Mercedes AMG’s W06-Hybrid dominated the season this year. I’ve been lucky enough to get close to it and find out lots about its design and details. So I’ve put together a comprehensive ‘walk-around’ the car, from my camera phone pictures taking whilst being in the pit lane over race weekends.
Merc ran with a single spec nose, with two slightly different chin set ups. Its nose used a streamlined tip, which lead on to a narrow shaped nose, rather than the wide wedge shaped of its rivals. This appeared to open up airflow around the sides to the al the Y250 aero devices.
The upper shape of the nose was all structural, but the under ‘chin’ was a bonded on section. This stops sort of the rest of the nose, which lead this to being mistaken for an airflow exit, but in fact the opening was closed up with a ‘beak’ like extension from the bottom of the front bulkhead. This extension housed the ground speed laser which viewed the track through a transparent window made in to the beak.
Mercedes were also one of the teams to exploit the stalk mounted camera pods. This raised the pods obstruction much higher up to prevent the pod’s wake affecting bodywork downstream. It also usefully moved the cameras point-of-view above the front wing flaps.
The season as started with a version of the outswept wing used in late 2014, already a complex six element set up, with the separate sections curling around to form a slotted footplate. The inboard transition to the neutral centre section was only lightly worked for aY250 effect. Outboard the cascades were a delta shaped 2-element winglet and “r” vane. With the endplate vane gaining both inner and outer strakes.
The wing was permanently fitted with small pods on the cascade wing for tyre temperature measurement. Also the wing was instrumented with pressure taps to allow the team to detect if the wing is damage of reduced in performance during the race.
Then the big update wing came in with the aggressively arched outer step section. Whereas before the wings leading edge was flat and arched gently up before curling around, the new design has a distinctly square shaped arch, with sharp transitions from wing to arched section.
With the new wing, the two rear flaps became the adjustable section with the simple screw adjustment system, the mechanics used a cordless power drill preset with the number of turns required to adjust the wing at pit stops. Also for the race, the wing was routinely sprayed with a silicone coating, the non-stick effect prevented debris and tyre marbles clogging the wing’s numerous slot gaps.
Later in the year the wings undersurface gained a serrated trailing edge, this being fitted to the last slot gap, the turbulent effect of the serrations helping keep the airflow attached under the wing.
Along with the transient of the front wing from curved outer spans to the neutral centre section, the W06 had an array of complex and trend leading aero devices along the Y250 axis. This is a line along the cars flank, where aero devices can be placed, beyond the 250mm from the cars centerline, shaped bodywork is banned, so parts within this area are critical for shaping airflow around the car, pushing the front tyre wake awake from the rear bodywork.
Y250 devices start with the front turning vanes, these ended up for element vanes each connected to a wide curved footplate. These were a constant source of development, with numerous flow viz runs being undertaken in free practice to check the flow in this complex area. Behind this was the ‘Bat’ wing, an upturned wing, creating lift, but also critically a vortex along the Y250 axis. Below this were small vanes above the T-Tray splitter. The splitters side vane was also placed unusually rearward, some 100mm or more behind where most teams place their side vane.
Its main bargeboards were conventional enough, but they partly obscured four small vortex generators, the down swept fins directed airflow around the sidepod’s undercut. The bargeboards, were aided by a smaller turning vane on the floor and the lower section of the vertical pod vane. Tucked away on the floor behind the turning vane was as a small flick, also helping swirl the airflow around the sidepod’s. This area led out to the floor’s two edge flicks, with the forward upturned floor section gaining a small flap above it.
Around the sidepod inlet’s perimeter, Merc added a vertical vane, which split to wrap around the sidepod, with a further transition into a horizontal vane mounted much closer to the sidepod’s top surface. Both the mirror mounting and the vane around further aided airflow over the sidepod’s top surface.
There’s three aspects to the front suspension; its external geometry, the inboard compliance effects and the aero effect of the outboard elements.
As far as geometry, it’s clear Mercedes hasn’t gone as far as others for extreme aero or geometric effect. Taking the placement of the fixed size and height front bulkhead, the upper wishbones are mounted lower with anti-dive angle built into them. While the lower wishbones appear to follow the same thinking, albeit with the 2014 innovation of merging the wishbone legs into one cross section. The pushrods are the common offset pushrod-on-upright set up, reaching to the inboard mounted rockers, hidden under a removable body panel.
Inboard Mercedes retained its class leading Mechanical and Hydraulic suspension set up. Albeit FRIC was banned mid-season 2014, the car still sported both a coil sprung heave damper and a gas (Hydraulic) heave damper. The coil sprung unit is sat in the open hatch visible through the top of the chassis, with its large diameter hollow titanium spring. Inside the footwell area, the hydraulic element remained hidden. But hydraulic bleeding\pressurising kit during the cars pre-GP build process in the garage proved hydraulics were still at play. This complex set up allowed the Mercedes to have almost no visible dive under braking, but plenty of suspension movement in roll and over kerbs. Conventional torsion bars and an anti-roll bar are in play, with no obvious diagonal links.
For the last two races, the team played with a new front heave set up, with the coil spring elements switched in place of a hydraulic unit, in-line with bump stops and a inerter. Presumably the coil spring has been wholly replaced with a hydraulic spring set up, most likely mounted remotely within the sidepod.
Aerodynamically the front suspension extends the theme from last year, with the conjoined lower wishbone legs now having the steering track rod placed in the same axis. So the steering rack has been lowered and the track rod is kinked, such that it drops from the racks axis to have the bulk of the arm almost in-line with the lower wishbone. Although in fact the track rod sits slight above the wishbone, to help the flatten the upwash from the front wing.
Another interesting 2015 development on the steering is the Aluminium steering rack body is now wrapped in carbon fibre to stiffen the assembly. Once assembled the steering rack, hydraulic unions and brake reservoirs are protected by a carbon fibre cover over the front bulkhead.
Brake were a major topic at Mercedes during the year, after the failures of the Brembo material last year, the Carbone Industrie material continued to be run on the front, while Brembo disc\pads were still an option for the underworked rear brakes. Both axles continued to run Brembo Calipers, with the elaborate rear bridge structure, with a section spanning either side of the caliper in between each pair of caliper pistons. Then a thinner radial bridge running in between the disc and the pads, allowing hot air to escape from the exposed disc and pads.
I was told the team at towards the limit of braking power, where increased braking performance is limited not by downforce or tyre grip, but by the ability of the caliper\disc to provide greater retardation. Thus feel was a critical factor, this affected by the pedal, master cylinder set up as well as the disc/pad choice and caliper stiffness. Plus, the impact of the Brake-by-Wire (BBW) system that worked on the rear axle. This was set to an aggressive set up early in the year, until several spins under braking forced the team to ease up on the BBW strategy, losing some braking effectiveness, but making the braking phase more consistent.
Brake cooling is a major set up variable, not so much from the heat in the brakes, but how the brake warms up the wheel and in turn the tyre. Ductwork around the brake being tuned for individual wheel heating\cooling.
Also the brake ductwork is used for overtly aerodynamic ends, with both the external and internal ductwork having an effect.
The external side fitted to the inner face of the brake ‘drum’ with the leading vane and its twisting in vane like shaped along its lower edge, to the complex flicks and vanes fitted to the ducts vertical trailing edge. At aero biased tracks, this consisted of a thin vertical vane that joins to both a large and smaller flick as it rises vertically behind the front suspension.
Internally the brake duct did not sport the blown wheel nut set up of its rivals, in an attempt to push the front tyre wake outboard. But instead through-flow ducts fed by the mesh covered inlet, collected and routed airflow from the inner face to out through the wheel, for a similar outwash effect.
An apparently small detail, but one that drew driver attention throughout the year, was the seat. Albeit with different issues for each driver.
Hamilton initially had issues with heat coming through the seat into the cockpit. At first it was though it was heat from electronics mounted within the cockpit, but it transpires it was heat from the sidepods radiators being pulled into the cockpit. The monocoque has a number of openings in the cockpit to allow pipes and wiring to exit into the sidepods. The resulting ‘hole’ is blocked up with a pink putty looking a lot like bubble gum. If this doesn’t create a proper seal, the low pressure inside the cockpit pulls in the hot air from the sidepods, creating the thermal issue for the drivers. More diligent sealing and gold reflective foil on the back of Hamilton’s seat resolved the issue. Hamilton was also noted to have a seat with a higher and lower mounting position, not something I have heard of before.
Rosberg meanwhile applied lots of thought to his seat set up, during the year head three specifications. The Mk1 seat can be seen to have padding for the shoulder and the spine areas. then a Mk2 was tested around Canada and Austria, will Rosberg diligently spending time on the Thursday trying out the different specs. I never noticed the Mk2 seat fitted during a live session, although later in the year a Mk1.2 appeared and was seen in use during live running.
Both drivers are very different racers and personalities, this variation extended into the cockpit. Both drivers had subtly different cockpit set ups. Hamilton started the season with an Arai helmet and after a period of indecision ended up racing a Bell instead, Rosberg meanwhile remained a long term Schuberth user. The Schuberth is distinctly different to both the bel and aria, which are fairly similar in shape. The deeper chin bar and more pointed shape differentiates the Schuberth helmet, this also marks a distinction between Hamilton and Rosberg’s car. Rosberg always raced a wind screen with a series of “V’s” cut out of it, Hamilton had a lower and uncut screen. The airflow tripped up by the screen affects the lift and buffeting the drivers helmet experiences, so the driver preference and helmet design made a difference here.
After some divergence last year, both drivers had the same basic steering wheel this year. The button functions differ between the two drivers, but the positioning of the 9 rotaries and ~20 buttons are the same, although Rosberg has several 3D printed shrouds around some of his buttons to identify the button and guide his fingers.
Behind the steering wheel the paddle set up was similar, an upper rocker style gear shift paddle allows up and down shifts by either pushing\pulling the paddle. Hamilton’s gear right paddle has an extension to allow his fingers to be near the shift paddle when placed on the clutch paddles at the race start. Rosberg had two such extensions below both sides of his gear paddle. Just as with the Brake-By-Wire strategy, Mercedes had an initially aggressive race start strategy, but this was eased off after some erratic starts, which in turn lead to several slow starts, before the strategy and the change in pre-race routines levelled off the start performance.
Rosberg also needs more clearance around his steering wheel, so the removable horseshoe cockpit padding has small cut outs either of the steering wheel. Hamilton’s are straight.
The W06’s upper body lines are similar to the 2014 cars, albeit the two roll hoop inlets were largely discarded in 2015. The roll hoop inlet is split to feed the airbox and also the rear mounted ERS water cooler. The remaining top bodywork was tucked in tightly around the engine and gearbox, the tail end limited by the exhaust pipe and the rear wing mounting wrapped around it.
The exhaust was a long single piece, meeting a short stub pipe emerging from the turbo. With separate pipes feeding in from the two wastegates.
As the year proceeded, the top body was shrunk even further and the ERS cooler enlarged, creating a slimmer profile but one interrupted by blisters to clear engine mounts and the cooler. This thinning created a more accentuated shark fin over the spine of the engine cover. A small cooling outlet was a constant feature of the engine cover, this venting hot air passing around the wastegate’s hydraulic actuator
The thin air and heat of Mexico forced a dedicated cooling set up, with the roll hoop ‘ear’ inlet returning to feed a repositioned cooler behind the usual ERS cooler.
With a water cooler intercooler in the back of the rear bulkhead, the sidepods were small by only needing to cool the Engine oil\water and the intercooler water. As with the top body, the sidepods slimmer as the year went on. The slimming of the coke bottle exit, also exposed the shape of the vane formed into the tail of the car. This unique design beats the Y75 rule on rear bodywork, by blending into the bodywork, creating a useful turning vane. This started out as a “R” shape, the vane curling down to join to the floor. This shape grew larger, before late in the season the vane became more of a “C” shape by merging back into the sidepod and not the floor.
Both the floor design and rear ride height on the W06 were not as aggressive as many other teams. Rake was not as pronounced and rear ride height lower by several centimeters over Red Bull, although this was played with late in the year with trails at higher rear heights via spacers set into the rear end. The diffuser sported the common outswept near side-exit design, with its expansion ratio capped by a more rounded profile at the outer corners of the diffuser. This area being worked hard by the floor’s outer foot plate and large upright gurney\face. Across its width a simple single element flap worked the diffuser’s trailing edge, again now where near as aggressive as others in this area.
The Y100 area is worked hard, with a variety of upright gurney\wing profiles passing up around the rear crash structure and a series of vortex generators spanning behind the plank along the reference plane. Later in the season, the Monkey seat made a more common appearance and the rear crash structure gained a pair of ear like winglets below it.
Rear wing design varied surprisingly through the year, with the same basic endplate design being varied with slightly different slot set ups. The top rear wing started as a straight near 2D profile, but for lower drag races, the outer corners were beveled off, to reduce induced drag. Then for Spa and Monza far smaller delta shaped wings were brought in. the Monkey seat varied from absent to the full six element design, according the circuit and with several intermediate specifications available.
As with last year the gearbox and rear inner suspension remained kept out of sight throughout the year. Little is known about the set up, but it’s known the gearbox continues the cartridge set up, with the gear cluster housed within a Cast Titanium inner case, then the outer case is largely a structural carbon fibre item passing the suspension loads into the chassis. The top of the carbon outer case is flat, being as low as the engine’s upper mounts just 345mm above the reference plane, with the turbo exhaust exiting though an opening in this flat face. Otherwise the outer case is contoured particularly around the upper rear wishbone mounts, creating a low rear impact structure that has to rise up to meet the mandatory height for the tail light.
The rear suspension utilises pull rods, as is standard throughout the grid this year, the lower rear wishbones are aligned with and enclose the driveshafts. While the upper wishbone sits very high to space it from the lower wishbone, the upper outer ball joint being outside the wheel itself. It’s likely the rear inboard suspension features similar hydraulics, springs, dampers and inerters to the that on the front suspension.
Having great success and enviable resources allows a team to raise its game in all areas, for Mercedes this included the garage set up. Not only the darkly lit pit garage with little in the way of wall mounted hardware to clutter the limited garage, space but also the tools and systems the team use.
The central workstation with the PC screens is the hub of the garage, the engineers use the systems not only to track lap times and telemetry data, but an application lists the set up options for the car, so if the engineer want more downforce or different brake cooling, the screen provides a look up of the specification, showing the CAD assembly drawings of the parts needed to fit to make the set up change. Other teams make do with printed books of set up options.
The cordless cooling fans fitted to the car when in the pits and on the grid, are 3D printed, with fluorescent panels to ensure that are not left in place.
The pit crew are obviously well drilled and well prepared, the pit crew wearing a new Schuberth helmet design this year. For quick nose changes, the front end mechanics wear a backpack, inside is a gas cylinder charged to power a hand tool to allows the mechanic to shift even the stubbornest nose mounting after an incident. Not a level or preparation we are used to seeing.
Teams obviously use a lot of computer equipment and this is not unusual to have it linked over Wi-Fi to the garage server rack. Mercedes have gone step further and started to use the latest Wi-Fi protocols for fast data transfer from the car. A project with technical partner Qualcomm now allows the huge amount of tyre temperature data to be taken off the car before it’s even parked in the garage! Already the standard telemetry is uploaded via microwave burst and the pit umbilical cable, this is good for the numeric data, but the tyre temperature cameras collect video-like data, too large to be stored on the standard data logger and again too large to be transmitted via the usual channels.
So Wi-Fi is used, the camera’s record the data to a separate logger and this has a Wi-Fi card installed. A secure Wi-Fi access point outside the team’s garage connects to the car as soon as it stops outside. The data is transferred and is immediately available to the race engineers, for analysis, especially useful in qualifying session where tyre use is critical in finding the final tenths.