Jenson Button, McLaren, Barcelona, 2011

Pre-season technical review

2011 F1 season previewPosted on Author John Beamer

Jenson Button, McLaren, Barcelona, 2011
Jenson Button, McLaren, Barcelona, 2011

Guest writer John Beamer reviews the innovations on the 2011 F1 cars revealed so far.

As the fourth pre-season test begins it is still difficult to judge the 2011 pecking order. But we can draw some informed conclusions about the general picture.

Common wisdom pegs Red Bull and Ferrari out in front with Renault and Williams vying for third and fourth, with McLaren and Mercedes further back. Yes, you did read that correctly!

But remember, this is only testing and there are many further developments to come. If you believe the utterances from the McLaren garage, they treat it differently to say a Red Bull or a Ferrari.

McLaren?s public position is that pre-season testing is the one opportunity to correlate on track performance with the wind tunnel and CFD. That?s partly why the MP4-26 trundles around the track looking like farm machinery.

While that is true to extent everything else points to the new McLaren being woeful. To understand why this might let?s first look at what Red Bull and Ferrari have done right.

Red Bull RB7

Sebastian Vettel, Red Bull, Jerez, 2011
Sebastian Vettel, Red Bull, Jerez, 2011

Superficially there are few if any radical innovations on the car ?ǣ no trick exhausts or U-shaped sidepods.

And you?d be worried if there was. This is a car that won ten races last year and had a 0.5s performance advantage at the end of the season. Instead what Adrian Newey has done is continue to focus on optimising the car to eek out every last millisecond of performance.

The biggest change has been to the sidepods and cooling setup to try to improve the airflow in the ‘coke bottle’ zone and over the diffuser. As was apparent in the double diffuser era getting clean air to the rear of the car is crucial for good downforce.

When the RB5 was launched one way Newey made the rear end slimmer was to place a cooling outlet in the centre of the car above the gearbox. However, there were still some cooling ducts aft of the radiators in the coke bottle zone.

The RB7 has eliminated these and routes all radiator cooling to the central duct. This allows the ‘coke bottle’ to be super-slim and expose more of the floor surrounding the diffuser to clear air.

The other major visual change to the RB7 is to the exhausts. Last year Red Bull pioneered the exhaust-blown diffuser (EBD) and has a lot of experience with the system.

This year teams are trying all sorts of exhaust tricks and the Red Bull solution is to route the exhausts to the 50mm zone at the edge of the diffuser where a cut can be applied to allow the exhausts to route under the diffuser. Look carefully in the ‘coke bottle’ zone and you?ll see a raised angled section between the engines and the edge of the floor ?ǣ this carries the exhausts.

Ferrari 150??? Italia

Felipe Massa, Ferrari, Barcelona, 2011
Felipe Massa, Ferrari, Barcelona, 2011

When first launched many thought that the 150??? Italia was a tad conservative. The team retained push rod rear suspension configuration, the sidepods weren?t as hugely undercut as other teams? were and, well, the car just didn?t look particularly radical.

However, in other ways the car was different. By retaining a push rod layout Ferrari is now in a minority. In some ways this is a bigger call than adopting a pull rod layout given it was perceived wisdom that pull rod was the way to go. No doubt the Ferrari designers spent hours debating this.

Ferrari has changed the suspension layout at the rear and slimmed down component packaging. For instance there are no visible bulges housing the rockers and dampers. It appears Ferrari have dropped the rear torsion bars so is effectively running with no rear side springs, allowing the suspension componentary to be further reduced.

Last year there were suggestions that Ferrari ran interconnected suspension i.e., linked the front and rear axles as this allows better control of the cars? attitude to create more consistent downforce from the floor and diffuser. Ferrari blows the exhausts over the centre of the diffuser and pass some the gasses through the starter motor hole to create more downforce.

So far in testing the car looks quick. It isn?t a radical car by any stretch but like the Red Bull it is an evolution of its predecessor.

McLaren MP4-26

Lewis Hamilton, McLaren, Jerez, 2011
Lewis Hamilton, McLaren, Jerez, 2011

In 2009 McLaren launched its worst car in a decade. In testing the MP4-24 was some 2.5s off the pace as the McLaren designers interpreted the new regulations very conservatively.

Meanwhile Brawn pioneered the double diffuser, which meant their car stuck to the track like araldite and the allowed Button to establish such a dominant lead in the first half of the season that it didn?t change the outcome when other teams finally caught up.

You can imagine the conversation in Woking, ??Damn those Brawn boys ?? next year we are going to product the biggest and most powerful double diffuser in the galaxy??. And that is what McLaren did.

The MP4-25 was designed around a huge double diffuser. Sure, peak downforce was impressive ?ǣ I bet the wind tunnel readings were off the scale – but to use the double diffuser the car had to be set up incredibly stiffly, which meant it was susceptible to even the smallest bumps and was pitch sensitive in the extreme. It turned out that shooting for more consistent downforce led to a better lap ?ǣ both Red Bull and Ferrari produced a more supple car that was ultimately faster than the McLaren.

Also during 2010 testing the McLaren designers see Adrian Newey wheel out trick exhausts and further refine the rear cooling and suspension arrangement to maximise airflow over the double diffuser. Now fast-forward to 2011 and picture the conversation as the design team snuggled around the boardroom in the design office, ??To beat Red Bull we need to come up with the craziest exhaust system and a wacky idea to optimise airflow to the rear wing.?? And here we are with an exhaust system that melts the under tray and L-shaped sidepods that at first blush are not producing sufficient rear grip.

McLaren MP4-26 launch, Berlin, 2011
McLaren MP4-26 launch, Berlin, 2011

Let?s take a closer look at some of the innovations of the MP4-26. The two major talking points are the sidepods and exhausts. There are two exhaust configurations: a now standard rear exiting exhaust which blows gas over the top of the diffuser; and a trick exhaust that exits forward of the gearbox to energise airflow around or under the floor. No one is quite sure where the trick exhausts exit but photos show a very clear U-bend as the exhausts exit the engine. Indeed there were even suggestions of multiple exits for the trick exhausts but these are unconfirmed.

In the first two tests McLaren ran a series of back-to-back experiments with the exhaust systems to try to baseline the downforce improvement. However, its unclear whether there was any improvement and when McLaren announced that they were hampered by a shortage of components it pointed to insufficient heat shielding at the exhaust exits.

It will be interesting to see the configuration McLaren opts to race with in Australia ?ǣ if it is the standard exhaust set-up then they will be writing off millions of pounds worth of exhaust research.

The other innovation is the U-shaped sidepods. The theory here is that the U-shaped sidepods increase the air flow to the beam wing. This in turn reduced the pressure gradient above the diffuser and results in more downforce.

There are some compromises to this approach. First the radiator inlets need to be bigger. This is because the inlets are in line with the front tyres which generate dirty air. The more energized the air the better the cooling performance.

Also the radical shape means the McLaren sidepods are less undercut that some of their challengers. This will restrict the flow to the coke-bottle zone around the side of the car. The balancing equation is whether increased flow over the centre of the car more than offsets the complex radiator set-up and reduced undercut.

Renault, Williams, Toro Rosso

Nick Heidfeld, Renault, Jerez, 2011
Nick Heidfeld, Renault, Jerez, 2011

Three other teams have produced significant innovations in the off-season: Renault, Williams and Toro Rosso. They are all looking to solve the same two problems that McLaren were, namely how to optimise the use of exhaust gasses and maximise rear downforce in the wake of the new diffuser regulations.

Renault sprung a surprise on the other teams with its innovative new exhausts. The exhausts route from the engine underneath the radiators and exit at the front of the sidepods and point under the floor. Exhaust gasses will drive a higher volume of airflow to the diffuser which increases downforce.

The challenges are twofold. First, the exhaust pipe runs at about 800C so a lot of heat shielding is required. Second, the engine mapping settings need to ensure there is a consistent flow of air to the diffuser especially during corner entry when downforce is needed and the drive is off the throttle.

Pastor Maldonado, Williams, Barcelona, 2011
Pastor Maldonado, Williams, Barcelona, 2011

Williams and Toro Rosso have focused on pushing more air over the diffuser. As mentioned earlier this create lower pressure above the diffuser, which means the pressure gradient is lower. This generates more downforce and is better for consistency as airflow stays attached in the diffuser.

Williams? solution is to aggressively shrink the gearbox to create a super-tight ‘coke bottle’. By reducing the blockage ahead of the diffuser the airflow over the device is much cleaner and also lowers the centre of gravity. The smaller gearbox has ramifications for the drive shaft which is now angled at about 15 degrees into the gearbox.

Typically an angled drive shaft costs reduces the power transmitted to the wheels so this will have been an area of focus for the gearbox engineering team.

Jaime Alguersuari, Toro Rosso, Barcelona, 2011
Jaime Alguersuari, Toro Rosso, Barcelona, 2011

Toro Rosso have taken a different approach to Williams by creating a double floor. Effectively the sidepods are raised above the floor creating an incredibly deep undercut. This allows air to channel in a gap between the sidepods and floor with the intention to drive better quality air over the diffuser.

The challenge with this approach is that, unlike the Williams design, the car?s centre of gravity is raised, which compromises handling.

Rear wings and Pirelli tyres

Along with innovation from the teams there are a host of other factors that will affect the racing in 2011. The two most significant are the Drag Reduction System (moveable rear wing) and the Pirelli tyres. There are mixed views on how both of these will affect the races.

Expect the rules on the rear wings to be conservative in the early races. The device can only be used once per lap in a designated area, which is likely to be a maximum of 600m in length.

The rules are reasonably fluid as the FIA has reserved the right to tweak the application of the moveable wing after the first four races ?ǣ expect the FIA to make use of this power.

The new tyres are an altogether different matter. Evidence from the first few tests suggest that the tyres are 1.5-2s slower than the Bridgestones.

That isn?t surprising: Bridgestone was in the sport for nearly two decades and was involved in tyre wars with both Goodyear and Michelin.

The construction of the Pirellis is far stiffer and getting heat into the tyres is harder. As a result wear is rapid and the tyres are quickly wearing out. They are also producing a lot more marbles, which could have consequences for overtaking.

At this time of year we inevitably have more questions than answers about the cars. Bring on Melbourne!

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