Mercedes AMG: KERS development

One of Max Mosley’s lasting legacies in F1 was the introduction of his vision of a green initiative in F1. As a result KERS (Kinetic Energy Recovery System) was introduced 2009, as part of a greater package of rule changes to change the face of F1.
KERS is a system which harvests energy under braking and stores it to provide the driver with an extra power boost each lap. A simple technical summary of KERS is here (https://scarbsf1.wordpress.com/2010/10/20/kers-anatomy/ ).
During the 2009 season McLaren were applauded for running Mercedes KERS at every race and it was widely reported as the best KERS in use that year. Along with a few other journalists, I was invited along to Mercedes AMG Powertrains in Brixworth, UK to hear about KERS development since 2009. With Managing Director Thomas Fuhr and Engineering Director Andy Cowell giving a presentation on the range of work Mercedes AMG does with its F1 teams.

Mercedes AMG Powertrains reside on the site that was previously Mercedes Benz High Performance Engines (MBHPE). Now renamed to reflect the wider application of the groups knowledge, both to uses outside F1 and to areas other than engines. Powertrain is a catch all term covering; engine, transmission, electronics and of course KERS Hybrid systems.
The company have built a purpose designed Technology Centre on the site, which historically was the Ilmor engine plant and positioned just a few miles from Cosworth in Northampton. Clearly this area has a rich seam of Engine knowledge.
Formed around three buildings the entire F1 engine and KERS development is carried out on site, only specialist functions such as the casting of the crankcases is carried out off site. Additionally other Mercedes AMG work is carried out here, such as the AMG E-cell car.

KERS 2009
Mercedes AMG (MBHPE as it was known then) developed their first KERS for 2009 in house. At the time McLaren were the primary customer for the system, although Force India and at the last minute Brawn GP were also customer teams that year.  Force India had a chassis prepared to run KERS, but chose not to during the season.  Brawn had a chassis designed before their switch to Mercedes engines, so their car was not designed to accept the Mercedes KERS.

Mercedes AMG: 2009 Battery pack and water cooling radiator

In designing the system, Mercedes AMG had a specific requirement from McLaren. As the effectiveness of KERS was unknown, McLaren didn’t want to compromise the car if KERS was removed. So the system was packaged to fit into a largely conventional car. Whereas other KERS suppliers went for a battery position under the fuel tank, McLaren and Mercedes AMG placed theirs in the right hand sidepod. Low down and far forward, on the floor between the radiator and the side impact structures. The battery pack contains not only the array of individual cells, but also the pump and pipe work for its water cooling circuit. As well as the electronic interfaces for its control and monitoring. The assembly is around 7cm high, 12cm wide and 40cm long. The KBP is probably the single heaviest KERS component. In 2009 this sidepod package was acceptable as the teams were still on Bridgestone tyres and seeking an extremely forward weight distribution. Thus the 5cm higher mounting in the sidepod was offset by its forward placement.

2009 KERS and the batteries sidepod location relative to the engine

Conversely the smaller Power Control Unit (PCU) was placed in a similar location in the other sidepod, ironically the PCU is around the size and shape of road car battery. This left the monocoque uncompromised, aside from the smaller cut out for the MGU in the rear bulkhead.

The 2009 Zytek developed MGU

Then the Motor Generator Unit (MGU) is mounted to the front of the engine.  This device generates and creates the power for the KERS. Its driven from a small set of gears mounted to the front of the crankshaft.  the unit remains with the engien when the car is dismantled and is oil cooled along with the engine.

All of the components are linked both to the SECUs CAN bus and to each other by High Current Cable. The latter taking the DC current between the Batteries and MGU. With this packaging Mercedes AMG quotes the total system weight as 27kg.
Designed and developed by Mercedes AMG, but other partners were involved; the unique battery cells were supplied via A123 and the MGU was partnered with Zytek. Although the power control electronics were solely a Mercedes AMG in house development.
Through the 2009 season both McLaren drivers had a safe and reliable KERS at each race. The system was safe even after crashes and was fault free despite rain soaked races. Safety was designed in from the outset, all electrics were double insulated. Teams can also measure damage to the unit via accelerometers and insulation sensors, so any impact or incidental damage can be monitored and the car retired if the need arises. Additionally each cell in the battery has its temperature monitored. KERS batteries are sensitive to high and low temperatures, each cell needing to operate in a specific thermal window. Too low and the unit is inefficient and too hot and there’s the danger of explosion.
Perhaps the only criticism was the sidepod battery mounting, despite several incidents, this never put any one in danger, so this never proved to be an unsafe installation.

KERS 2011

2011_Mercedes_AMG_engine

For a variety of non technical reasons KERS was agreed not to be raced from 2010 until the planned 2013 rules. However this plan changed, but not before Mercedes AMG had made new strategic plans around KERS.
Mercedes AMG set out a longer term strategy to work on research for KERS in preparation for 2013, as well as working with AMG to develop the road car based E-cell technology.
(Link Mercedes AMG E-Cell chassis  )
This changed when the plans for the 2013 engine were pushed back to 2014 and KERS was agreed to be reintroduced for 2011. Thus the 2013 development plans had to rebased and deliver a refined version of the 2009 KERS for 2011. Moreover there were now three teams to be supplied with KERS. There was no Christmas for Mercedes AMG staff 2010!
As a result of the research work carried out after 2009, Mercedes AMG now solely design, develop and produce the entire KERS package, aside from the Battery cells. So now the MGU is a wholly Mercedes AMG part.

The MGU fits to the front of the engine and driven from a small set of gears

With KERS effectiveness proven in 2009, it was possible to have the cars designed around it, rather than it be an optional fitment. So the packaging was revised and the entire system integrated into just two units. The MGU remains attached to the front of the engine, still driven off a spur gear on the nose of the crankshaft. While the KBP and PCU are now integrated into a much smaller single package and fitted under the fuel tank. The unit bolts up inside a moulded recess under the monocoque, the unit being attached using four vibration mounts, and then a closing panel and the cars floor\plank are fitted under it.

The 2009 battery pack (yellow) is now integrated with the power electronics (not shown) in a single unit under the fuel tank (red).

It’s this integration of the batteries and power electronics that has has really slimmed the 2011 system down. Mercedes AMG now quote 24kg the entire KERS, much of the 3kg weight loss being down to the reduction in the heavy power cabling between these units.
Not only is the packaging better, but the systems life and efficiency is too. Round trip efficiency stands at a stated 80%, which is the amount of power reapplied to the engine via the MGU after it has been harvested and stored. Improvements in efficiency being in both the charge and discharge phases.
Battery pack life was extended to as much as 10,000km, several times the 2009 predictions that batteries would need replacing every two races (2,400km). Over this period, the cells do not tend to degrade, as the team manage the unit’s condition (‘State of Charge’ & temperature) throughout the GP weekend to maintain their operational efficiency.
The 80hp boost KERS provides, stresses the engine. This was well known back in 2009, but for 2011 along with DRS the car can be several hundred revs higher than the usual EOS (end of straight) revs. Mercedes AMG quoted 15-25% more stress for a KERS and DRS aided lap, this needing to be taken into account when the team monitor the engines duty cycle, thus deciding when to replace it. Mercedes conducted additional dyno development of the engine being kept on the rev limiter to fully understand and counter this problem. This work paid benefits; Hamilton ran many laps at Monza bouncing off the rev limiter along the main straight, while chasing Vettel.

KERS in use
Although the max 60KW (~80hp) output can be reduced from the steering wheel, its normal for the driver to use the full 80hp boost each time they engage the KERS boost. With a reliable KERS, the driver will use the full 6s boost on every lap. Media reports suggest Red Bulls iteration of the Renault KERS does not use this full 60kw. Instead something like 44kw, providing less of a boost, but allowing smaller batteries to be used. The loss in boost being offset by the overall benefit in car packaging.
The driver engages a KERS boost either via a paddle or button on the steering wheel, or by the throttle pedal. The latter idea being a 2009 BMW Sauber development, where the driver pushes the pedal beyond its usual maximum travel to engage KERS. Nick Heidfeld brought this idea to Renault in 2011 and the over-extended pedal idea has also been used for DRS too.
Once the driver is no longer traction limited out of a turn, they can engage KERS. Usually a few small 1-2s boosts out of critical turns provides the ideal lap time. It’s the driver who has to control the duration of the boost, by whichever control. As with gear shift the drivers can be uncannily accurate in their apportioning of the boost around the lap. It’s suggested that the 2009 Ferrari system apportioned the duration of the KERS boost via a GPS map, the driver simply presses the button and the electronics gives them the predetermined amount of boost. This solution came as surprise to Andy Cowell, so one wonders if this is legal or perhaps if the report is true.
From on board shots, we’ve seen the steering wheel has an array of LEDs or numerical displays to show the driver the boost remaining for that lap. The SECU will have control code written to prevent overuse of KERS around a lap.
Typically the battery will hold more charge than a laps worth of harvesting\discharge. So that any unexpected incidents do not leave the driver without their 6s of boost.
In use KERS can be used in several different ways. When lapping alone KERS typically gains 0.45s per lap, although this varies slightly by track. Along with DRS is can boost top speed by 12kmh. As explained the driver uses a pre-agreed amount of boost, decided from simulation work done at the factory before the race. So the planned strategy of KERS usage will be used in practice, qualifying and in parts of the race. However in the race the driver can use KERS tactically to gain an advantage. Drivers are able to use more a KERS boost to either overtake or defend a position. One feature of 2011 along with the Pirelli tyres being in different condition during the race, was the driver’s freedom to alter their racing line and use their grip and KERS to tackle their rivals.

KERS future
KERS continues in its current guise for another two years, then for 2014 along with all new engine regulations there will be a new format KERS. Energy recovery will be from different sources, so the overriding term for the hybrid technology on the car will simply be ERS (Energy Recovery Systems). However KERS will still exist, harvesting energy from braking, but will have a greater allowance for energy stored and reapplied. But, there will also be TERS (Thermal Energy Recovery), which a MGU harvesting energy from the turbocharger. Overall ERS will provide a third of the engines power for some 30s of the lap. No longer will the driver press a button for their KERS boost, it will be integrated in their demand for power from the throttle pedal. The electronics will be constantly managing the Powertrains energy, harvesting and applying energy based on whether the driver is on or off the throttle. In 2014 Powertrains and ERS is set to become very complicated.

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Abu Dhabi Test: Red Bull Aero Rake

Red Bull started the Abu Dhabi Young Drivers test with a mass of aero testing equipment fitted to the RB7. Although the test is supposed to be to assess young drivers, this is the first open test since the season started and teams make use of this time to gather data from the car. In Red Bulls case this was a repeat of tests from last year, where the front wing ride height and wake is being measured by a range of sensors.

Pictures via F1Talks.pl & SuttonImages.com
Airflow around the front tyre is critical with the post-2009 wide front wings. The ever more complex front wing endplates direct the airflow around the tyre. This effect varies greatly with front wing ride height, so that when the wing flexes down under load at speed, the airflow changes. I have learnt from F1 aerodynamicists that the effect of the endplate on flow around the wheel as the wing flexes down, is perhaps more important than downforce gained the wing being closer to the ground. So the Red Bull and also Ferrari tests are critical to understand how the airflow passes around the tyres with varying wing ride height.
Clearly the gains from flexible front wings will be an ever greater performance factor next year. Even though the FIA rules amended for 2011 were even more stringent than in 2010.

In Red Bulls the case the set up consists of three main elements; the aero rake, ride height sensors and the cables holding the front wing.

Wing mounting cables

Wing cables & Nose hump – Picture via F1Talks.pl & SuttonImages.com

Ride Height Sensors

Ride Height Sensor – Picture via F1Talks.pl & SuttonImages.com

Ride height Sensors – Picture via F1Talks.pl & SuttonImages.com

Aero Rake

Rake detail – Picture via F1Talks.pl & SuttonImages.com

My interpretation of how the rig works is: the wing is allowed to deflect at speed to a specific height, this is controlled by the cables from the hump on the nose. By limiting droop, a number of wing ride height settings can be assessed during the runs. Laser ride height sensors both in the centre and at the front and rear of the endplate will confirm the actual ride height and wing angle being tested. Then the rake will take measurements of the airflow. The driver will then run at a fixed speed along the straight, keeping a consistent speed will ensure the data is consistent and the amount of wing flex can be predicted for each run.
This will create an aero map of flow across the wing and with the wing at different attitudes. The data from the tests will be used to confirm CFD\Wind tunnel results and direct the team in deciding how the wing should flex in 2012.

We can now look in detail how the rig is made and how it works.

Cables holding the front wing


During some runs we saw the cables lying loose between the wing and the hump. Which confirms they are cables and not solid rods, as with the rake mountings. Being cables they could not be for measuring wing position, as not being stiff, they would not be accurate enough. With the size of the nose hump and the other equipment to measure ride height, I now believe they are to control the droop of the front wing. Perhaps the test wing is more flexible than the usual race wing in order to achieve more attitudes under load. Its possible the hump contains hydraulics to adjust the droop of the wing to different attitudes during each run. The 2009 Red Bull used hydraulics in the nose to control the then legal adjustable front wing flap, so it’s a proven approach to fit more hydraulics into the nose cone. Being able to alter wing attitude on the move would greatly improve the amount of data gathered from each run. With there being two cables for each wing, one mounted on the main plane and the second on the flap, the wing could be controlled not only in droop but also the angle of attack. So that the wing could reproduce different beam and torsional stiffness of a future wing.

Ride Height sensors


We have seen laser ride height sensors fitted to cars through Friday practices and extra units fitted for testing. For the front wing rig Red Bull ran five ride height sensors on the wing. The central unit is fitted to the neutral centre section of wing. This would measure true wing ride height, as the centre section is relatively stiff and is not part of the deflecting structure of the wing. Then two ride height sensors are fitted to front to the front and rear of the endplate. These would measure the ride height of the wing tips. Using the centre ride height sensor as a base line provides the amount the wing tip is deflecting. Just as with the double cable arrangement supporting the wing, the two endplate ride height sensors would measure any change in angle of attack, the delta between the front and rear sensors showing the wings angle of attack.

Aero Rake


With the wings attitude controlled and measured by the cables and sensors, the wake of the wing is then measured by the aero rake. This is an array of sensors measuring air speed, velocity and perhaps even direction. Two rows of rakes are employed and these are securely mounted to blisters on the nose cone. Just as with the wing mounting cables these struts may be attached to hydraulics to raise the rake over a range of positions, to map a wider area behind the wing. A slightly messy part of the mounting system if the bundle of cables exiting the rake and passing up into the nose cone to be attached to the cars telemetry system.

Red Bull: Splitter scandal 2011?

Photo Copyright: Wolfgang Wilhelm/ Auto Motor und Sport

Following on from the Monza footage of the Mark Webbers Red Bull being lifted on a crane over a spectator area (http://vimeo.com/29538310), German Magazine ‘Auto Motor und Sport’ (AMuS) reported that the legality of the front splitter could once again be called into question. The footage shows the wear marks on the skid block (plank) under the car, with the wear focussed across the protruding section of splitter.

Last year Red Bull as well as other teams were suspected of having a flexible splitter. In order to run lower front ride heights to gain more front wing performance, the splitter gets in the way. Making it bend upwards, allows the crucial nose-down raked attitude required to exploit the current rules. So last year the splitter test was made more severe and also included tests to ensure the splitter couldn’t twist to avoid wear.

AMuS suggests the wear on the splitter is limited to this front section of the plank, the splitter ‘bending’ to spread the wear and avoid infringing the rules on post-race plank thickness. (http://www.auto-motor-und-sport.de/formel-1/f1-technik-exklusiv-red-bull-unterboden-illegal-4043971.html).  Wear is evident on the picture (above) of Mark Webbers cars from Monza.  This wear pattern, is backed up by a view of Vettels RB7 being craned off the track at Suzuka (not shown here), which also suggests the wear is focussed to the front 50cm of plank and not merely the leading edge where the FIA measure wear.

When raked, the splitter should wear in a taper from the leading edge

Wear only at the front of the plank is understandable; such is the nose-down attitude of the Red Bull, very little of the rest of the plank is within reach of the ground. But one would expect the wear to take a wedge shape section out of the plank, at an angle similar to the cars angle of rake. Instead the wear is focussed evenly across this front section of floor, indeed this picture suggesting the greater wear is at around 50cm back front the tip of the block.

Looking at the underside of other cars that had been craned off the track at Monza, their wear is across a greater section of plank, with no highspots of wear midway along their length.

Working how Red Bulls unusual wear pattern is created is a conundrum. The wear could simply be the result of going across kerbs during the accidents and doesn’t occur during normal running. Or the wear could be a literal interpretation of the rules, the leading edge meets the FIA vertical load test, but the splitter articulates further back along its length, to present the splitter at a flatter angle to the track to reduce wear and provide a lower front ride height. Such a set up would meet the wording of the rule 3.17.5 on the deflection and construction of the splitter. As the articulation may be at the point where the tail of the splitter meets the chassis and hence not directly affected by the FIA test and inspection of the leading edge of the splitter.

3.17.5 Bodywork may deflect no more than 5mm vertically when a 2000N load is applied vertically to it at three different points which lie on the car centre line and 100mm either side of it. Each of these loads will be applied in an upward direction at a point 380mm rearward of the front wheel centre line using a 50mm diameter ram in the two outer locations and a 70mm diameter ram on the car centre line. Stays or structures between the front of the bodywork lying on the reference plane and the survival cell may be present for this test, provided they are completely rigid and have no system or mechanism which allows non-linear deflection during any part of the test.
Furthermore, the bodywork being tested in this area may not include any component which is capable of allowing more than the permitted amount of deflection under the test load (including any linear deflection above the test load), such components could include, but are not limited to :
a) Joints, bearings pivots or any other form of articulation.
b) Dampers, hydraulics or any form of time dependent component or structure.
c) Buckling members or any component or design which may have, or is suspected of having, any non-linear characteristics.
d) Any parts which may systematically or routinely exhibit permanent deformation.

Regardless, the Red Bull passes the current stringent FIA scrutineering tests and with the precedent set last year, the car is therefore legal.

No further discussions on the subject appeared over the Suzuka weekend, so this doesn’t appear to be an issue. Again it’s left up to the other teams, to find a way to obtain the raked attitude to gain front wing performance, without excessive plank wear.

Thanks to Auto Motor und Sport for the permission to use their photogaphs with in this post.

Red Bull – Singapore Front Wing Upgrades


At this late stage in the season it seems Red Bull are the main team bringing upgrades, in recent races only Lotus, Virgin and Renault have notable developments. Clearly the imagination of Adrian Newey and Peter Promodrou along with the Aero Dept in Milton Keynes are still bringing new ideas to the table.
Although some elements have been seen tested at earlier race weekends, this is the first proper appearance of the new assembly. The wing now features a twisted main plane section and a revised cascade.

The main plane is no longer near horizontal meeting the FIA specification centre section of wing. Instead the wing curls up and intersects the central span at a near 90-degrees. I suspect this shape is to create a vortex along the Y250 axis, which a key area for creating the correct airflow conditions ahead of the leading edge of the floor. With the aim of creating more downforce from the floor and diffuser.

For the streets of Singapore, the team need a high downforce set up, thus the cascade which gained the McLaren style “r” vane in Monza (https://scarbsf1.wordpress.com/2011/09/10/red-bulls-monza-front-wing/ ), has now been extended with a large downforce producing section. Unlike the kink in the main plane, the inner end of this cascade has an elliptical section which aim to reduce vortices created at the wing tip, sending a cleaner wake downstream.

Red Bull – Monza Diffuser Analysis


Red Bull appeared in Monza was a further development of their diffuser. Changes largely appeared to be focussed on the treatment of the trailing edge of the bodywork. For Monza the diffuser gained a flap around almost the entire periphery of the trailing edge.

Highlighted in Yellow, RBR had a flap spanning around most of the diffusers trailing edge

This flap has been used above the diffuser since the start of the season, but the flap has been narrower, being only fitted in-between the rear wing endplates. As explained in my analysis of the floor as seen at Monaco (https://scarbsf1.wordpress.com/2011/06/08/red-bull-monaco-floor-analysis/ ).

Many pictures were taken of the flap now extending around the sides of the diffuser, which I tweeted about during the Monza GP weekend. But it was the fan video taken during the race, as Mark Webbers stricken RB7 was craned off the track that has shown the floor in greater detail. The video posted on Youtube.com by atomik153 and seen here (http://youtu.be/swoomrzECdM ). This clearly shows the floor from about 3m 40s into the clip. Obviously this must have been unpleasant for Red Bull as the floor is so clearly visible, I know that the other teams have seen this clip. Many fans having seen the detail at the back of the diffuser and suggested the slot created around the diffuser was some form of double diffuser or cooling outlet. While the pictures might suggest this, the slot is merely the gap between the aerofoil shaped flap and the diffuser.  This following illustration shows how the flap is actualy shaped.  There are two parts; the new curved side sections and the pre-existing top sections.

When exploded, you can appreciate how the new bodywork forms a flap around the diffuser

Diffuser trailing edge theory

Few ideas in F1 are new, merely older ideas reinterpreted and expanded upon. This flap is not a new idea, its merely an extension of the gurneys teams have been fitted to the trailing edge of downforce producing devices since the sixties. Gurneys have been added to the end of a diffuser to aid the low-pressure region above and behind the diffuser. This practice has been increasingly important with the limit on diffuser height and other rules banning supplementary channels such as the double diffuser. As far back as the late nineties teams replaced this gurney with an aerofoil section flap. Notably Arrows and latterly Super Aguri used flaps placed above the diffusers trailing edge.

The need for this sort of treatment at the back of the diffuser might at first be confusing. A diffuser is a part of the underfloor, by accelerating air under the floor, low pressure is created and thus downforce is generated. With so many restrictions on the geometry of the floor and diffuser, teams cannot simply enlarge the diffuser for more performance. So they are forced into working different areas of the device harder for the same effect. One area is maximise pressure ahead of the floors leading edge, the other is the lower the pressure behind the trailing edge. This helps flow out of the diffuser, to maintain mass flow under the floor. Although the rules limit the height of the diffuser, this is only the height below the tunnels to the reference plane. Teams have a small amount of space above the diffuser for bodywork and the common gurney fits into the area. Gurneys work by creating a contra rotating flow behind the upright section, this creates low pressure and helps pull airflow from beneath the wing. On a diffuser this has the same effect as a slightly higher diffuser exit.

A gurney creates low pressure by the contra rotating vortcies behind the gurney

The gurney can work above the diffuser, as teams have been paying so much attention to getting high pressure air over the top of the diffuser. This airflow is used to drive the vortices spiralling behind the gurney flap. The better the airflow over the diffuser to the gurney the more effective it can be.   However Gurneys cannot be infinitely increased in size and still maintain their effect. As the gurney gets too large the dual vortices break up and the low pressure effect is lost. Many teams have found this limit this year and have moved to the next solution which is a perforated gurney.

A perforated gurney can be larger as it's offset from the diffuser allowing airflow to pass under the gurney

This is a similar vertical device fitted to the diffusers trailing edge, but there is a gap between the bottom of the gurney and the diffuser. Airflows through this gap to create the distinctive contra rotating airflow behind the gurney. Again this has the same effect as creating a larger diffuser exit and hence creates more downforce.

An aeroil shaped flap can be larger and more efficient than a Gurney

While the gurney is a relatively blunt solution, Such is the quality of the airflow over the diffuser now that teams are able to fit a more conventional aerofoil shaped flap above the diffuser for a similar effect. Without the contra rotating flow of the gurney this solution can be scaled up, as long as the flow to the flap is maintained. Many teams have this solution fitted along the top edge of the diffuser. Although Red Bull are the only teams to have fitted to the side of the diffusers trailing edge. Increasingly teams are seeing the diffuser exit as a 3D shape, the diffuser not only diverges vertically at the exit , but also laterally. No doubt exhaust blowing does allow some of these devices to be effective.

In Detail: The flap on Red Bulls diffuser

We can expect its use to be expanded for next year with larger flaps above the diffuser and flaps around the entire periphery of the diffuser. A long with Rake this will be a critical design feature for 2012, as a result sidepod design will become one of the critical factors in aero design, making sure the top of the diffuser is fed with good airflow. As so few other areas provide potential gains for improving aero efficiency.

Other notes on the Red Bull Floor

Fences

Red Bull fit three fences in each side of the diffuser, these prevent different pressures regions migrating from one side of the diffuser to another. They help maintain downforce and sensitivity. Its interesting to note the fences are not triangular in side profile, I.e. that they don’t meet at the kick line between the floor and diffuser, instead they start a few centimeters behind the axle line with a rounded vertical leading edge.

Starter Motor Hole


As mentioned in the Monaco RBR floor analysis the starter motor hole is blown by ducts in the upper side of the floor. This injects some energy into the flow in the middle of the diffuser. This so called boat-tail section is where the steeped underbody merged with the higher step plane. With the lower centre section and plank, getting airflow into the area is difficult and separation can easily occur if the angle of the floor is too steep. Having the starter motor hole blown helps maintain airflow in this area.

Metal Floor

Exhaust Blown Diffuser Flow

Red Bulls Monza Front wing

Red Bull have appeared at Monza wit the expected specialist low drag wings. However their front wing sports a new detail inspired by McLaren. The “r” shaped inner cascade, has been a feature of McLaren since late last year. This feature has also been used by Sauber.
The horizontal section will probably directly produce some downforce while the vertical sections is more likely to act like a turning vane to direct the general airflow outwards.
For this race Red Bull use a simpler three element wing, with the trailing edge of the flap cut back to create a shorter chord for less downforce.

Book Review: Haynes Red Bull Racing F1 Car

When Red Bull Racing launched their new car for 2011, the event was marked by a very special press pack. The pack was formatted in the style of the well-known Haynes maintenance manuals (PDF). This in itself this was a great book, but almost unnoticed within its pages was the intended publishing of a complete Haynes style workshop manual on the RB6 car.
Now some six months later the Haynes Red Bull Racing F1 Car Owners Workshop Manual (RB6 2010) has been published. As its rare a Technical F1 book is published, not least one with insight into such a current car, I’ve decided to review the book in detail.

Summary
At 180 pages long the book has enough space to cover quite a wide range of topics and it does so. Starting with a background to the team, moving on to the cars technology, to overviews of its design and operation. With its familiar graphical style and hardback format it certainly gives the feel of a proper workshop manual. However this is somewhat skin deep and the pages within, soon revert to a more typical book on F1, although some flashes of the Haynes style do remain.

Steve Rendle is credited as the writer of the book and Red Bull Racing themselves have allowed close up photography of the car and its parts, as well as providing a lot of CAD images.
But clearly a lot of editing has been carried out by Red Bull Racing and the book falls short of its presentation as a manual for the RB6. Despite its confusing title, the book is probably better described as a summary of contemporary F1 technology from the past 3 years.
As the last in depth technical F1 book was the heavy weight title from Peter Wright showcasing Ferraris F1 technology from 2000, this remains a useful source of recent F1 technology.
This places the books target audience, somewhere between the complete novice and those already of a more technical mindset.

Anatomy

With forewords by Christian Horner and Adrian Newey, the opening 21 pages are a background to the team and detail of the 2010 season that brought RBR the championships. Then starts the core 100 page chapter on the cars anatomy, which opens with a pseudo cutaway of the car showing a CAD rendering of its internals.

Firstly the monocoques design and manufacture is covered, with images of the tubs moulds being laid up and CAD images of the RB4 (2008) chassis and its fuel tank location. Although little is made of the fuel tank design.
Moving on to aerodynamics, the text takes a simplistic approach to explaining aero, but there is an interesting illustration of the cars downforce distribution front to rear. This does highlight the downforce created by the wings and diffuser, but also the kick in downforce at the leading edge of the floor, but this is not adequately explained in the text. Mention is made of the front wing and the flexing that RBR deny, this is explained with a simple illustration showing the deflection test. The driver adjustable front flap, which was legal during 2009-2010 seasons, is explained, in particular that the wing was hydraulically actuated. When I understood that in 2009, only Toyota used a hydraulic mechanism over the electric motor system used by all other teams. In trying to explain the nose cone, the text and an illustration show a high nose and low nose configuration, but does not remark why one is beneficial over the other.

This section also covers very brief summaries of bargeboards, sidepods and the floor. Some nice close up photos of these parts included, but again with little explanation. An illustration at this point highlights the other FIA deflection test altered in 2010, which was aimed at Red Bulls alleged flexing T-Tray splitter. In this section the text cites Ferraris sprung floor of 2007, but not the allegation that RBR’s was flexing in 2010. A further simple graphic illustrates the venturi effect of the floor and diffuser, and then the text goes into simple explanations of both the double diffuser and the exhaust blown diffuser.
Having been one of the technical innovations of 2010 and since banned, the book is able to cover the F-Duct is some detail. A complete CAD render of the ducting is provided on page 53; this shows an additional inlet to the drivers control duct that was never visible on the car. This extra duct served the same function as the nose mounted scoop on the McLaren that introduced the F-Duct to F1.
Thus with aerodynamics covered in some 23 pages, the text moves onto suspension and the expectation of detail on the RB5-6’s trademark pullrod rear suspension. After a summary of the purpose of an F1 cars suspension, Pages 58-59 have some fantastic CAD renderings of front suspension, uprights and hub layouts. However the rear suspension rendering stops short at the pull rod and no rocker, spring, damper layouts are detailed. Hardly a secret item, so lacking this detail is let down for a book announced as an RB6 workshop manual. A lesser point, but also highlighting the censorship of some fairly key technical designs, was the lack of any reference to Inerters (Inertia or J-Dampers), The suspension rendering simply pointing to the inerter and calls it the ‘heave spring’, while naming the actual heave spring damper as simply another ‘damper’. Inerters have been in F1 since 2006, predating Renault’s mass damper. Their design and purpose is well documented and shouldn’t be considered something that needs censoring. It’s also this section that fails to showcase the RB5-6 gearbox case. Instead using a pushrod suspended RB4 (2008) gearbox, albeit one made in carbon fibre.
The steering column, rack and track rods are similarly illustrated with CAD images. This usefully shows the articulation in the column, but little of the hydraulic power assistance mechanism. Page 67 starts the section on brakes, again fantastic CAD images supply the visual reference for the upright, brake caliper and brake duct design. As well as a schematic of the brake pedal, master cylinder and brake line layout of the entire car. A nod to more typical Haynes manuals shows the removal of the brake caliper and measure of the Carbon disc\pad. A further CAD image shows the brake bias arrangement with both the pivot at the pedal and the ratchet control in the cockpit for the driver to alter bias.
Although not a RBR component the Renault engine is covered in the next Chapter. An overview of the complex engine rules regarding the design and the specification freeze kicks off this section and cites the tolerances and compression ratio for a typical F1 engine. Pneumatic valves, for along time an F1-only technology are explained, but even I failed to understand the schematic illustrating these on page 77. Also covered in the engine section is some more detail on the fuel, oil and cooling systems. With useful specifics, like capacity of the oil system at 4 litres and water coolant at 8 litres. Again some nice CAD images illustrate the radiators within the sidepod. Many sections have a yellow highlighted feature column; this sections feature is on the engine start up procedure, one of the mundane, but rarely talked about processes around an F1 car (other features are on the shark fin and brake wear). As KERS wasn’t used up until 2011, this topic is skipped through with a just a short explanation of the system.

Moving rearward to the transmission system, the old RB4 gearbox makes a reappearance. Again this disappoints, as some quite common F1 technology does not get covered. Page88 shows some close up photos of a gear cluster, but this is not a seamless shift gearbox. In fact seamless shift isn’t mentioned, even though it made its RBR debut in 2008, the year of the gearbox showcased in the book. I know many will highlight that this might be a secret technology. But most teams sport a dual gear selector barrel, each selector looking after alternate gears to provide the rapid shift required to be competitive in F1. So I think this is another technology that could be explained but hasn’t been.
Tyres, Wheel and Wheel nuts get a short section, before the text moves onto electronics. A large part of the electronic system on a current F1 car is now standardised by the Single ECU (SECU) and the peripherals that are designed to support it. So this section is unusually detailed in pointing out the hardware and where it’s fitted to the car. From the tiny battery to the critical SECU itself. Other electronic systems are briefly described from the Radio, drivers drink system to the rain light.
Of critical importance to the modern F1 car are hydraulics, which are detailed on p105. As with the other sections, CAD images and some photos of the items themselves explain the hydraulic system, although there isn’t a complete overview of how it all fits together.
Rounding off the anatomy chapter is the section of safety items and the cockpit. The steering wheel and pedals are well illustrated with CAD drawings and keys to the buttons on the wheel itself and on the switch panel inside the cockpit.

While I have pointed that the hardware shown in the anatomy chapter isn’t necessarily of the RB6, what is on show is obviously genuine and recent RBR. So for those not so familiar with the cars constituent parts, there isn’t a better source of this available in print today. Even web resources will fail to have such a comprehensive breakdown of an F1 car.

The Designers view

Moving away from the Haynes format of a workshop manual, the book then moves into a chapter on the cars design, with comments from Adrian Newey. It details the Design Team structure and some of the key individuals are listed. The text then covers the key design parameters; centre of the gravity and the centre of pressure (downforce). Plus the design solutions used to understand them; CFD, Wind Tunnels and other simulation techniques. Each being briefly covered, before similar short sections on testing and development close this chapter.
Although the text makes reference to creating ‘the package’, something Newey excels at. This section doesn’t provide the insight into the overall design philosophy, which one might have hoped for.

The Race Engineers view
Where as the Designers view chapter was limited, the race Engineers section was a little more insightful into the rarely talked about discipline of getting the car to perform on track. The process of setting up the car is covered; from the understanding of the data, to the set up variables that the race engineer can tune; suspension, aero, ballast, gearing brakes and even engine. Usefully the grand prix weekend is broken down onto the key events from scrutineering, to running the car and the post race debrief. Feature columns in this chapter include; Vettels pre race preparation and the countdown to the race start.

The Drivers view
Ending the book is an interview style chapter on the driver’s time in the car, mainly the driver’s perspective from within the cockpit when driving the car on the limit and the mindset for a qualifying lap. A simplistic telemetry trace of a lap around Silverstone is illustrated, although there is little written to explain the traces (brakes, speed and gear), this is accompanied by Mark Webbers breakdown of a lap around the new Silverstone circuit.

In conclusion
When I first got this book, I was constantly asked if it was worth the purchase or if I’d recommend it. If my review is critical at points, it’s mainly because some technology that could have been covered wasn’t. Or, that the content falls short of the books title suggesting it was a manual for the RB6.
Those points aside, I have learnt things from this book. Like details of the F-duct system, the Front Flap Adjuster and a wealth of smaller facts. There isn’t a better book on the contemporary F1 car. In particular the CAD drawings and close-up photos, just simply aren’t in the public domain. From the pictures we got over the race weekends, we never get to see half the hardware and design work that’s pictured in this book. So I’ll keep this book on hand for reference for several seasons to come.

Overall I’d recommend this book to anyone with a technical interest in F1.

Many thanks to Haynes Publishing who have allowed me to use their Images and PDFs to illustrate this article

This book is available from Haynes