rivals championship leads will be extended. Melbourne may not suit the car with its dependence on front end grip, the team may have some workarounds, but it’s likely its Spain they are most looking forward to.

Ferrari

Despite a race win, a warning call went out Ferrari that Red Bull are at least their equals. Whether Alonso could have overtaken Vettel if it were not for his reliability problems is debatable. However Ferrari are at least on the pace this season and testing and Bahrain have demonstrated the team reliability. cooling was of course an issue for the team and two engines changes before qualifying shows the teams, ran in several sessions with non-optimal cooling before they had the set up correct. But Bahrain is an extreme case for cooling and the problem should not be overblown. Bahrain also showed the Ferrari to handle the bumps well, a sign that the mechanical set up is good, and this will pay dividends in the bumpy braking zones in Australia.

McLaren

After the promise in testing and the furore over the stalling rear wing, Mclarens actual pace over the Bahrain weekend was a disappointment. The car appeared stiff and lacked the team’s usual supple suspension over the bumps in sector2. McLaren put this down to set up errors and a direction taken early in the weekend regarding the unexpected bumps out of turn5. With a different approach and less bumps in Melbourne McLaren should be able to demonstrate the potential in their package. In the latter stages of the Sakhir race the team were fast, so an early sign of pace will be critical this weekend.

Martin Whitmarsh has been quoted that the car will have new parts this weekend, but only “a number of smaller components” presumably in addition to the revised diffuser starter hole that Whitmarsh claimed was the same size as Brawn had last year, a view in contrast to my observations of the current McLaren floor. Continuing to use the f-duct (the snorkel fed rear wing slot) pictures of the cars cockpit seen on autosport.com showed the duct appears to pass the drivers elbow affixed to the left side of the cockpit. Sakhir demonstrated no obvious speed advantage for the mp4-25 so perhaps the car is set up with extra downforce for the corners and the stalled rear wing only maintains the same top speed possible with a smaller rear wing.

Red Bull

Having kept under radar in testing and Bahrain Free practices, it was only in qualifying that RBR showed true pace. Lewis Hamilton’s comments should be taken with a degree of scepticism, but it’s true enough to say the Red Bull does have an advantage over many cars, Ferrari excepted. This sees their pace from 2009 carried over into the new season. If the rb5 shows well in Melbourne then perhaps the team have also added the grippy mechanical set up to the team’s well-known aero advantage. It’s likely that other teams will be closer to Red Bull this weekend, as they get to grips with heavy fuel weekend set up.

So far the only chink in Red Bull armour is reliability; this was suspect in testing and continued to be through the Bahrain weekend, a race victory lost will be additionally high with this year’s points system. Red Bulls aim this weekend must 100% track time and nothing given up to frailty with thin the car or its engine.

Renault

Renaults upgrade package for Bahrain clearly paid off, with a successful weekend for the team. with a strong qualifying in the midfield and showing better race pace the team are reopen the rewards of the wind tunnel upgrade over the winter, the downtime now being offset with a more aggressive development programme. This aggressive approach is underlined with another new front wing this weekend in Melbourne and what Alan Permane described as “a new part on the rear wing, which improves our overall downforce”. not just the chassis but also the engine as Renault announced several upgrades to their engine which have been given FIA approval, which despite the engine spec freeze, still fits in with the framework that allows reliability upgrades to be made, if that results in more power then the team are onto a double win from the changes. One other mechanical area that needs addressing, but will not be ready for Melbourne is the front suspension that saw a failed front pushrod for Petrov in Sakhir. His preferred ride height lead to parts fouling and the pushrod loosened where the titanium top section meets the carbon pushrod.

If the team can improve their qualifying and get through the first laps in position then they can expect points from the Australian race.

Williams

A flat performance in Bahrain must have disappointed the team as the winter showed more promise from the compact FW32. With Renault and Force India on-form, the team will need to put in a better result in Albert Park to stand clear of the midfield. To help achieve this Technical director Sam Michael said that some development will be tried on the car on Friday. 

Force India

After a good qualifying performance from Sutil in Round1, only his inherent ability to get involved in tangles with other cars upset the team’s race. In its effort to get the bodywork to cope with the Bahrain heat, the car appears to have been handicapped by excessive drag from all the bulges and openings in the sidepods. With lower temperatures the team should performs relatively better in Australia. As well as the announced changes to the front and rear wing, there are suggestions that another new nose will be ready for this round show that the team are really focussing on the chassis and getting developments made and on to the car. This rate of development will be important in the tightly packed mid field. 

BMW Sauber

Bahrain was not the fast starting performance the team would have wanted. The car struggled on the bumpy track more than their rivals. Sauber like a very low ride height, with this comes compromises with stiff suspension and grounding over bumps. Unable to get the grip and control they needed the poor qualifying performance hindered their race. However like McLaren their race performance was far better than q suggested. However both cars retiring with unrelated hydraulic faults are another warning sign for the team both at the track and with the design and production people at the factory.

While the reliability is suspect the design innovation apparently isn’t as Sauber are rumours to have their own version of the McLaren F-Vent ready to race. Its not clear how accurate this rumour is, or whether the development is a reaction or parallel development to McLarens set up. Keep a close eye on the rear wing over the course of free practice!

With a demand for more downforce and less bumps in Australia, along with revisions to their set up and weekend strategy should see Sauber in a closer fight with their rivals. Weekend preparation started early for the team with Kobayashis’ debut in Australia being eased by the drivers using the ex-Toyota f1 simulator for practice.

Toro Rosso

The promise shown by the team in 2008 seems along time ago now; it seems the old Minardi days are closer than Vettels’ win in Monza. The Toro Rosso designed and produced ST5, is only lightly revised STR4, which in the teams hands struggled to get off the back row last year. All the other teams have moved on the double failure to get into Q2 showed. It’s hard to see that the team will lift its pace at a greater rate than their competitors.

Virgin

Despite the lead time for the project the VR01 still struggles with reliability. Through out testing the car was stymied by a hydraulic issues and the race saw issues for both cars, one hydraulic failure and an overheating gearbox. Virgin confirms they have diagnosed and now have parts to resolve the issues, adding “Every effort is being made to ensure there isn’t a repeat of these issues.”. But still wheels falling off in free practice is not acceptable at this level. When running the car has shown promise, even overtaking a lotus in the race. But we need to see a long run from one of the cars to prove if the progressive design has the potential is promises.

Hispania

A new team with a new car making its first run in free practice on a Friday is tough debut for a team. Having got one car out on track and just scraping the second through in qualifying must be seen as an achievement, but is this really the level we expected the new teams to operate at? Especially, as the team with the longest lead in to the first race and the backing of experienced car constructor Dallara. With their baptism of fire out of the way it will be interesting to see how the team fare on their second race weekend. There are signs of greater resources available to the team as Chandock commented before the race he “was able to work on a team’s simulator” although this is likely to be a third party simulator than the teams own.

Lotus

Shading their new team rivals with a reliable run through free practice and race, lotus two car finishes and qualifying result were a good sign for the team, especially considering they had the shortest lead time to deliver the car. Equally the presence of new aero parts shows the team are progressing rather than just bedding in. The new rear winglet and shark fin made debuts in Bahrain. The winglet made it to the race but the shark fin was just for testing. Additionally the team have new parts ready for this race, with a new beam wing and front bargeboards. With their head start the team mow need to start consolidating this position and working towards reducing the gap to Toro Rosso, which for lotus and perhaps virgin is a potential scenario by mid season.