Mercedes: Are they blowing the Front or Rear wing?

Update on how it links to the front wing

Original article/

I’ve heard a lot of reporting about the Mercedes F-Duct stalling the rear wing and the likelihood of other teams already having a similar system.

I can see the logic in why people think that the DRS controlled duct blows the rear wing elements in a bid to reduce drag. I haven’t seen any evidence of this being the case; equally I can see several issues with this theory. The problem with the theories on the DRS duct stalling the rear wing are twofold; firstly the DRS is already cutting immensely, secondly the rules greatly restrict the ability to stall the rear wing. Back in to 2010 teams were using blown slots across the full width of the rear wing, these being used with perpendicular blowing to stall the wing or tangential blowing to act as an additional slot gap for more downforce. The rules introduced in 2011 aimed to prevent both of these types of slot.
To stall either the top rear wing or the beam (lower) rear wing, you need to blow a slot. In the post 2010 rules, slots are banned in any section of the rear wing (via a 100mm minimum radius rule); this ban applies to all three wing elements aside from the middle 15cm. So to use the DRS duct to blow a rear wing slot, all you’ll stall is the very centre section of wing. This area creates very little induced drag (most of that’s created at the wing tips), so stalling it will not improve top speed by much. Thus it will provide very little benefit.

It’s possible the DRS Duct could stall the flow around the sidepod, exhaust or diffuser. I’ve got no information on this, or a valid reason how this would benefit the aero. In my opinion the blowing to stall the front wing is still the most valid theory.  Pictures have merged today of Schumachers car lifted on a crane that shows the slot sunder the front wing. other pictures also show close ups of the rear of the car, do not show any slots in the top or beam wings.

Search on sutton images for pictures d12aus3468.jpg, d12aus3467.jpg, d12aus3465.jpg

I suspect the two ducts leading from the beam wing into the engine cover are part of the system.  Either taking the DRS-duct flow to the front wing directly, or by using the DRS-duct to switch the F-Duct.  I can;t find where the F-duct switch is sited, perhaps inside the rear wing, in which case the two beam wing ducts might be of different uses, one feeding high pressure airflow to the F-Duct and the other feeding the flow to the front wing.  As this is an evolving theory, I’ll post more on this system as we start to understand it better.

I’ve looked at the McLaren, Red Bull and Ferrari rear wings, as yet I can see no shaping to suggest a DRS-Duct is packaged inside the endplates.  There’s little doubt these teams must be working on similar solutions.  Although Red Bull and Lotus may probably not be developing this solution, as they are now querying the FIA on its legality LINK

We have now acceptance by the FIA that the DRS duct is legal, that Mercedes  are running this system and pictures show the duct emerging from the beam wing reaching forwards inside the engine cover. Presumably, to reach towards the front-end of the car. No doubt more information will soon emerge on these systems.

other links:

DRS open showing the duct open beneath the flap (via AMus)


Rear wing no sign of any slots in the middle 15cm


Mercedes: F-Duct Front Wing operated by the Rear Wing DRS

Update on how it links to the Front wing


Something often said of banned developments in F1, is that once understood no solution can be unlearnt. So while the FIA fights to ban technologies that they feel aren’t suited to F1, the teams will always try to apply that solution in a different way.
McLaren understood how to stall a wing by blowing a slot perpendicular the wings surface. This knowledge lead to the F-duct in 2010, as you will recall the FIA moved to ban slots in the rear wing and direct driver interaction with the cars aero. But the knowledge of blown slots to stall wings has remained and it’s been Mercedes who have been busy trying to apply it in other ways. This culminated with the tests of an F-Duct front wing late last year. Rumours continue to fly about the teams use of the F-Duct front wing (FDFW) in 2012. I understand the 2012 Mercedes AMG W03 does have an F-Duct front wing and this is operated by the rear wings DRS. Based on information I have from the sources around the team, and from looking at the cars performance and construction mean I can speculate how and why Mercedes might be using the FDFW.

As detailed in two articles last year, Mercedes are believed to have run blown slots under the front wing to stall the wing at higher speeds. Three reasons came up as to why this would be used; reducing drag, managing wing ride height and managing the cars aero balance. With nothing official being said by Mercedes, we were left unsure as to exactly why a passive FDFW would benefit the car.

Some observations from the Mercedes team last year might aid us in putting a picture together of how the 2012 solution might benefit. Mercedes were the first team to really exploit more of the open DRS effect and use a short chord flap. The open DRS boosted Mercedes top speed and could be used through the lap in qualifying. Despite this benefit the teams did struggle in qualifying, their race performances latterly became better than qualifying suggested. It was clear for Michael Schumacher at Least, that the cars handling wasn’t ideal and the team sought to resolve the cars nervousness.
Bearing these points in mind, the potential benefits of a FDFW become more apparent. Mercedes need more qualifying pace; they can exploit their DRS more frequently during qualifying, but in higher speed turns the cars lacks the balance for the drivers to fully commit through the turn.
If they can cure these issues, then they will further up in qualifying and able to take the fight to the leading teams. I now believe the FDFW works to manage the cars balance in high speed turns when the DRS is activated. As DRS reduces both rear drag and downforce, the car becomes unbalanced in downforce front-to-rear. In other words pointy or oversteering. Which in high speed turns in qualifying is hard to handle. At higher speeds even with DRS reducing rear wing downforce, the car has enough downforce to make it around corner, the problem is how to make the car more balanced front-to-rear when DRS is activated.
The FDFW we saw last year appeared to be passive, this uses nothing other than airspeed to trigger the slot to blow enough to stall the front wing. If matched to the speed DRS would be used at (in qualifying), the passive FDFW would help balance the car, by reducing front downforce to match that of the rear. However the front wing would always stall at these speeds, whether DRS was in use or not, so outside of qualifying the wing would stall and the car would understeer. With Parc Fermé rules in force, the team cannot change the FDFW between qualifying and the race.
Another issue with the passive FDFW, is that under braking as air speed reduced, the wing would need time to start working again. But this early phase of braking is just when the driver needs the most downforce. What the FDFW ideally needs is a method to link its activation to that of DRS, in other words an active F-duct.
As we’ve already mentioned, driver activation is not allowed, as are any other moving parts to directly alter the airflow. This brings up the Designers favourite interpretation in the rule book, primary and secondary purpose. Any part on the car can be for a primary purpose; sometimes any secondary purpose is banned or restricted. However in most cases the rules are vague and Designers are free to find secondary uses for a solution on the car. Examples of this are the cooling fans on the Brabham Fan car, the engine blowing off throttle for blown diffusers or brake torque altering ride height on the Lotus Reactive Ride Height system. In each case the first element was legal as its primary purpose was as stated, but a secondary purpose was able to be exploited.

The DRS rules are quite clear that the flap must not be shaped to allow other aerodynamic benefits. In fact this wording affects only a portion of the flap and additionally the endplate is excluded from this wording. If the team could find a way to blow into the front wing a duct when DRS is activated, then the FDFW could work synchronously with the DRS.

The hingeplate the flap mounts to, closes a hole when DRS is closed. When DRS is open the duct is revealed and the F-duct stalls the front wing

I believe Mercedes have found a way, by creating a duct through the endplate. When DRS is closed, the flap and the plate it attaches to is in a nearly vertical position. When DRS opens, the area the flap initially covered is exposed. If this area featured an opening that lead into a duct inside the endplate, when DRS opened the high pressure above the wing would force flow through the duct. With this duct then routed through the car to the front wing, when DRS is open the FDFW would be blown and stall in unison with the rear wing. Clearly when DRS closes the duct would be closed off and the duct would stop blowing the FDFW, restoring front and rear downforce.

When DRS is open, the duct passes into the beam wing and through the car. Eventually reaching the front wing slot to stall the wing.

Some evidence around the rear wing of the W03 shows this could be possible. We have to be careful to pinpoint every feature on the rear wing as being FDFW related as the DRS mechanism is hidden inside the endplate as well. Some access panels on the wing could be for DRS, FDFW or other purposes, some might be for both. In my research I’ve yet to see a clear high resolution shot of the Mercedes with DRS open, this is unusual as most other teams have been seen with the DRS in effect. Equally clear pictures of the inside of the endplate, where the flap meets the endplate, are in short supply. With this lack of material I can propose a solution, although the actual parts may diffuser is location and appearance. Its expected at this weekend Australian GP the rear wing duct will be exposed as the car uses DRS on the straights. We will need photographers with a big lens and steady hand to catch sharp pictures of the inside face of the endplate, when DRS is activated.

Evidence of the duct can be seen on the car, when the car is not moving. Clearly the W03 rear wing endplate is quite thick, an access panel that houses the DRS actuator is outboard of the flap\endplate intersection, plus there is another panel in line with the beams wings intersection with the endplate. I’d suggest the duct is opened by the flap and hinge plate, the duct then routes through the double skinned endplate down into the beam wing. This then exits through the duct that mounts the beam wing to the gearbox. There’s a tortuous route for the duct through the car to reach the front wing, but this isn’t that dissimilar to the 2010 F-Duct routing. As with McLaren in 2010, the trick is to design the duct into the car at an early stage to minimise losses through the ductwork. This usefully makes it harder, but not impossible to copy. To copy this set up the monocoque needs to be altered and the nose cone needs the apertures into the front wing mounting pylons to feed the airflow into the front wing itself. This requires time to redesign and potentially re-crash test any changes.
But, can this set up be legal? The act of stalling a front wing through a blown slot is legal, although F-ducts are banned, it’s only via the slot in the rear wing that this was achieved. Direct driver intervention is banned, but the driver is allowed to operate the DRS, so any secondary aerodynamic effect of that is not prohibited in the rules.
Although the rules allow this, it’s possible the FIA could issue a Technical Directive on the matter, that any overt secondary effect of using DRS is not allowed and the whole solution could be banned in a stroke.

With a tight and competitive season in prospect qualifying performance will be critical. Notwithstanding the potential structural work to allow the duct to pass through the car, the DRS activated F-duct Front wing is an attractive option for the other leading teams.

F1 2012: Rules, Designs and Trends

For 2012 we will have a raft of rules changes that will alter the look and performance of the car. For most of the new cars, we will immediately see the impact of the lower nose regulations. Then the big story of 2010-2011 of exhaust blown diffusers (EBDs) comes to an end with stringent exhaust placement rules and a further restriction on blown engine mappings.
Even without rule changes the pace of development marches on, as teams converge of a similar set of ideas to get the most from the car. This year, Rake, Front wings and clever suspensions will be the emerging trends. Sidepods will also be a big differentiator, as teams move the sidepod around to gain the best airflow to the rear of the car. There will also be the adoption of new structural solutions aimed to save weight and improve aero.
Last of all there might be the unexpected technical development, the ‘silver bullet’, the one idea we didn’t see coming. We’ve had the double diffuser and F-Duct in recent years, while exhaust blown diffusers have thrown up some new development directions. What idea it will be this year, is hard, if not impossible to predict. If not something completely new, then most likely an aggressive variation of the exhaust, sidepod or suspension ideas discussed below.

2012 noses

The most obvious rule change for 2012 is the lowering of the front of the nose cone. In recent years teams have tried to raise the entire front of the car in order to drive more airflow over the vanes and bargeboards below the nose. The cross section of the front bulkhead is defined by the FIA (275mm high & 300mm wide), but teams have exploited the radiuses that are allowed to be applied to the chassis edges, in order to make the entire cross section smaller. Both of these aims are obviously to drive better aero performance, despite the higher centre of Gravity (CofG) being a small a handicap, the better aero overcomes this to improve lap times.

A safety issue around these higher noses is that they were becoming higher than the mandatory head protection around the cockpit, in some areas this is as low as 55cm. It was possible that a high nose tip could easily pass over this area and strike the driver.

The front section of chassis will be as high as possible (at 62.5cm) and radiussed into a "V" shape

So now the area ahead of the front bulkhead must be lower than 55cm. However the monocoque behind this area can remain as high as 62.5cm. Thus in order to strive to retain the aero gains teams will keep a high chassis and then have the nose cone flattened up against this 55cm maximum height. Thus we will see these platypus noses, wide and flat in order to keep the area beneath deformable structure clear for better airflow. The radiussed chassis sides are still allowed so we will also see this 7.5cm step merged into the humps a top of the chassis.
Areas below and behind the nose are not allowed to have bodywork (shown yellow in the diagram), so small but aggressive vanes will have to be used, or a McLaren style snowplough. Both these devices drive airflow towards the leading edge of the underfloor for better diffuser performance.

New exhausts

Exhausts must be high up on the sidepod, so cannot blow the diffuser

Having used the engine via the exhausts to drive aerodynamic performance for the past two years, exhaust blown diffusers will be effectively banned in 2012. The exhausts must now sit in small allowable area, too high and far forward to direct the exhausts towards the diffuser. The exhausts must feature just two exits and no other openings in or out are allowed. The final 10cm of the exhaust must point rearwards and slightly up (between 10-30 degrees). Allied to the exhaust position, the system of using the engine to continue driving exhaust when the driver is off the throttle pedal has also been outlawed. Last year teams kept the engine throttles opened even when the driver lifted off the throttle for a corner. Then either allowing air to pass through the engine (cold blowing) or igniting some fuel along the way (hot blowing). The exhaust flow would remain a large proportion of the flow used when on the throttle, thus the engine was driving the aero, even when the driver wasn’t needing engine power. Now the throttle pedal position must map more closely the actual engine throttle position, thus if the driver is off the throttle pedal, then the engine throttles must be correspondingly closed.

Blown rear wing (BRW): The exhausts will blow upward to drive flow under the rear wing for more downforce

Teams will be faced with the obvious choice of blowing the exhausts upwards towards the rear wing, to gain a small aerodynamic advantage, when the driver is on the throttle. These Blown Rear Wings (BRWs) will be the conservative solution and certainly will be the first solution used in testing.
However, it’s possible to be aggressive with these exhaust designs too. One idea is blowing the rear wing with a much higher exhaust outlet; this would blow tangentially athte wing profile, which is more effective at increasing the flow under the wing for more downforce. Packaging these high exhausts may cause more problems than gains. But last year’s exhausts passing low and wide across the floor suffered a similar issue, but proved to be the optimum solution.

A more aggressive BRW raises the exhaust and blows tangentially under the wing profile, which is more efficient

Even more aggressive solution would be directing the exhausts onto the vanes allowed around the rear brake ducts. If avoiding the brake cooling inlet snorkel, the fast moving exhaust gas would produce downforce directly at the wheel, which is more efficient than wings mounted to the sprung part of the chassis. However the issue here would be the solution is likely to be so effective, that it will be sensitive to throttle position and rear ride height. If these issues can be engineered out, then this is an attractive solution.

An extreme but legal solution is to blow the exhaust on the rear brake duct fins creating downforce directly at the wheel.

Wing ride height and Rake
With rules setting a high front wing ride height and small diffusers, aero performance is limited. So teams have worked out how to work around these rules by angling the entire car into a nose down attitude. This is known as ‘Rake’, teams will run several degrees of rake to get the front wing lower and increase the effective height of the diffuser exit. Thus the front wing will sit closer to the track, than the 75mm when the car is parallel to the ground. While at the rear, the 12.5cm tall diffuser sits an additional 10cm clear of the track, making its expansion ratio greater. Teams were using the EBD, to seal this larger gap between the diffuser and the floor. Without the EBD teams will have to find alternative way to drive airflow into the gap to create a virtual skirt between the diffuser and track.
Furthermore teams have also allowed the front wing to flex downwards at speed to allow it to get closer to the ground, further improving its performance. Although meeting the FIA deflection tests, teams are allowing the wing bend and twist to position the endplate into a better orientation, either for sealing the wing to the ground or directing airflow towards the front tyres wake. Both creating downforce benefits at the front or rear of the car, respectively.
One issue with allowing the wing to ride closer to the ground through rake or flexing, is that at high speed or under braking (when the nose of the car dives), the front wing can be touching the ground. This is bad for both aero and for creating sparks, which will alert the authorities that the wing is not its normal position relative to the chassis. So teams are creating ways to manage front ride height. Traditionally front bump rubbers or heave springs will prevent excessively low ride heights. Also the front suspension geometry runs a degree of geometric anti-dive, to prevent the nose diving under braking.

Antidive geometry in the front suspension is one way to reduce pitch under braking

Last year we saw two additional solutions, interlinked suspension, where hydraulic suspension elements prevent nose dive under braking by displacing fluid in a hydraulic circuit one end of the car to the other end, creating a stiffer front suspension set up. This prevents dive under braking, while keeping a normally soft suspension for better grip.
We have also seen Lotus (nee LRGP) use torque reaction from the front brake callipers to extend the pushrod under braking, creating an anti-dive effect and prevent the nose dipping under braking.

An interpretation of the Lotus Antidive solution, using the brake caliper mounting to operate a hydraulic circuit and extend the pushrod (legally) under braking

These and probably other solutions will be seen in 2012 to maintain the ideal ride height under all conditions.

Front end

A three element endplate-less front wing

Towards the end of last year, front end aero design was converging into a set of similar ideas. Aside from the flexible wing option, already discussed above. The main direction was the use of a delta shaped three\four element wing, sporting no obvious endplate. The delta shape means that most of the wings downforce is created at the wing tip; this means less energy is taken from the airflow towards the inner span of the wing, which improves airflow at the rear of the car. Also the higher loading near the wing tip creates a stronger vortex, which drives airflow around the front tyre to reduce drag. Three wing elements are used, each being similar in chord length, rather than one large main plane and much smaller flaps. This spaces the slots between the elements out more equally, helping reduce airflow separation under the wing. More slots mean a more aggressive wing angle can be used without stalling. At the steepest outer section of wing, teams will mould a fourth slot in the flap to further manage airflow separation.
First introduced by Brawn in 2009, the endplate-less design is used as it’s more important to drive airflow out wide around the front tyre, than to purely maintain pressure difference above and below the wing. Rules demand a minimum amount of bodywork in this area, so vanes are used to both divert the airflow and meet the surface area regulations. This philosophy has now morphed into the concept, where the wing elements curl down to form the lower part of the endplate. Making the wing a homogenous 3D design, rather than flat wing elements and a separate vertical endplate.

Arched sections (yellow) of wing, help drive vortices to divert airflow along the car

A feature starting to emerge last year was arched sections of wing. Particularly near the mandatory neutral centre 50cm section of wing. These arched sections created elongated vortices, which are stronger and more focussed than tip vortices often used to control airflow. In 2012 many teams will create these unusual curved sections at the wings interface with the centre section.

Extending the front wing mounting pylons helps to make use of the middle 50cm of wing

Above this area, the pylon that mounts to the wing to the nosecone has been exploited to stretch he FIA maximum cross section to form the longest possible pylon. This forms the mounting pylon into endplates either side of the centre section of wing and along with the arched inner wing sections, help create the ideal airflow 25cm from the cars centreline (known as the Y250 axis).

Pointing a section of front wing profile at a suitable vane on the front brake ducts is one way gain aero performance.

In 2011 Mercedes GP used a section of the frotn wing to link up with the fins on the brake ducts, this created an extra long section of wing.  Vanes on the front brake ducts are increasingly influential on front wing performance and front tyre wake.
Mercedes GP also tried an innovative F-Duct front wing last year. This was not driver controlled, but rather speed (pressure) sensitive. Stalling the wing above 250kph, this allowed the flexing wing to unload and flex back upwards at speed, to prevent the wing grounding at speed. But the effect altered the cars balance at high speed, and the drivers reportedly didn’t like the effect on the handling. I’ve heard suggestions that the solution isn’t planned for 2012.

With so much of the car fixed within the regulation, it’s becoming the sidepods that are the main area of freedom for the designers. Last year we saw four main sidepod concepts; Conventional, Red Bull low\tapered, McLaren “U” shape and Toro Rosso’s undercut.
Each design has its own merits, depending on what the designer wants to do with the sidepods volume to get the air where they want it to flow.

An undercut in the sidepod is one way to drive good flow around the sidepod to the diffuser

This year I believe teams will want to direct as much airflow to the diffuser as possible, Red Bulls tiny sidepod works well in this regard, as does the more compromised Toro Rosso set up. Mclarens “U” pod concept might be compromised with the new exhaust rules and the desire to use a tail funnel cooling exit. However the concept could be retained with either; less of top channel or perhaps a far more aggressive interpretation creating more of an undercut.

Using a slight McLaren "U" shape to the sidepod may still work in 2012

Part and parcel of sidepod design is where the designer wants the cooling air to enter and exit the sidepod. To create a narrower tail to the sidepod and to have a continuous line of bodywork from sidepod to the gearbox, the cooling exit is placed above the sidepod, in a funnel formed in the upper part of the engine cover. Most teams have augmented this cooling outlet with small outlets aside the cockpit opening or at the very front of the sidepod.

The tail funnel (light yellow) is a good cooling outlet method, as it reduces the size of the coke bottle section of sidepod

To let more air into the sidepod, without having to create overly large inlets, teams will commonly use inlets in the roll hoop to feed gearbox or KERS coolers.

Other aero
Even without the exhaust blowing over the diffuser, its design will be critical in 2012.
As already mentioned the loss of the exhaust blowing will hurt the team’s ability to run high rear ride heights and thus a lot of rake. Unobstructed the EBDs exhaust plume, airflow will want to pass from the high pressure above the floor to the lower pressure beneath it. Equally the airflow blown sideways by the rear tyres (known as tyre squirt) will also interfere with the diffuser flow.

The Coved section of floor between the tyre and diffuser will be a key design in 2012, as will cold blown starter holes and trailing edge flaps

Before EBDs teams used a coved section of floor to pickup and accelerate some airflow from above the floor into the critical area between the diffuser and rear tyre. I predict we will see these shapes and similar devices to be used to keep the diffuser sealed at the sides.
Last year we saw teams aid the diffusers use of pulling air from beneath the car, by adding large flap around its trailing edge. So a high rear impact structure raised clear of the diffusers trailing edge will help teams fit these flaps around its entire periphery. Red Bull came up with a novel ideal by creating a duct feeding airflow to the starter motor hole; this improves airflow in the difficult centre section of the diffuser. Many teams will have this starter motor hole exposed by the raised crash structure, allowing airflow to naturally pass into the hole. However I expect some vanes or ducts to aid the flow in reaching this hole tucked down at the back of the car.

Tapered flaps and top mounted DRS pods will be a direction for 2012

DRS was a new technology last year. We soon saw teams start to converge on a short chord flap and a high mounted hydraulic actuator pod. DRS allows the rear wing flap to open a gap of upto 50mm from the main plane below it. A smaller flap flattens out more completely with this 50mm gap, reducing drag more effectively than a larger flap.
As drag is created largely at the wing tips, I would not be surprised to see tapered flaps that flatten out at the wing tip and retain some downforce in the centre section. Teams may use the Pod for housing the actuators, although Mercedes succeeded with actuators hidden in the endplates. Having the pod above the wing clears the harder working lower surface, thus we will probably not see many support struts obstructing the wing.


Variations on William low line gearbox and differential will be followed for this year

Super slim gearboxes have been in vogue for many years, Last year Williams upped the stakes with a super low gearbox. The normally empty structure above the gear cluster was removed and the rear suspension mounted to the rear wing pillar. Williams have this design again for 2012, albeit made somewhat lighter. With the mandatory rear biased weight distribution the weight penalty for this design is not a compromise, while the improved air flow the wing is especially useful in 2012. So it’s likely the new cars will follow the low gearbox and low differential mounting in some form.

Rear pull rod suspension will be all but universal this year

A lot is said about Pull rod rear suspension being critical for success. In 2011 only a few teams retained push rod rear suspension (Ferrari and Marussia). I would say the benefits between the two systems are small; pushrod trades a higher CofG for more space and access to the increasingly complex spring and damper hardware. Whereas pull rod benefits from a more aerodynamically compact set up and a lower CofG. I still believe either system works well, if packaged correctly.
At the front it’s unlikely pull rod will be adopted. Largely because the high chassis would place a pull rod at too shallow an angle to work efficiently. Regardless the minimum cross section of the footwell area, discounts any potential aero benefits. Leaving just a small CofG benefit as a driver to adopt this format.

Undercut roll hoops with internal metal reinforcement will be a common feature to drive airflow to the rear wing

Most teams now use a metal structure to provide strength inside the roll hoop; this allows teams to undercut the roll hoop for better airflow to the rear wing. Even though last year two teams followed Mercedes 2009 blade type roll hoop, for Caterham at least, this isn’t expected to return this year. Leaving the question if Force India will retain this design?

Electronics and control systems
The 2012 technical regulations included a large number of quite complex and specific rules regarding systems controlling the engine, clutch and gearbox. It transpires that these are simply previous technical directives being rolled up into the main package of regulations. Only the aforementioned throttle pedal maps being a new regulation to combat hot and cold blowing.

While I still try to crack that deal to make this my full time job, I do this blog and my twitter feed as an aside to my day job. In the next few weeks I plan to attend the launches and pre-season tests. If you appreciate my work, can I kindly ask you to consider a ‘donation’ to support my travel costs.

UPDATE: Mercedes F-Duct Front Wing

Another possibility with the Mercedes stalling front wing is that it allows an opportunity to play with the linearity of the cars ride height. In particular the proximity of the splitter to the ground at different speeds. Looking at this in comparison to other possible uses, I would suggest this is a more realistic and beneficial solution than those initial proposed (

As has been much discussed, the front wing needs to run as low as possible to create downforce. To achieve this teams run as lower front ride height as possible. The limitation of a low front wing ride height is the front splitter grounding, this becomes an increasing problem as speed increases and the aero load builds up and compresses the front suspension. So at the ‘End of the Straight’ (EOS) at very high speed the car is at its lowest and splitter is grounding. This forces the car to have a higher ride height, to keep the plank from wearing away in the EOS condition. Thus at lower speeds the front ride height is correspondingly higher, compromising the potential of the wing.

If Mercedes stall the front wing as the car reaches top speed, hence above the speed of any corner on the track. Then when the wing stalls, the load on the front axle will suddenly decrease and the front ride height will increase. Effectively the ride height\speed map is no longer linear. Ride height will decrease linearly at lower speeds, then above the speed of the circuit’s fastest corner, the wing stalls and ride height increases.
What this allows the race engineers to do is shift the ‘ride height curve’ down the map for a lower initial (static) ride height. Knowing that the splitter will not ground in the end of straight condition. Therefore with the unstalled wing having a lower ride height, more downforce can be generated. When the wing is stalled the lack of downforce is less consequential as the car is on the straight. Plus there may still be the small boost in top speed from the lack of induced drag from the stalled wing.

One other potential of such a solution is the front wing grounding. We have seen the midseason version of the Mercedes front wing ground quite easily in some turns this year. So as with splitter ride height, endplate ride height at top speed may become the limiting factor in benefiting from the wing flexing at lower speeds. Stalling the wing on the straight will see the load on the wing decrease and the wing will naturally flex upwards. Giving the opportunity to flex more at slow speeds and have the stall prevent grounding on the straight.

In comparison to the manipulation of the CofP to resolve handling problems I initially proposed, this would be a more likely purpose of the stalling wing. Perhaps more importantly this would be a universal solution, one that other teams could legally adopt in preference to flexible splitters or excessive rear ride height to achieve lower front ride heights.

Mercedes F-Duct Front wing

Note: Updated 24th Oct

Mercedes GP are rumoured to be running a novel front wing. This has been reported in the three major F1 magazines (AMuS, Auto sprint and Autosport). It seems the front wing uses the nose hole to blow a slot under the wing. Although this is a completely passive system (i.e. no moving parts or driver intervention), the fact that it alters aero performance at speed, has seen it dubbed as an F-duct Front Wing.

This solution was first heard of by Michael Schmidt of German magazine ‘Auto Motor und Sport’ (AMuS). Schmidt passed the tip off to Giorgio Piola who spent hours in the pitlane observing the Mercedes car and how mechanics handled the different wings. A task made additionally difficult, as he could not arouse suspicion by Mercedes and give away the fact he was researching the tip off.
He found only two noses had the nose-hole with the splitter and that these wings were only carried parallel to the ground when moved around the pitlane. The final piece of the jigsaw was when he saw a mechanic inspect the wing with his hand leading to understand the slot placement and this information allowed him to work out the system and draw it for the aforementioned magazines. Its remarkable such a tiny detail can be observed and goes to show the hard work that went into Piola exposing this innovation.

AMuS article

Autosprint article

As described in the illustrations and texts, the wing assembly (including the nose) is as follows. The nose hole is used to pass air down through the front wing pylons into a slot on the underside of the wing. It appears that the slot has a wide span and is very narrow.

The nose hole feeds air through a duct into a slot under the front wing

This design is somewhat similar to Mercedes early 2010 F-duct rear wing, which was passive. The driver didn’t have a control duct, as with the McLaren system. Instead the ductwork would only blow with enough force to stall the rear wing at a certain airspeed. Tricky to design and tune, this system worked well for Mercedes last year. Its not improbably that just such a system could be made to work on the front wing.

Aiding downforce or stalling the wing?
Typically slots in the wing are for two purposes; aiding or stalling the flow over the wings surface. How the slot creates these two very different effects depends on the slots angle to the wings surface.

To aid the airflow, you need a slot blowing nearly inline with the surface and airflow. Known as Tangential flow, this flat entry angle creates a relatively wide slot when viewed externally.

To stall the airflow, you need a slot blowing at near right angles to the surface. This creates a narrow slot when viewed externally.

Looking at what you need to aid or stall the airflow also requires different placement of the slot.

To aid the airflow, you would inject the flow from the slot in an area downstream on the wings surface where the boundary has slowed and thickened. On a front wing this would arguably be somewhere on the flap towards its trailing edge.

To stall a wing, you want to upset the airflow where it’s moving quite fast, for a front wing it would be placed towards the leading edge of the wing. Last year with F-ducts we saw the stalling slots initially placed on the flap, until Renault placed theirs on the main plane for a better stalling effect.

This analysis suggests the narrow slot towards the leading of the front wing is for stalling not aiding the airflow.

Why stall the wing?
However, while we have got this far in reverse engineering the Mercedes front wing. We now need to work out what the benefit of stalling the front wing is. When stalling aerodynamics there are two possible benefits. Reducing drag for more top speed or reducing downforce.

Drag Reduction
For a front wing the drag loss wouldn’t be that beneficial on top speed. Sitting within the frontal area of the cars silhouette the front wing has very little form drag. However, induced drag from vortices produce particularly at the outboard ends is a factor, but far less than with rear wings. With teams increasingly bending their wings down at speed to gain greater downforce, they are creating most of the load towards the wing tips. By making the wing more aggressive at its outer ends, means that more vortices will be produced and sent around the front tyre. This flow structure creates drag and stalling the wing, especially near the tips would reduce this drag and boost top speed. Martin Whitmarsh was quoted in the AMuS article as suggesting a 5/8kph gain from stalling the front wing.

Drag is induced by the vortices created at the wing tips

With the front wing stalled, some of the energy it robs the airflow can pass towards the underfloor, increasing the pressure at its leading edge, forcing more flow under the floor for more downforce. With more downforce from the underbody, a smaller rear wing can be raced, which also creates less drag for more top speed.

Aero Balance
But that may not be the greater goal of stalling the front wing. Instead the aim may be managing the balance of the car through out its speed range. This would be done by the loss of downforce altering the cars Centre of Pressure.

Firstly, let’s review what the front wing does for the cars dynamics at different speeds. An f1 cars downforce is produced largely by the front wing, rear wing and the floor. With the front and rear wings being the main tuning elements. By tuning the front and rear downforce you alter the cars Centre of Pressure.
Centre of Pressure (CofP) is the balance of downforce at the front and rear axles. As such it’s analogous to being the aerodynamic equivalent of Longitudinal CofG (balance of mass between the axles). CofP is also known as termed as aero balance.
Typically the CofP position closely matches that the CofG. Starting from around 1-2% behind the CofG, then as the car gains speed the car gets lower making the front wing and diffuser work better. Fairly soon the stepped bottom\plank choke flow into part of the diffuser, this robs the diffuser of some downforce. While as the front wing gets closer to the track, it works in ground effect to create even more downforce. The combined effect of the loss of some rear downforce and gain in front downforce is that the CofP moves further forwards.

Such is the potential of the front wing and the near equal tyre sizes front to rear; an F1 car is largely limited on corner entry by the rear grip available. In low to mid speed turns the car needs a slight rear bias to the CofP, this prevents the car suffering corner entry oversteer. Where the car wants to spin as it approaches the apex. Too much front wing in these corners will make the car too pointy and hinder laptimes.
In faster turns the front wing can lead the car. The drivers turn in gentler to fast turns, which creates less lateral acceleration at the rear axle. So it’s rare for the rear to step out on turn-in to fast corners. Thus, at higher speeds you can have a CofP biased towards neutral or the front. Last year with the adjustable front flap, (rather than used for the overtaking balance adjustment for which it was designed) teams would use alter the front flap angle into a fast turn.

So typically you wouldn’t want to shed front downforce for fast turns, by stalling the front wing. Stalling the front wing will reduce front downforce and drive the CofP rearwards, robbing the driver of front axle load just when he needs it.

But, the move towards a rear biased high speed set up could be a response to other problems with the chassis. We knew the 2010 Mercedes W01 suffered understeer and Michael Schumacher didn’t like that facet of its handling, even though Nico Rosberg could cope with it. Perhaps Schumacher’s style of being aggressive on initial turn in, helps the car to rotate into turns more to gain speed through slow\medium speed corners. This tendency corner entry oversteer wasn’t present in the 2010 chassis.
The 2011 W02 is shorter and designed to rotate better, it certainly isn’t a natural understeer. We can suggest this forwards bias, as a possible reason for the car being hard on its rear tyres.
So if the W02 has a forward biased aero balance, this would move the car closer towards corner entry oversteer. We’ve also seen the mid season wing upgrade displays some flexibility, as with many teams front wings. This would have the effect of moving the front wing in yet closer proximity to the track and create even more front downforce at higher speeds.
So with the W02, as speed increases and the CofP moves forwards. Now the corner entry oversteer create a danger of high speed spins, the team need to calm the chassis down a little. So when the wing stalls, the CofP moves rearwards and gives the drivers more confidence with a little understeer. In Michaels case his naturally aggressive turn in is tolerated and as we’ve seen Rosberg can cope with understeer. So both drivers benefit. This might also save the tyres from slip in high speed turns, which could be detrimental to the tyres grip.

Front Ride Height

Another possibility with the stalling front wing is that it’s allowing an opportunity to play with the linearity of the cars ride height. In particular the proximity of the splitter to the ground at different speeds.

As has been much discussed, the front wing needs to run as low as possible to create downforce. To achieve this teams run as lower front ride height as possible. The limitation of a low front wing ride height is the front splitter grounding, this becomes an increasing problem as speed increases and the aero load builds up and compresses the front suspension. So at the ‘End of the Straight’ (EOS) at very high speed the car is at its lowest and splitter is grounding. This forces the car to have a higher ride height, to keep the plank from wearing away in the EOS condition. Thus at lower speeds the front ride height is correspondingly higher, compromising the potential of the wing.

If Mercedes stall the front wing as the car reaches top speed, hence above the speed of any corner on the track. Then when the wing stalls, the load on the front axle will suddenly decrease and the front ride height will increase. Effectively the ride height\speed map is no longer linear. Ride height will decrease linearly at lower speeds, then above the speed of the circuit’s fastest corner, the wing stalls and ride height increases.
What this allows the race engineers to do is shift the ‘ride height curve’ down the map for a lower initial (static) ride height. Knowing that the splitter will not ground in the end of straight condition. Therefore with the unstalled wing having a lower ride height, more downforce can be generated. When the wing is stalled the lack of downforce is less consequential as the car is on the straight. Plus there may still be the small boost in top speed from the lack of induced drag from the stalled wing.

One other potential of such a solution is the front wing grounding. We have seen the midseason version of the Mercedes front wing ground quite easily in some turns this year. So as with splitter ride height, endplate ride height at top speed may become the limiting factor in benefiting from the wing flexing at lower speeds. Stalling the wing on the straight will see the load on the wing decrease and the wing will naturally flex upwards. Giving the opportunity to flex more at slow speeds and have the stall prevent grounding on the straight.

Looking at the options listed above, I would definitely say the cars wing is stalling.  with little to be gained from drag reduction the stalline is most likley to create another effect on the chassis.
In comparison to the manipulation of the CofP to resolve handling problems, the speed sensitive ride height control would be a more likely purpose of the stalling wing. Perhaps more importantly this would be a universal solution, one that other teams could legally adopt in preference to flexible splitters or excessive rear ride height to achieve lower front ride heights.

So if we now accept that this theory is how the might wing work, we need to look at the legality and construction of the set up. Firstly a passive system that involves no moving parts or driver intervention is legal. Secondly the rules on the closed sections forming the front wing are much freer than those applied to the rear wing. So slots can be legally made across the side spans of the front wing. Clearly it would be legal in both of these respects, that the stalling slot can be made to blow at certain speeds.
The biggest issue is with the nose hole itself. This is covered in the rules and is allowed for the purposes of driver cooling. This being worded into the nose cone regulations for 2009 to prevent Ferrari style slotted noses. We know the nose hole is used to blow the front wing for several reasons. Firstly Mercedes do have the nose hole, but rarely use it, instead the duct moulded into the access panels atop the chassis are normally used for driver cooling. Most of the time the nose hole is sealed up with clear tape.
But one crucial picture in the AMuS gallery accompanying their article, was of the car with the nose removed, showing a black carbon fibre cover going over the front bulkhead. This would seal the nosecone, such that air entering the nose hole would not pass into the cockpit and instead pass down the wings support pylons. With this panel in place the nose hole cannot function as driver cooling and goes against the rules. Perhaps this set up using the nose hole was just at Suzuka for testing, as Teams are unable to do much full scale testing away from the circuit. It could be legally run in a Friday practice session, as teams are given some leeway to test parts which might otherwise be unacceptable to the scrutineers. As long as the parts aren’t run for qualifying, then apparently illegal parts can get limited Friday running.
So for 2012 the wing might gain its inlet from another position. At Suzuka, the use of the nose hole might have been a good way to disguise the system when it was tested.

I have to thank the many people who aided me in my countless questions on this design. Thanks for your patience.

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.

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.


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

Happy New Year – RedBull RB6 Illustration (Wallpaper)

I’ve been drawing this big detail – big scale illustration of the RB6 as a prelude to a prediction of the 2011 car designs.  So I’d thought I’d post the 2010 RB6 version up as a wallpaper in mono at 1280 resolution.  I’ll do larger sizes on request with or without logos (mail me).

Have a great New Year and thanks for supporting me in my first year Blogging and Tweeting.  Next year will be my tenth covering the technicalities of the sport, so I’ve got some new ideas up my sleeve.


and without Logos…..