Sebastian Vettel, Red Bull, Interlagos, 2011

How the 2012 rules will influence F1 car design

F1 technologyPosted on | Author John Beamer

Sebastian Vettel, Red Bull, Interlagos, 2011
Red Bull have been the class of the field in recent years

The 2012 season is the first since 2008 without significant changes in the technical regulations.

In 2009 we saw a reduction in aero appendages, refuelling was banned the following year, and the 2011 season was shaped by new Pirelli tyres, the introduction of DRS and return of KERS.

We’ve already had our first glimpse of a 2012 F1 car, but what will the other teams have in store for us this year?

Continuity and change in the 2012 rules

With the next major change coming in 2014 the rules for this season have undergone comparatively minor revisions. But there have been several tweaks which will make life interesting for F1 designers.

The changes include the banning of exhaust blown diffusers, restriction on engine mapping and a lowering of the maximum height of the front bulkhead. Further minor changes include a tighter definitions of how anti-stall systems must work and the extent to which wheel uprights can extend inboard.

One potentially significant change for the 2012 season which never materialised was a relaxing of the restrictions on weight distribution.

These were imposed last year due to the unknown characteristics of the new tyres. They acted as a safety net to ensure none of the teams got this fundamental aspect disastrously wrong and endured a season well off the pace.

One team with recent experience of this is Lotus, formerly, Renault. In 2007 the team failed to understand how the weight characteristics changed after switching from Michelins to Bridgestones, and endured a win-less season having won back-to-back championships in the two previous years.

The FIA originally intended to relax the weight distribution limits for the 2012 season. Its U-turn removes a wild card that could have shuffled performance among the top teams.

The exhaust-blown diffuser ban

Jaime Alguersuari, Toro Rosso, Suzuka, 2011
Exhaust-blown diffuser improvements spurred Toro Rosso late in 2011

The most significant rule change is the banning of exhaust blown diffusers. This is achieved by rules which dictate the position of the final 10cm of exhaust piping. The rules specify that this section must be circular, thin-wall and 75mm in diameter. This prevents odd-shaped exhausts with vanes to direct airflow. Teams can have no slots along the length of the exhaust so McLaren’s unraced ‘octopus’ exhaust wouldn?t be allowed.

An area for the exhausts’ exit is also defined by the rules. The FIA has also specified maximum and minimum exhaust angles. The limitations are not too restrictive but should move the exhaust exit some way from the floor area and prevent teams from blowing gasses close to the car’s bodywork.

F1 teams have spent an inordinate amount of money on perfecting exhaust blowing technologies over the last two years and the suspicion is that engineers will still be able to use that capability to blow exhaust gasses for some aerodynamic benefit. There are a number of possible options for where teams can blow exhaust gasses.

The obvious solution is to aim the exhaust at the rear or beam wing ?ǣ this is possible under the dimension restrictions in the regulations. Aiming the gasses at the underside of the wing at the car centre line will help keep airflow attached to the element and should result in a downforce increase. However, the interaction with DRS will be complicated and needs to be understood.

Valtteri Bottas, Williams, Abu Dhabi, 2011
Williams experimented with exhaust placement at the Abu Dhabi test

Another alternative could be to point the exhausts down outside the rear wing endplates and try to manage the wheel/diffuser interaction. In this set-up it may even be possible to create downforce around the suspension arms. But this is likely to prove a very difficult solution given the intricacy of the suspension and brake ducts in this area. And the distance between the area and the exhaust exits may make directing the gasses with sufficient accuracy impossible.

A further option is to blow the exhausts into the gap between the diffuser and beam wing. This shouldn’t have a huge effect on downforce but could aid airflow in the coke bottle zone. Lastly, the exhausts could be aimed out and away to prevent the gasses from interfering with the aerodynamics – but which designers would be happy to sacrifice the potential downforce gains?

It is likely that a lot of effort will be spent on modifying exhaust positioning throughout the season. At the young drivers? test in Abu Dhabi last year we saw both Williams and Mercedes run exhausts blowing the underside of the rear wing close the car centre line in preparation for the 2012 season.

Engine mapping restrictions

The ability to run different engine maps has been severely curtailed. Now the majority of driver inputs are ‘drive by wire’ ?ǣ in other words, they are processed by the engine control unit. Each driver input will have an ECU map by which input is mapped to output. There are two ways in which the throttle can be manipulated. The first is the pedal ?ǣ this controls how open or closed the throttle is. The second is how the throttle opening position delivers engine torque.

The FIA has attempted to link the pedal position, throttle opening and torque demand. In essence teams are allowed two ‘pedal shaping maps’ ?ǣ one for dry tyres and one for wet/intermediate tyres.

Also, the maximum pedal position must correspond to maximum torque demand of the engine and the regulations also specify how torque demand should increase with change in the pedal position. In addition there are limits on the gradient of the torque demand map and ignition offsets are prohibited under 80% of throttle or 15,000rpm.

Does this mean canny designers will still be able to take advantage of exhaust blown aerodynamics? It will be far harder but after two years of deep research designers have a much greater understanding of exhaust gas flows and so it is likely we’ll continue to see teams experiment with exhaust positioning to eke out every final advantage.

Nose height

Caterham CT01
Caterham's nose: The shape of things to come?

Since the 2009 regulations rewrite there has been a trend for higher noses. This is because a high nose allows maximum airflow under the car which can be shaped by the vanes and feeds the floor ?ǣ which is a major determinant of diffuser performance.

The problem with high noses is that the chance of the car flipping or spearing another car or drive in an accident is higher. The Technical Working Group has therefore been looking for ways to to restrict nose height.

Like all parts of an F1 car the definition of the nose height is complicated. The 2011 regulations allowed the top of the chassis and nose section to be a maximum of 625mm above the reference plane. The boundary height has been lowered to 550mm close to the front axle, which results in an inclined profile to the front wing.

The Caterham CT01, revealed on Wednesday, confirmed suspicions that this would produce an unattractive new breed of cars. Its ‘platypus’ nose hugs the 550mm boundary to allow maximum airflow under the car to feed the floor.

It is likely a typical example of what the front of an F1 car will look like this year. Just fore of the front axle the required 10cm drop is clearly visible. In addition Caterham have chosen to raise the suspension pick-up points in order to create maximum space under the nose.

This solution was common last year but in conjunction with the new nose regulations results in a car with dubious looks. Don’t be surprised if it becomes a common picture up and down the pit lane this year.

Reactive ride height

Kimi Raikkonen, Lotus, Valencia, 2012
Lotus's reactive ride system was banned

Recent weeks have seen much debate over the merits of a reactive ride height system Lotus ran during the young drivers’ test at Abu Dhabi. However on Friday the FIA announced the device was being banned for the coming season.

Ferrari also had plans to run a similar system from the start of the year and Mercedes were believed to be developing the concept as well.

The aim of the device was to stabilise ride height to increase downforce – much like the famed active suspension systems of the earlier nineties and, more recently, the J-damper and mass dampers introduced by McLaren and Renault respectively.

The FIA decided the system contravened article 10.2.3 of the technical regulations which states no adjustment may be made to the suspension system while the car is in motion, as well as some other rules.

F-duct 2.0

Michael Schumacher, Mercedes, Suzuka, 2011
Mercedes experimented with channelling airflow

The F-duct, introduced by McLaren in 2010 and widely copied that year, was banned for the 2011 season. But that hasn’t stopped designers looking into ways to exploit the thinking behind it for other purposes.

The original F-duct was a driver-activated fluid switch that allowed channelled air under the rear wing to create a turbulent flow. This prevented the air from attaching to the underside of the rear wing reducing downforce and also drag.

At the end of the 2011 season Mercedes tested a new front-wing F-duct based on a passive switch – i.e., one without influence from the driver. This is legal under the current regulations and has the potential to open up a new wave of passively-blown systems.

The Mercedes F-duct had an inlet at the front of the nose. Air is routed down the front wing pylons into a long but narrow slot across the breadth of the front wing. This is believed to incorporate a ‘passive switch’ which is dependent on air pressure, which in turn is dictated by how quickly the car is travelling.

There are competing theories about what Mercedes is trying to do with its front wing F-duct. There are two options ?ǣ either keep airflow attached to the wing and increase downforce or to stall the device as was the purpose of the original F-duct.

The placement of the exit slot ?ǣ near the leading edge of the wing – suggests that the most likely intention is to stall the wing rather than assist airflow. If the intent were to keep air attached the slot would probably be placed further back.

The most logical reason to do this is to manage front ride height – the team can reduce it without the risk of the car touching the ground at high speed.


2012 Pirelli F1 tyres
Pirelli have altered their tyres for 2012

One the lessons of 2012 was the significant role that tyres play in F1. At the start of the season, while teams were getting used to the new rubber, we saw the most exciting racing and varied strategy – a view borne out by F1 Fanatics’ race ratings. Towards the end of the season teams had figured out how to set the cars up to optimise tyre performance and we saw less variation in performance.

During the Bridgestone era the focus was on tyre aerodynamic modelling to work out the car/tyre aerodynamic affects. The race tyres were so durable that they never really featured in race strategy.

Pirelli’s entrance into the sport has turned that approach on its head. Teams need to understand what combination of heat and cooling cycles will best cure the rubber for performance. In addition, understanding how to get the most out of a set of tyres is critical to race success.

In 2011 the Pirelli rubber behaved very differently to Bridgestone compounds. The trick with the Bridgestones was to get the tyre up to optimum temperature to create traction through chemical grip. This is less of a feature of the Pirelli tyres where the mechanical grip of the rubber seems to play a larger role.

Pirelli revealed details of changes to its 2012 tyres today. It includes a move towards softer compounds which they hope will recreate some of the early 2011 racing excitement. It will also be worthwhile seeing if the changes in construction alters the way the tyres behave.

As far as improving the quality of racing goes the fundamental problem remains: as teams increase their knowledge of the tyres and improve their tyre simulation techniques, so we are less likely to see the kind of surprises that can make for great races.

Other trends

Felipe Massa, Ferrari, Buddh International Circuit, 2011
Ferrari experimented with tha 2012-style front wing in India

The current generation of rules led teams focus their efforts getting the front wing as close to the ground as possible: whether through Lotus’s banned ride height system or the use of rake to lower the front of the car when it is moving.

The latter not only induces a ground effect but in turn lifts the rear of the car off the ground increasing the volume of air that passes through the diffuser. Provided sufficient air can be fed to the diffuser this, again, will increase downforce. Last year exhaust blown diffusers were a huge help in this endeavour by blowing gasses into the diffuser.

Either way, it isn’t hard to see how critical controlling ride height and rake is. Linked suspension is one way in which teams have tried to add ‘anti-dive’ to their cars. Basically the front and rear suspension systems are linked with a hydraulic line. During braking there is load transfer to the front suspension which can ‘draw’ on the hydraulic link to increase suspension stiffness and prevent excess dive.

This year is also likely to see further conflict around flexible front wings. Red Bull mastered this technology 18 months ago but its complexity has delayed up-take of the technology among its rivals.

Ferrari introduced their version in the last few races of 2011 but with limited success as it suffered from extreme ‘fluttering’. The trick is about composite design and lay-up ?ǣ no doubt all the big teams have been investing heavily to erode Red Bull’s lead.

Evolution or revolution?

Success in F1 today is mostly about incremental change rather than drastic innovation. That is why Red Bull have dominated for the past few years. They have a very strong base car with a deep understanding of its aerodynamic characteristics. Each year Red Bull fine tunes the chassis and suspension striving for ever-tighter component packaging to optimize downforce.

Contrast that approach to McLaren over the past two years. Their 2009 car was two seconds off the pace and the team started with a clean-sheet approach for 2010 around an oversized double diffuser. The diffuser was highly pitch sensitive meaning that the MP4/25 needed very stiff suspension to generate downforce.

The RB6 ?ǣ Red Bull?s challenger at the time ?ǣ was a much more rounded car built on an evolution of the RB5. Last year McLaren went clean-sheet again in designing the MP4-26 with L-shaped sidepods and radical ‘octopus’ exhausts. After struggling in testing the team ditched their exhausts on the eve of the new season and followed Red Bull’s lead.

It takes time and resources to build a complete aerodynamic picture of an F1 car. It isn?t difficult to see how much easier it is to obtain performance if a team is building from a strong concept rather than reinventing the wheel every season.

Given the strength of the RB7 and the stable regulations it is likely the Red Bull RB8 will be an evolution of its championship-winning predecessors. Ferrari, meanwhile, look set to reveal a substantially changed successor to the unsuccessful 150??? Italia.

The view in Woking will likely be that the MP4-26 was fundamentally inferior to the Red Bull, largely because the exhaust blown diffuser was retrofitted to the car and the L-shaped sidepods created aerodynamic compromises with cooling (requiring larger radiators) and airflow around the sidepods sealing the floor. Will they, like Ferrari, go radical in their pursuit of Red Bull?

Testing starts in a few weeks time and that will provide more data points as to who is where. However, it won?t be until Saturday at Melbourne that the true pecking order is revealed.

2012 F1 season preview

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Images ?? Red Bull/Getty images, Red Bull/Getty images, Williams/LAT, Caterham, Lotus F1 Team, Mercedes, Ferrari, Ferrari spa/Ercole Colombo