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Scarbs blog

Spring-Less Rear Suspension – A Quiet Revolution

In the latter part of the year suggestions were that teams were discarding the rear side springs to allow very soft rear ends. This has proved to be the case, in the past few years teams have been removing their rear torsion bars to gain greater control of suspension set up. This revolution has been quietly spreading as many teams have gone this route.

An early sign springs were being removed was the I-Racing game, which accurately modeled the FW31 with the Williams teams assistance, the game provided no scope for rear springs. Equally comments made by Anthony Davidson over the Abu Dhabi Grand Prix weekend suggested that McLaren’s extreme stiff front\soft rear was due to this set up. Leading to Buttons problems locking up the inside wheel under braking. Closer investigation with technical people close to the sport prove this to be case and the practice is widespread amongst several teams, already McLaren and Williams are highlighted as adopting this practice, but Toyota and red bull are sporting this set up, by virtue of their gearbox supply this suggests that force India and Toro Rosso have the option too. Although this seems to be a relevantly recent practice as most teams first designed this into the 2009 cars, albeit it may have been tested or raced before then.

Suspension on F1 cars has the joint purpose to control the cars attitude both for aerodynamics and tyre dynamics. These often contradictory requirements have lead to compromises, largely against tyre performance and more to the benefit of aero control. Aerodynamicists want the car to run flat (or raked) with little change in roll or ride height. For mechanical grip the car needs softer attitude control. This has lead F1 cars to run quite stiff front ends and softer rear ends, both in roll and heave. A soft rear ARB creates more mechanical grip, which then in turns needs to be controlled by a stiff front anti roll bar. For aerodynamics reasons the front wing and splitter like to be flat to the track surface to gain most downforce, thus this also tends to require a stiff anti roll bar.
At the extreme end of this set up characteristic this has been exhibited most clearly in McLarens handling. The car gains traction from the soft rear anti roll bar, but the stiff front roll bar means that the rear heavy car tends to roll at the rear and this picks up the inside front wheel going into turns.
On a side point although McLaren run what has been called a stiff front axle, their apparent problem with grip over bumps going into turns is not necessarily a reflection of this set up, more that the cars aero requires tight ride height control, it is possible to run stiff anti roll bar and still have a compliance for coping with bumps.

Heave is when the car moves vertically, thus both wheels are rising or falling together
In a typical rear suspension the effect of heave is that the heave spring (blue) and each side spring (yellow) is providing stiffness. The dampers (Red) damp the motion.

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Roll is when the car tilts, thus one wheel is rising and one is falling
In a typical rear suspension the effect of Roll is the ARB (orange) and the side springs provide the stiffness. Again, the Dampers (Red) damp the motion

[Imagen: 2em34vn.jpg]
Single wheel bump, which tends to be for riding kerbs or bumps in the track is a secondary requirement to heave and roll control, spring rates are not normally tuned for this requirement, instead the cars dampers allow freer suspension movement when the wheel suddenly rises up at a greater rate than normal, the damper has different rates for the wheel rising at different speeds, known as low speed (the cars chassis moving slowly i.e. pitch roll) high speed (bumps) and often a tertiary setting known as ‘blow off’ where the damper will provide a far lower damper rate for extreme wheel speeds such as kerbing.

Hence in both heave and roll the side springs are providing additional stiffness to the effective spring rate, thus both roll and have are coupled to the rate of the side springs. If we can do away with the side springs then both roll and have can be totally independent and controlled by their relevant springs. If you need a softer ARB rate, then the side springs are the limiting factor.

[Imagen: wweogn.jpg]
When you do away with the side springs, the heave and roll bar rates are higher in order to replace the spring rate added by the side spring. As long as each of these devices has a wide enough range of springs then there is no loss in control.

[Imagen: xfxnad.jpg]
It’s noteworthy that both rear dampers are used, in the nineties we saw monoshock front ends, which utilised both a single spring and single dampers. But monoshocks only have one damper so the control of roll is undamped. With a side spring-less set up there’s two dampers, controlling roll motion. Which is an obvious improvement in vehicle control over Monoshocks.
Although there are some set backs with a side spring-less set up, some suspension designers want a non linear rate to the heave and wheel rates and sometimes different rising rate curve for each of these elements. This is achieved by the linkage (pushrod or pullrod) and the rocker geometry, going for side spring-less set up prevents having differing wheel and heave spring rising rates. In some engineers opinions, this is the removal of a needless layer of complexity.
A heave element not only supports the rear axle heave motion, but the element provides a non linear rate. Ground clearance is used up through downforce compressing the suspension as speed increases. The heave element has a range of free movement, this is taken up as ride height lowers until the then the heave spring itself (or Belleville stacks or bump rubbers) come into effect and add considerable rate to the heave motion. This prevents grounding or choking the underfloor through low ground clearance.
Equally making set up changes is both simplified and complicated. Engineers can now change either roll or heave rates independently, before changing a changing torsion bar effectively altered both. But changing a torsion bar, while not a quick task was the switch of an isolated component. Now teams will need to change the entire heave spring or ARB assembly.
An additional benefit is if a team wants to commit fully to the side spring-less set up, the packaging of the suspension becomes far easier, no longer having to package long torsion bars. This is perhaps a reason why Red Bull were able to effectively package the pullrod set up, as the pivot for the rocker is near vertical, fitting a torsion bar in this position would have been be tricky.

With the design of next years car leading towards a widespread adoption of pullrod, the option to adopt side spring-less will be attractive to aid packaging. Although the side spring-less pushrod set up will also allow dampers and rockers more freedom to be packaged at the front of the gearbox casing. Adoption at the front of the car is possible too, there is lesser need as the front roll rate is higher and the torsion bars can add to the effective rate. But simpler packaging and tuning may still be attractive for a designer
[Imagen: 27wsxfk.jpg]

Fernando es de otro planeta

Lo pongo esperando que algun experto nos lo explique
[Imagen: 27wsxfk.jpg]

Fernando es de otro planeta
(09-12-2010, 16:13)maripi escribió:

Lo pongo esperando que algun experto nos lo explique

Pues yo mismo lo explico.
Viene a decir que si esas suspensiones las lleva el McLaren o el Redbull, son legales, pero si se las ponen a Alonso no.
¡Avanti, Fer, AVANTI!

[Imagen: corea2010.jpg]
(09-12-2010, 18:47)Salvaje escribió:
(09-12-2010, 16:13)maripi escribió:

Lo pongo esperando que algun experto nos lo explique

Pues yo mismo lo explico.
Viene a decir que si esas suspensiones las lleva el McLaren o el Redbull, son legales, pero si se las ponen a Alonso no.

Eres un prodigio de la traducción, Salvaje.


Finally the FIA have published the detail of the 2011 technical regulations. There were no major surprises amongst the rules. There being rules to effectively ban: double diffusers, F-ducts & slotted rear wings. Newly introduced were the mandated weight distribution and adjustable rear wing.
There’s a lot to cover, so I wont cover every rule change and neither can I cover them in detail. but here’s the main points (with the rule in italics).

The full FIA regulations are detailed here: FIA F1 2011 Technical Regulations

Ban on connected shark fins
Another route to banning F-ducts, as well as a move to limit the ever expanding rear fin, the rule prevents any bodywork reaching the rear wing.

“3.9.1 No bodywork situated between 50mm and 330mm forward of the rear wheel centre line may be more than 730mm above the reference plane.”

Ban on slots in the beam wing

With the exception of the central 15cm, the beam wing cannot have a slot that widens internals to create a blown slot. Only Williams raced this last year, but the practice has prevented. This reinforces the fundamental rule that the lower wing should only be formed of one element

“3.10.1 Any bodywork more than 150mm behind the rear wheel centre line which is between 150mm and 730mm above the reference plane, and between 75mm and 355mm from the car centre line, must lie in an area when viewed from the side of the car that is situated between 150mm and 350mm behind the rear wheel centre line and between 300mm and 400mm above the reference plane. When viewed from the side of the car no longitudinal cross section may have more than one section in this area.
Furthermore, no part of this section in contact with the external air stream may have a local concave radius of curvature smaller than 100mm.
Once this section is defined, ‘gurney’ type trim tabs may be fitted to the trailing edge. When measured in any longitudinal cross section no dimension of any such trim tab may exceed 20mm.”

Ban on slots in the rear wing

As with the beam wing, the upper rear wing is prevented from having slots extending beyond the central 15cm. This prevent F-ducts or other blown slots, the latter which have been exploited for several years.

“3.10.2 Other than the bodywork defined in Article 3.10.9, any bodywork behind a point lying 50mm forward of the rear wheel centre line which is more than 730mm above the reference plane, and less than 355mm from the car centre line, must lie in an area when viewed from the side of the car that is situated between the rear wheel centre line and a point 350mm behind it.
With the exception of minimal parts solely associated with adjustment of the section in accordance with
Article 3.18 :
- when viewed from the side of the car, no longitudinal cross section may have more than two sections in this area, each of which must be closed.
- no part of these longitudinal cross sections in contact with the external air stream may have a local concave radius of curvature smaller than 100mm.
Once the rearmost and uppermost section is defined, ‘gurney’ type trim tabs may be fitted to the trailing edge. When measured in any longitudinal cross section no dimension of any such trim tab may exceed 20mm.
The chord of the rearmost and uppermost closed section must always be smaller than the chord of the lowermost section at the same lateral station.”

Limit on Rear wing support pylons

The number, thickness and cross-section of the rear wing support pylons are now more tightly controlled.

“3.10.9 Any horizontal section between 600mm and 730mm above the reference plane, taken through bodywork located rearward of a point lying 50mm forward of the rear wheel centre line and less than 75mm from the car centre line,
may contain no more than two closed symmetrical sections with a maximum total area of 5000mm2. The thickness of each section may not exceed 25mm when measured perpendicular to the car centre line.
Once fully defined, the section at 725mm above the reference plane may be extruded upwards to join the sections defined in Article 3.10.2. A fillet radius no greater than 10mm may be used where these sections join.”

Clarification of the starter motor hole

After some teams were exploiting oversized starter motor holes in the diffuser to create a slotted effect, the FIA clamped down with a clarification. This has now been written into the rule book.

“3.12.7 No bodywork which is visible from beneath the car and which lies between the rear wheel centre line and a point 350mm rearward of it may be more than 125mm above the reference plane. With the exception of the aperture described below, any intersection of the surfaces in this area with a lateral or longitudinal vertical plane should form one continuous line which is visible from beneath the car.
An aperture for the purpose of allowing access for the device referred to in Article 5.16 is permitted in this surface. However, no such aperture may have an area greater than 3500mm2 when projected onto the surface itself and no point on the aperture may be more than 100mm from any other point on the aperture.”

Ban on Double Diffusers (DDD) and Open Exhaust Blown Diffusers (EBD)

Due to a previous weakness in the rules defining the underfloor, teams were able to exploit this to create the double diffuser. Double diffusers were only possible as an opening could be created in the gap been the reference plane, step plane and the diffuser. Now the rules close this avenue off.
Additionally this opening allowed teams to open up the front of the diffuser to blow the exhaust through for an even greater blown diffuser effect. This rule also prevents this opening in all but the outer 50mm of the split between the diffuser and the floor.
One additional clarification is that the suspension must not form any of the measured point for the under floor. Previously the minimum height was exploited by some teams placing wishbones or Toe-Control arms across the top an opening in the diffuser.

“3.12.9 In an area lying 450mm or less from the car centre line, and from 450mm forward of the rear face of the cockpit entry template to 350mm rearward of the rear wheel centre line, any intersection of any bodywork visible from beneath the car with a lateral or longitudinal vertical plane should form one continuous line which is visible from beneath the car. When assessing the compliance of bodywork surfaces in this area the aperture referred to in Article 3.12.7 need not be considered.

3.12.10 In an area lying 650mm or less from the car centre line, and from 450mm forward of the rear face of the
cockpit entry template to 350mm forward of the rear wheel centre line, any intersection of any bodywork
visible from beneath the car with a lateral or longitudinal vertical plane should form one continuous line
which is visible from beneath the car.
3.12.11 Compliance with Article 3.12 must be demonstrated with the panels referred to in Articles 15.4.7 and
15.4.8 and all unsprung parts of the car removed.”

Driver operated F-duct
Even though the loop holes in the rear wing regulations have been closed, this additional new regulation prevents the driver influencing aerodynamics. So that other driver controlled F-duct type devices cannot be exploited other areas, such as: front wings, sidepods or diffuser.

“3.15 With the exception of the parts necessary for the adjustment described in Article 3.18, any car system, device or procedure which uses, or is suspected of using, driver movement as a means of altering the aerodynamic characteristics of the car is prohibited.”

Ban on movable splitters

As with some other rules, this is a 2010 clarification now added to the regulations. Its thought that teams were allowing their splitter to flex upwards, to allow the car to run a more raked attitude and lower front wing ride height. There are now more stringent tests and restrictions on the splitter support mechanisms.

“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 articulatio
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.”

The driver adjustable front wing is now deleted from the rules and instead the rear wing is now driver adjustable. This is because the expected benefit of greater front wing angle never provided the driver with more grip when following another car. The front flap adjustment was much more a solution to tune the cars handling in between pitstops. The TWG found that the loss of drag from the rear wing was a more effective solution to allow the following to overtake. Now the rear wing flap can pivot near its rear most point and open the slot gap from 10-15mm to up to 50mm. Opening this gap unloads the flap and reduced both downforce and drag.
This being controlled by the timing gap to the car ahead and managed by the FIA. So there’s two ways the driver can use the system. Firstly in free practice and qualifying the rear wing is solely at the control of the driver. They can adjust the wing at any point on the track and any number of times per lap. So for the ideal lap time, as soon as the car is no longer downforce dependant (straights and fast curves) the driver can operate the wing, just as they did with the F-duct. Although a small complication to the driving process, at least their hands remain on the wheel and not on a duct to the side of the cockpit.
Then in the race the wing cannot be adjusted for two laps, then race control will send signals to the driver via the steering wheel, such that when they’re 1s or less behind another car at a designated point on the circuit, the rear wing can be trimmed out. The wing returns to the original setting as soon as the brakes are touched.

“Furthermore, the distance between adjacent sections at any longitudinal plane must lie between 10mm and 15mm at their closest position, except, in accordance with Article 3.18, when this distance must lie between 10mm and 50mm.”

3.18.1 The incidence of the rearmost and uppermost closed section described in Article 3.10.2 may be varied whilst the car is in motion provided :
- It comprises only one component that must be symmetrically arranged about the car centre line with a minimum width of 708mm.
- With the exception of minimal parts solely associated with adjustment of the section, no parts of the section in contact with the external airstream may be located any more than 355mm from of the car centre line.
- With the exception of any minimal parts solely associated with adjustment of the rearmost and uppermost section, two closed sections are used in the area described in Article 3.10.2.
- Any such variation of incidence maintains compliance with all of the bodywork regulations.
- When viewed from the side of the car at any longitudinal vertical cross section, the physical point of rotation of the rearmost and uppermost closed section must be fixed and located no more than 20mm below the upper extremity and no more than 20mm forward of the rear extremity of the area described in Article 3.10.2 at all times.
- The design is such that failure of the system will result in the uppermost closed section returning to the normal high incidence position.
- Any alteration of the incidence of the uppermost closed section may only be commanded by direct driver input and controlled using the control electronics specified in Article 8.2.
3.18.2 The adjustable bodywork may be activated by the driver at any time prior to the start of the race and, for the sole purpose of improving overtaking opportunities during the race, after the driver has completed a minimum of two laps after the race start or following a safety car period.
The driver may only activate the adjustable bodywork in the race when he has been notified via the control electronics (see Article 8.2) that it is enabled. It will only be enabled if the driver is less than one second behind another at any of the pre-determined positions around each circuit. The system will be disabled by the control electronics the first time the driver uses the brakes after he has activated the system.
The FIA may, after consulting all competitors, adjust the above time proximity in order to ensure the stated purpose of the adjustable bodywork is met.”

Mandated weight distribution

Along with the supply of Pirelli control tyres they will be matched to a mandatory weight distribution. Now the cars minimum weight is 640Kg, the specified minimum axle weights, equate to a weight distribution ranging between 45.5-46.7% on the front axle. This is a few percent behind the typical 2010 loadings.

“4.2 Weight distribution :
For 2011 only, the weight applied on the front and rear wheels must not be less than 291kg and 342kg respectively at all times during the qualifying practice session.
If, when required for checking, a car is not already fitted with dry-weather tyres, it will be weighed on a set of dry-weather tyres selected by the FIA technical delegate.”

Double wheel tethers

For safety a doubling of the wheel tethers has been regulated. Each tether needs to pass through a different suspension member and have its own mounting points on the upright and the chassis. There’s not expected to be any performance impact with this. But the tethers are somewhat heavier, so they and the side intrusion panel are part of the reason for the greater minimum weight limit.

“10.3.6 In order to help prevent a wheel becoming separated in the event of all suspension members connecting it to the car failing provision must be made to accommodate flexible tethers, each with a cross sectional area greater than 110mm². The sole purpose of the tethers is to prevent a wheel becoming separated from the car, they should perform no other function.
The tethers and their attachments must also be designed in order to help prevent a wheel making contact with the driver’s head during an accident.
Each wheel must be fitted with two tethers each of which exceed the requirements of 3.1.1 of Test Procedure 03/07.
Each tether must have its own separate attachments at both ends which :
- are able to withstand a tensile force of 70kN in any direction within a cone of 45° (included angle) measured from the load line of the relevant suspension member ;
- on the survival cell or gearbox are separated by at least 100mm measured between the centres of the two attachment points ;
- on each wheel/upright assembly are located on opposite sides of the vertical and horizontal wheel centre lines and are separated by at least 100mm measured between the centres of the two attachment points ;
- are able to accommodate tether end fittings with a minimum inside diameter of 15mm.
Furthermore, no suspension member may contain more than one tether.
Each tether must exceed 450mm in length and must utilise end fittings which result in a tether bend radius greater than 7.5mm.”

No more shaped wheel spokes

After the static front wheel fairings that abounded in 2009, were banned and the wheel design homologated, there must have been some surprise that Ferrari managed to create an aerodynamic wheel shape in 2010. This is partly limited now by the restriction on surface area for spokes and shaping. The limited only allows 13% of the wheel centre to be spoked, meaning that a ten spoke wheel has to have spokes just 16mm wide.

“12.4.6 When viewed perpendicular to the plane formed by the outer face of the wheel and between the diameters of 120mm and 270mm the wheel may have an area of no greater than 24,000mm2.”

Clarification of mirror positions

Again when the FIA clarify a rule or make a change for safety reasons, we don’t get to see the detail of this change until its put into the regulations. The removal of outboard mirrors was brought in early last year and now the mirrors can effectively be no more than 27.5cm from the cockpit opening

“14.3.3 All parts of the rear view mirrors, including their housings and mountings, must be situated between 250mm and 500mm from the car centre line and between 550mm and 750mm from the rear edge of the cockpit entry template.”

Ban on blade roll structures

Mercedes surprised many with their blade-like roll structure, reducing the obstruction to the rear wing and allowing for a much shorter inlet tract for the engine, the solution was likely to be copied. A minimum cross section forced teams to have a wider section above the drivers head, negating the fundamental benefit of the solution

“15.2.4 The principal roll structure must have a minimum enclosed structural cross section of 10000mm², in vertical projection, across a horizontal plane 50mm below its highest point. The area thus established must not exceed 200mm in length or width and may not be less than 10000mm2 below this point.”

Dash roll structure point maximum height

With the cockpit opening fixed at 550mm, teams have often raised the front of the chassis around the dash bulkhead to create a raised nose. In the first of several limits for both 2011 and 2013, with even more stringent plans for 2013, the height of the front of the chassis is now being controlled. The limit for this point is now 670mm, still some 120mm above the cockpit opening.

“15.2.3 The highest point of the second structure may not be more than 670mm above the reference plane and must pass a static load test details of which may be found in Article 17.3.”

Limit on front chassis height

As already explained teams raise the position of the front (AA) and dash (BB) bulkheads to create space under the nose for airflow to pass in between the front wheels and reach the rear of the car. The trend for “V” sections noses, introduced on the Red Bull RB5 in 2009, makes the front of the chassis even higher, often being visible above the height of the front tyres (~660mm). Now both these bulkheads need to be at 625mm, some 75mm above the cockpit opening.

“15.4.4 The maximum height of the survival cell between the lines A-A and B-B is 625mm above the reference plane.”

Limit on shaped Rear Impact Structures

Since the 2009 aero rules, teams have been shaping the rear impact structures into ever more curved shapes to lift it clear of the diffuser and pass it underneath the beam wing. The tail of this structure must be centred at 300mm high, to prevent extreme banana shaped structures, this rule forces the structure to vary by no more 275mm.

“Furthermore, when viewed from the side, the lowest and highest points of the impact absorbing structure between its rear face and 50mm aft of the rear wheel centre line may not be separated vertically by more than 275 mm.”

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Fernando es de otro planeta

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[Imagen: 27wsxfk.jpg]

Fernando es de otro planeta

2011 Winter Launch and Test Schedule
with 3 comments

Team Engine Car Date Location

Red Bull Renault RB7
Ferrari Ferrari Project 662 Last week of January
McLaren Mercedes MP4-26
Mercedes Mercedes W02
Renault Renault R31 Last week of January
Williams Cosworth FW33
Force India Mercedes VJM04
Sauber Ferrari C30 Monday 31st Jan (11.15 CET) Valencia
Scuderia Toro Rosso Ferrari STR6 Tuesday 1st Feb Valencia
Team Lotus Renault T128
Hispania Racing Team Cosworth F111
Virgin Racing Cosworth VR02 Not until Jerez test

Valencia February 1-3
Jerez February 10-13
Barcelona February 18-21
Bahrain March 3-6

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Fernando es de otro planeta

Ferrari F150 – Launch detail & Analysis
with 7 comments

Ferrari launched their F150 today in Maranello. While the car sports some interesting features, overall it must be seen as a conventional and literal approach to the new rules and carries the influence of the team’s two previous cars. This approach seems to suit Ferrari who has not worked well with extreme innovation in the past. They keep the car simple and gain the most potential from it. We can expect more extreme concept cars from several teams next week.

[Imagen: 20uv7dl.jpg]
Firstly the front wing is last years; it even has the driver adjustable mechanism which is no longer allowed in 2011. However the nose cone will be fairly definitive, as it needs to match the front of the chassis and being a homologated part, cannot be structurally changed during the season. This front wing may be on the car for the opening test runs, but we will soon see an interim 2011 wing before a final version appears for Bahrain.
One by-product of the new rules restricting front chassis height is that a V-nose might not be desirable. As the height of the dash and front bulkheads are limited to a maximum height, the “V” nose might be inefficient. V-noses allowed more flow under the car without putting too much heavy structure high up. Now to maximise space under the nose we might see a return to the simpler rectangular chassis cross section, with the top edge at the 670mm limit, which creates the most space underneath. Thus the Ferrari has a near flat top and the line from the cockpit opening rises up 45mm from the dash to the front wheels.
The section of chassis attaching the suspension (subjectively) appears to longer. Access hatches on the top of the chassis allow access to the pedals, heave spring and GPS aerial. Otherwise the front wishbone arrangement appears conventional, with the steering rack placed lower than the upper wishbone for better CofG and steering arm geometry.

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Aero around the front end is largely carried over from 2010, with vanes hanging from the nose cone then larger bargeboards and pod wings mounted ahead of the sidepods. We can expect these to change in detail before Bahrain, Relatively simple mirrors are fitted and mated to a fin\vortex generator below. Similarly the roll hoop is a simple design, not as undercut as others. The sidepods themselves are an evolution of ideas from the past two years. The inlets have been made into a more distinct sideways “U” shape and the distinctive peak above the inlet is still there. This peak is now allied to a small removable panel, what this is for is not clear. As it appears the radiators are further back down the sidepod, following the same line as the break in the forward and rear section of sidepod bodywork. The panel might be for a cooling outlet, but perhaps for smaller oil\KERS coolers mounted alone in this area. The revised sidepod inlet creates a more aggressive undercut, although the sidepod has to be relatively wide (between the Shell and Acer logo) for the radiators to fit between the fuel tank and bodywork.
Sidepods then sweep into a coke bottle shape with a generous hot air outlet at its tail, this rear opening also houses the exhausts that blow over the diffuser. The top body no longer sports a shark fin; a simple upstand is used in its place, although no doubt the fin may return in testing. As was raced last year the bodywork either side of the fin opens up to allow cooling.

At the back the rear wing is a new departure for Ferrari, the entire wing is mounted to the central pylon, and then the beam wing spans the endplates and sits fully expose din the airflow. It’s been Ferrari practice to split the beam wing either side of the crash structure for many years. The top rear wing is new, with the mechanism to allow the wing to open the slot up apparently inside the wings supporting pylon. The curved bracket protruding from the pylon moves up and down, probably by hydraulics fed up from the gearbox, to alter the wings flap position. Its possible to see the how the flap pivots via pins set into the flap trailing edge. A distinct “V” has been cut into the flaps trailing edge, probably to reduce its effective geometry, as it sits in airflow obstructed by the engine cover and wing adjusting mechanism.
With very few detailed of the diffuser, it appears its a very simple diffuser which echoes the single decker design Ferrari first raced with in 2009. No doubt the gurney, inner fences and boat tail will alter as the team gets more performance from the diffuser.
Being careful not to read too much into the cars launch specification the front wheels appear to be based on the 2010 vaned versions. New rules specify a maximum surface area for spokes and other similar parts of the wheel. Perhaps the narrow spokes make up for the surface area taken up by the vanes.
One item raised by Ferrari was their innovative suspension system, not the pull rod system that many expected, as the car boasts push rods at both ends. But Ferrari were rumoured around the pit lane to have run an interconnected suspension system last year. The front and rear suspension being linked to control the cars attitude. This could either be to control pitch (the nose rising or lowering through acceleration/braking) or warp (a mix of pitch and roll). Apparently used by Toyota and Williams without success in the past, this passive system could aid aerodynamics by keeping the underfloor in the correct attitude relative the track.

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As double diffusers are banned the advantage to inclining the engine and gearbox by 3-degrees is lost now, so we can expect the engine is again mounted horizontal. With engines Frozen, the only changes are reliability alterations (with the FIA’s permission) or changes to accommodate KERS. Ferraris engine man Luca Marmorini announced more changes to the engines pneumatic valve system (PVRS). This area was changed after reliability problems last year in the early races. Marmorini, who came back to Ferrari from Toyota, is thought to have brought ideas for a more efficient PVRS system with him. Worth not only reliability, but a increase in performance through lower friction and less engine degradation over the course its 3-4 races. The KERS system places the MGU offset from the front of the crank and attached to the oil tank, as the unit is cooled by the engines oil. The oil tank is quite large and Ferrari are suggested to also run another tank above the clutch within the gearbox.
The KERS battery pack is mounted inside the monocoque under the fuel tank (not within the actual tank and petrol!). As the batteries are denser than fuel this keeps a low CofG, already most teams have several centimeters of space under the fuel taken up by blocks of ballast, rising the fuel tank by an equal amount. One area Ferrari were clear that they have improved KERS on this year is the way the MGU charges when the car brakes. Marmorini stated this was improving the “dragging” of the system.
Little word has been made on the gearbox, Ferrari have adopted a titanium skeleton with bonded on carbon fibre panels for several years. Aside from the packaging of the pushrod suspension, this is expected to be largely carried over this year.

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2011: Trends and Solutions

A reworking of a 2010 car, legal to the 2011 rules

A 2010 car for comparison

We’ve already covered the rule changes for 2011. Over the late part of last year and the winter, the teams have been finding ways to regain the performance lost through the new rules and how to maximise the new tyres. I’ve put forward an idea of a generic 2011 F1 car. Admittedly based its on the RB6, but as that car has a lot of the feature we can expect from a 2011 car, this is mainly for convenience. I’ve also speculated on what workarounds or innovations as some call them might be. It seems designers are now working with other engineers on one hand and lawyers for interpreting the rules on the other. There’s bound to be other ‘innovations’ aimed at finding solutions to circumvent the rules intention, it will be interesting to see what the teams have found to be the new double diffuser or F-Duct for 2011.

Layout and weight distribution
The cars layout will inevitably be hit by the Pirelli tyres and mandated weight front to rear distribution. The weight will be shifted a few percent rearwards, this will provide the teams a chance to alter the cars layout, shifting the major masses towards the rear axle. Most likely the gearbox will be shortened, having been extended to maximise the double diffuser last year. So for the first time in several years, super short ‘boxes will be in vogue. Curiously USF1’s idea for super short transverse box, might be attractive for an innovative team.

Additionally the rearwards weight bias, no longer rewards super light and of course expensive carbon gearboxes. Although as with any part on an F1 car, lighter weight components simply create more ballast available for tuning the cars set up.

To maintain wheelbase, the teams can either extend the front of the chassis or extend the fuel tank length. The former will be good for aero and making the vanes around the front work more effectively. While the latter solution will be attractive as KERS will eat up crucial fuel tank volume.

KERS & Cooling
In our Generic 2011 car (above) I’ve shortened the rear and extended the front, retaining the same wheelbase. To maintain Fuel tank volume, rather than mount KERS battery pack under the fuel tank, I’d suggest it goes in the right hand sidepod, as McLaren did in 2009. Sitting at floor level in the wake of the lower side impact protection beams, this should not impact sidepod volume or undercut. Albeit at a small cost in CofG height, as many teams will still prefer to fit the battery pack under the fuel cell, as the 10-15kg battery is denser than fuel the CofG is lower and the batteries safely out of the way. Also helping retain fuel volume, could be Hondas idea of mounting the Motor Generator on a series of gears, to shift it from the front of the engine and into the sidepod area.

With the KERS Power Control Unit in the left-hand sidepod, this needs an air inlet as the electronics are air-cooled. The Battery pack is water-cooled from its own pump and radiator in the right-hand sidepod. The Motor Generator is oil cooled from the existing engine oil system. The engines oil cooler is mounted atop the gearbox and fed from ducts either side of the roll hoop.

Also on the cooling side, the radiators reach right to the very front of the sidepods, nestling in the side impact protection. The also frees up sidepod\fuel tank space, and beneficially allows an extra cooling outlet at the front edge of the sidepod. One of the few legal areas for cooling outlets. Additional cooling outlets to the side of the cockpit and at the tail of the upper engine cover are used, as they vent hot air close the front of the sidepod, this reduces the sidepod volume required to route the air to the rear of the coke bottle shape. Slimmer sidepods force better airflow over the diffuser for more downforce.

Diffusers, Exhausts and Gearboxes
Another aid to the flow over the diffuser is the shape of the gearbox. This is largely dependant on the teams philosophy, Red Bull reintroduced Pull rod suspension at the rear of the car. This is likely to be the much talked about shift in concept for other teams. Pull Rod is lower, but wider. Push Rod tends to be taller and narrower, but mechanically has a higher centre of gravity. I doubt there’s a significant gain from either system.

With either suspension system, the smaller “single deck” diffuser will not encroach into the volume taken up by the gearbox. Thus designers can make the gearbox and in particular the heavy differential, much lower. This creates a easier path for airflow to the beam wing and usefully lowers the CofG. However Red Bull took this approach in 2009 and suffered some driveshaft issues as the angularity of the CV joints was on the limit of their design.

A practice first exploited by Red Bull was the lowering of the rear wing endplates down to floor level. This is a loophole in the rules, as although the wing is narrower than the diffuser, the additional rear overhang increases the expansion ratio of the diffuser, effectively making the diffuser longer than its meant to be. Williams and Toyota also exploited this idea in 2009 albeit using the full width of the diffuser too.

Blowing the exhaust over the diffuser will be exploited by all teams. This will be most easily done by having low exhausts, blowing onto a gurney on the top or side of the diffuser. The rules demand two exhaust outlets, so multiple exhausts are not allowed, equally blowing into the diffuser is not supposed to be allowed. The only openings in the diffuser are the starter motor hole and a 5cm area on the outer section of floor.

Exhausts could be routed to this outer section of floor, but routing the large diameter exhausts across the floor could create their own blockage effect in-between the rear wheels. Offsetting the benefit they are supposed to provide.

However, the starter motor hole could be exploited! If the left and right exhausts were joined and then split into a upper and lower exit, one smaller exit could blow into the starter motor hole, the other exhaust would blow over the top of the beam wing, allied to a big gurney flap. This meets the two exits and no-opening rules. The exhaust routing might be a bit tortuous though.

Rear Wings
Above all this the rear wing has no scope for active or passive f-ducts, the driver adjustable wing effectively makes those solutions redundant anyway. As rear downforce will be lost from the diffuser, the rear wing will need to recoup some of the losses. The middle 15cm of wing are still free for additional slots and wing profiles. So we can expect the usual slots and perhaps the mini winglets normally only seen a high downforce\high drag tracks.

One innovation could be to use this mount for this winglet and perhaps the rear wing support pylon as continuations of the shark fin. As the fin must not extend behind the rear wheel, equally the rear wing may not reach any further forward than before. With a rear wing fin the flow off the truncated shark fin could reattach to the RW fin. Regaining some of the yaw control and flow straightening effect of the longer 2010 style shark fins.

Front Wings
At the sharp end the front wing no longer needs to be quite as powerful, as it only needs to create downforce to balance that available at the rear, in doing so matching the ‘centre of pressure‘ to within 1-2% of the mandatory weight distribution.

Front wing designs have converged towards the downturned ends of the wing creating the endplate, then a remote vane being fitted to direct flow around the front wheel and also meet the FIA minimum surface area for bodywork ahead of the front wheels.

As McLaren found in 2010, the cascade can be split to encourage flow either side of the front wheel. Many team started to play with camera mountings, to place them aft of the Dwg7 neutral centre of the wing, This is likely to be a feature for many teams front wings, to create a little bit more wake-friendly downforce.

As regards flexibility, we saw obvious deflection on cars front wings last year. These met the both the original and uprated FIA deflection tests. Thus a precedent has been set that wings that are seen to flex, remain legal as long as they meet the deflection tests. Thus most teams will be looking at the composite lay up of the front wing to allow the vertical deflection test to be passed, with the wing then deflecting with the compound load (both longitudinal and vertical) seen when on track. It’s a concern that teams will have to exploit this to remain competitive. There’s a risk of wing failures, as teams find what the structural demands are for a aero-elastic wing.

Front wings have merged into the endplate, Cascades aim to split flow around front wheels

A variety of solutions improve flow the rear wing and reduce sidepod volume

Sidepods are crammed with the water radiator to boost fuel tank size

To accommadate KERS Sidepods need space and cooling for the Batteries and Control Unit

Rear wings connected to the shark fin are banned, but a fin on the RW may be allowed

Double diffusers are banned, maximising the blown single diffuser will be critical

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