2005 Mid-Season Technical Analysis

With nine races done in a 19-race season, The Formula One 2005 World Championship is at the halfway point - a good time to take a look at how the regulations and the cars have shaped up in 2005.

The regulation changes, limiting teams to one engine per weekend, one set of tyres for the race and qualifying, and a drastic reduction in downforce, have been largely effective. Engine reliability has been impressive as has the rev ceilings and power outputs. Aerodynamic changes have produced the most varied set of designs for some years. In fact, only the tyre regulations have created a major stir - with first the decline of Bridgestone\Ferrari and then the catastrophe of the US Grand Prix.

After the early season surprise in the differing performances of the teams, the order hasn't remained static, with different teams producing upgrades at different races, making them jump their competitors on the time sheets.

McLaren and BAR were the slow starters and have since made up the deficit - and a lot more besides in McLaren's case. The leapfrogging could well continue throughout the year and see teams like Toyota, BAR and Williams take wins.

FIA Clarifications

Flexing Wings

Following on from the post-Bahrain clarification, and the new test designed to stop teams altering their rear wing geometry through flexing, the FIA have stepped in to further tighten up this exploitation.

This is not related to the stiffness of the wing assembly, to prevent it from wobbling around over bumps and the like, but it's intentional elasticity designed in to prevent drag from building up in fast corners and straights.

After Bahrain, the whole of the rear flap was subjected to a test to measure any deflection under load. Now the FIA rightly believes teams are making the rear edge of the main plane flex on the rear wing, and the flaps on the front wing.

They have announced new but undefined tests to apply loads to any aerodynamic surface, to ensure no deflection can occur, as required by the rules. While this may finally stamp out flexing wings, the flexing of other bodywork may also need to be included in the tests.

From the rear view camera it can be seen that, where the flip ups on the sidepods twist to form fences in between the rear wheels, flex occurs. Initially, this could be passed off as normal wobbling of the flimsy structures, but more careful analysis suggests that the vertical sections' direct flow to the rear wing at low speed make the rear wing more effective. Then, at higher speed, the sections open up and allow more flow to pass around the outside of the rear wing's endplate, reducing the rear wing's effectiveness and cutting drag.

As the current tests appear to centre on flex in a vertical axis, the flex of flow conditioners ahead of the wings could also soon be the subject of the FIA's attentions.

Ballast

Another clarification from the FIA has been the placement of ballast. Most F1 cars run from 60 to 80 Kilogrammes of dedicated ballast, which serves to make the car reach the minimum weight, but also to move the centre of gravity (CofG) downwards and front to rear.

The front to rear movement is part of the car's setup and is tuned for each track and even over the race weekend. The teams, who have been trying to place more weight over the front wheels to get the front tyres working better, now have less downforce to aid them.

To move the centre of gravity forward, they need to add more tungsten ballast towards the front of the car. As most of this exists within the aerodynamic floor and splitter below the driver's legs, there is little scope for moving much more weight forward. Adding ballast any further forward means raising the ballast up into the footwell - however this option moves the vertical CofG upwards, which is counter-productive to good handling. If they can place a smaller amount very far forward, the longitudinal CofG improves with less impact on vertical CofG.

Hence teams are starting to mount ballast in the detachable nosecone. This is strictly within the rules, but the risk of the nose cone being detached in an accident is high, and the heavy lump of tungsten subsequently flying around is a safety risk. The FIA have requested that this practice is stopped on safety grounds.

2005 Design Elements

Diffuser

With the 2005 aerodynamic changes slashing the downforce from the cars, the teams' efforts to regain the lost efficiency have required a different focus to that seen in recent years. With the underfloor design frozen for nearly ten years, diffuser design had been perfected, and only small incremental improvements could be found to yield more downforce. As a result, the aerodynamic teams were able to find gains on the more visible areas of the cars.

With a new set of dimensions to comply with, teams have had to complete a lot of work under the car to regain downforce. But why focus on the diffuser? Well, with the downforce cut by 25%, the teams need to increase downforce and not drag. Simply adding bigger wings would have worsened the car's efficiency (drag versus downforce).

Also, the recovered downforce would need to be apportioned front to rear to keep the balance. Fortunately the diffuser comes almost drag free, and the downforce it creates acts much further forward under the floor, placing it near the car's aerodynamic centre of pressure (the aero equivalent of CofG). This has seen the car's aerodynamics on the visible topside become less important, other than those developments made specifically to improve underbody airflow.

A diffuser works by having the expanding shape of the tunnels extracting air from under the car; this literally sucks the air under the floor, creating low pressure and hence downforce. Additionally, some ground effect is made by the tunnels themselves, but the downforce is generally at its highest at the leading edge of the floor. As the flow going under the floor is what makes the diffuser so effective, then so does the quality of that flow heading towards the diffuser. The diffuser wants a constant stream of undisturbed air, with lots of energy and no high pressure leaks coming from the top of the floor to underneath.

As teams now have to make the diffuser tunnels lower, and have a simpler (no undercut edges) design, more effort has to be put into making the tunnels work harder and improving the onset flow.

The tunnel designs are heading in several directions: Ferrari and now BAR make use of a small window (pictured yellow) in the dimensions to add a taller element to the side tunnel; Toyota have split the side tunnel into three for less leakage across the tunnel; and Red Bull and Williams have added winglets above the tunnel to produce some extra downforce. All teams adopt some form of Gurney above the diffuser and an extra flap in the centre tunnels leading from the plank.

Flow heading towards the floor is now conditioned by several devices: the sidepod fins, set low on the floor, have been almost universally adopted, as have the undercut sidepods, to prevent air spilling under the floor as it rounds the sidepods. In front of the rear wheels small fences and fins once again keep flow from passing under the floor and pressuring the diffuser.

Some convergence in design is likely, as teams have time to design and test the different solutions.

Front Wings

With the front wing being raised, its potential for creating effective downforce on outer thirds has been reduced. Furthermore, as the endplates are now in closer proximity to the wheels, the inward sweep and detailing of the endplates has altered.

Most teams have opted for wings that sweep down in the centre to gain the most from the lower ride height allowed across the 50cm central portion. Also differing between the teams is the length of the wing (Chord) across the span - the longer the chord, the greater the downforce and sensitivity to separation, while shorter, steeper chords are the reverse and create less drag.

Ferrari's solution could lead to more complex flows trailing in its wake and with it sensitivity, while McLaren's more organic design uses three elements to control separation and leaves harmonious flow off the wing, improving the effectiveness of the aerodynamics along the rear of the car.

Toyota, meanwhile, have sudden sharp changes in the wing's shape. This could potentially make the best shape for any given section of the wing, but the intersections can again give off unwanted turbulent flows, upsetting aerodynamics back along the car.

This year has also seen a distinct difference in nose shape and height. While most F1 designers have stated that the nose has little effect on aerodynamics, the shape of the nose and its proximity to the wing do have a real impact.

Renault's Bob Bell explains that the lower wider nose tips assist in making the car more balanced. Hence, Renault's and Williams' designed wings work unaided by a high thin nose, while Ferrari's and particularly McLaren's nose has a much greater interaction with the nose shape.

Endplates serve both to keep the top and bottom of the wing sealed and to send the flow around the inside of the front wheel and along the car in the best way possible. With the endplate raised along with the rest of the wing, the main design trends are for a cranked leading edge, making the upper half of the endplate more inline to the oncoming air and the underside (the suction surface, which is most important) as wide as possible.

The whole endplate generally sweeps in between the front wheels to reduce the wheel blocking the flow. The small flip-ups and cutouts on the outer face of the endplate have been simplified, the reduced gap between endplate and wheel diminishing their effectiveness.

Shoulder Wings and Closed Off Chimneys

F1 sidepods have almost universally evolved into a tall boxy front face, slimming dramatically down to the gearbox at the rear. This extreme coke bottle shape is great for creating low pressure above the floor to keep the diffuser happy, but the slimming shape actually creates lift, and as the sidepods are so small there is little scope to shape the flow to the rear wing. Two solutions have appeared to overcome these problems: shoulder wings and curved chimneys.

Shoulder wings first appeared on the Jordan last year. The broad wings high up on the front of the sidepod both add downforce in the middle of the car, which improves balance, and also as they are in the shadow of the sidepods - creating very little downforce. Also they send a jet of high-pressure air over the sidepods to feed the void created by the coke bottle shape.

Then, the chimneys serve to split the flow like a bargeboard over the sidepod. This Keeps the clean flow in line with the rear wing and sending the dirtier flow towards the winglets and flip-ups to be thrown around the outside of the rear wing. This is why they are kept on the car even if the temperature is cooler and the tops are closed off.

Team by team

Ferrari

The common perception is that there isn't much wrong with neither engine nor chassis; it's just that the tyres have not been working in the same harmony as in previous years. Ignoring the first couple of races with the interim car, which may well have been outclassed by purpose-built 2005 machinery regardless of tyre handicap, the team failed to qualify and start races well.

In the race, quite often the Ferrari cars have been at the same pace as the leading pack of cars - sometimes flashes of even greater speed have been seen; but even these have to be seen in the context of the leading driver with a large lead and under no pressure to put in fast laptimes.

In 2003, and even last year, the Bridgestone tyre didn't like the different demands of qualifying grip and race durability, using its construction to gain grip more than the chemical of the Michelin compound. Hence the Bridgestones run hotter and need to warm up before releasing their full grip. This theory is borne out by the Ferrari car's poor recovery from slow formation laps and safety car periods.

Compounding Ferrari's qualifying problem is the choice of heavier race fuel loads hindering their opening stints. Often it is not until the lighter fuelled cars are stopping that the Ferraris have really got the tyre up to speed and the fuel burnt off. By then the leader has a huge gap and only the clear track allows the Ferraris to catch up. The cars are at great risk by this stage, and the first corner incidents have tied both drivers at several races this year.

Unusually for Ferrari, this year they have also suffered from reliability and retirement issues. The gearbox is the weak spot on the car, seeing problems in practice for Rubens Barrichello, while his races have ended through tyre wear and hydraulic failures. Michael Schumacher's races have ended through a crash, hydraulic and tyre problems, resulting in a tally of five retirements.

The gearbox and its hydraulic system is one of the most complex systems on an F1 car, taking almost as long as the engine to develop completely new version. Ferrari's decision to slim the gearbox around the differential to create more space for the diffuser, pushed leads to the limit, and the lack of long term testing is still seeing its development done partly on the track.

BAR

The 007 car initially had aerodynamic inefficiencies as well as Honda engine problems. Development was initially slow as the team struggled to understand the car. Some bargeboard developments and the crash box wing were small additions, but only the reworking of the front wing changed the car's handling for the better.

This was unfortunately around the time the team were found guilty of cheating, with their car found underweight in San Marino. The two race and almost six week layoff allowed the BAR team to work on the car without having to run a Monaco wing package, and on their return at the Nurburgring the car was substantially changed, and again in Canada.

The complex trailing bargeboards were gone, replaced by simpler versions; then a new diffuser, rear wing, shoulder wings and flip-ups were brought out (pictured). The car's pace was improved, with front of grid qualifying from Jenson Button. But the car's race pace has yet to be confirmed, given the team's withdrawal from the US GP.

Married to the car's initial pace has been poor reliability, including two matched pairs of retirements with engine oil leak and clutch problems. To date, the Imola race from which the team were excluded remains their best on-track finish, with 3rd and 5th places.

Underlying the problems of the car's out-of-the-box pace, the ban and the US withdrawal, the team has potential to do well in the coming races.

Renault

Right from initial testing and going into the first races, Renault had a clear advantage. It seems their car was quick out of the box and while their rivals had problems with their cars, Fernando Alonso was able to make a break in the races and ease back to cruise to victory.

This advantage has proven to be slightly smaller than it first appeared - certainly they were managing their engine life very carefully, and for Giancarlo Fisichella at least the car had not proved totally reliable, with retirements caused by an engine failure, suspension failure and latterly a hydraulic problem.

With McLaren's resurrection, Renault have struggled in the most recent races, their qualifying paces dropping a little and the car less dominating in the races.

Renault have made quite a few changes to the car - the bargeboards, flip-ups and front wing endplates being the most obvious.

Although well balanced, it seems the car lacks downforce, hence the permanent addition to the bi-plane endplates to the front end. Furthermore, Renault were one of the teams rumoured to have added ballast to the nose-cone to add some load to the front tyres. With updates due over the next few races, we should be able to see if the car can get the Michelins working as well as McLaren have been able to do.

One other positive element of Renault's season has been the engine. This is the second year of the narrow angle (72-degree) engine, and its output is no longer a handicap for the team. They have been able to match the low drag aerodynamics to the greater power delivery to great effect. They have also not lost their advantage at the starts - Canada proving the torque engine and excellent control systems can do the job better than at other teams, with the advantage not coming from a rear biased weight distribution as with last year.

Williams

At the Williams launch in the beginning of the year, the car's problems were already known, and it was clear some procedural errors in the aerodynamics department left the team much catching up to do. By Melbourne, the team already had updates on the car and these would keep coming with extra flip-ups, modified engine cover, cooling outlets, wings and diffuser.

Adding downforce has been one of the team's greatest aims and the car has evolved into a very complex aerodynamic solution, with a lot of devices all trying to work at the same time. In comparison to its rival cars, the Williams is a work in progress that will no doubt become simplified as the small add-ons are designed in a more homogenous fashion.

Cooling has also been a concern for the team; the small radiators require large outlets and a hot running engine. The aerodynamic and engine problems now appear to demand a different solution, and it is rumoured Williams will use larger coolers within the same sidepods, and this should both cool the engine and allow for smaller and less draggy outlets.

The opening races have brought consistent finishes in the points, and only since Monaco has the car proved to be a real front row and podium threat. But with engine failures at two races, the exhaust valve problem experienced on Friday in Spain, and Nick Heidfeld getting a ten grid position penalty, show the engine is not totally reliable. This is allied to a still problematic system seeing poor starts at several races, compromising Mark Webber's generally high grid placing.

The second half of the season will no doubt see Williams further improve the car and challenge for wins, but already the Championship lead has moved too far. Perhaps a driver being in the top five of the Drivers' Championship and consolidating fourth in the Constructors' are reasonable targets for the car.

McLaren

Over the opening races, McLaren struggled with an uncompetitive car, but beneath the struggle it was clear the car had pace - during the last stints of the races the car was as quick as anything else on the track. It transpires that the car was too light on its tyres, failing to get the heat into them to allow the compound to work. This left both car trailing in the two qualifying sessions, leaving the drivers too much to do in the race.

After the flyaway races, McLaren were able to test more to get the best out of the car, and with Imola's engine upgrade and Spain's aero (crash box wing, pictured in yellow) and suspension update, the cars were back on the pace and the string of wins at Spain, Monaco and Canada finally the showed the potential of the package. On top of that, the car is now making much better use of its tyres than the opposition.

McLaren have often cited the matching of mechanical setup to the aerodynamics as a problem. This year the suspension revisions to the "no keel" front end seems to have got the tyres working better and not upset the aerodynamics.

However, to get the geometry correct McLaren have had to raise the lower wishbone and droop the upper wishbone to marry the upright to the chassis. Revisions to this geometry are what improved the car earlier this year, and McLaren's reliability has improved to: they suffered only one retirement from a mechanical failure (Kimi Raikkonen's driveshaft in Imola) - their second mechanical failure was primarily down to a driver error, when a flat-spotted tyre has lead to a wheel bearing vibrating to pieces, eventually wrecking the front suspension.

For the balance of the season McLaren seem to have everything in place to pressure Renault for both Championships. Continued development is a must, though, as the other teams will be bring major updates in the coming races.

Sauber

The 2005 car evolved from the C23 and grew more dramatic, with shrunken sidepods with deep undercuts at the front. Sauber's huge investment in wind tunnel and CFD computers seemed to have paid off with a first class aerodynamic design.

However, something was not well with the car at first testing and, of all things, aerodynamics were blamed. For Melbourne, some alterations were in place and over the season detail updates have appeared around the car, including new diffusers, wings, sidepods and cooling outlets. The latter element was not so much for cooling - as the car appeared in the hottest races without extra holes in the bodywork - but as a refinement to the aerodynamics.

The car has improved, but the team have yet to make the most of their tyres. Lowly qualifying positions forced the team into slower race strategies with heavier fuel and less stops. Also, tyres accounted for one retirement for Felipe Massa and cracked wheel accounted for another. Other technical failures have included two engine failures, one in practice and one in a race.

Aside from accidents, the only other cause for retirements was Jacques Villeneuve's problems with brakes at the start of the year - although this wasn't with the brakes per se but rather more to do with how the engine management takes control on the overrun. This changed how Villeneuve would expect the car to behave and meant this preferred brakes bias setting was wrong when the electronics cut in. However, with some work and a change to the general setup of his car, Villeneuve was soon more comfortable in the car.

With a strong platform, Sauber have the opportunity to do well in the second half of the year, chasing Red Bull Racing for sixth in the Constructors' Championship.

Red Bull

But in the opening races the package proved competitive and both drivers put in good races to score points. With the visual carry-over form the R4, the RB1 finally made good the philosophy put in place by the previous management.

Jaguar were only to race parts that were fully understood - that is, if a part gave an improvement, it wouldn't go on the car until the reason was proven. As a result, little changed on the new car, but the team had a good understanding of how it all worked.

Details changes around the rest of the car brought improvements in layout - such as torsion bars at the rear, and unique two pass radiators that send the coolant across the face of the radiator twice (front and rear). This is more efficient and neater to package, at the expense of some weight.

The new Cosworth engine has proven to be powerful enough with a major hike in power being declared for this year. The unit has been reliable as well - the only retirement coming from and electronics problem. The pace and reliability has left Red Bull in a good position in the Championship, but the switching of drivers has cost each of the alternating drivers a chance of the good Drivers' Championship finish and must affect the continuity of the car's development.

With another drivers' switch due, this time to coincide with the next major aero and engine update in France, Red Bull need to be careful to make to he most of their debut year in F1.

Toyota

Melbourne maintained the cause for doubts, but thereafter the team made the best of their tyres and points finishes at all tracks but Imola proved that the Toyota was a fast car and not just flattered by Jarno Trulli's qualifying runs.

In Spain, aero updates shortened the shoulder wings and floor fins, creating a design that will no doubt be copied by many other teams. Moreover, the car's aerodynamics have constantly improved the car's behavior over kerbs and bumps - a major leap from previous years. New rear suspension geometry and Sachs Radial Dampers have smoothed out the problems and only Imola's vicious kerbs upset the car.

Reliability has been excellent, with only the brake failure for Trulli in Canada stopping the car for technical reasons.

Toyota have been denying rumours of a B-spec car for several races; the official line is that there is no new car coming and not even a major aero update for France or Britain. I expect more small updates will continue to filter through to the race car and the engine, to be developed up to Suzuka.

Jordan

One of the last to run their 2005 car, the EJ15 is little than a revised EJ14 made to suit the Toyota engine and 2005 aero regulations. From seeing the car up close, it is clear the front and rear wings are 2004 versions re-sited to comply with the regulations; while the floor is new and a simple interpretation of the new rules.

But this simple package has been able to beat the all new Minardi, though not any other cars. With restricted resources to develop the 2005 car, development so far has been piece meal with small add-ons appearing every few races. These have included the chin added under the nose cone (shaded in image) and the fence (marked yellow) to keep flow over from spilling into the diffuser.

With a major update to the car coming in the next few races, the car will see some new aerodynamics and a revised gearbox without the spacer to make the old gearbox fit the Toyota engine.

Reliability has been a surprise, with only two technical retirements; in fact, Tiago Monteiro has finished every race this year - a unique achievement and a record for a rookie.

Should the update improve the car's pace, the best that can be expected is a move clear of Minardi, as the rest of the midfield are still too fast for the Jordan.

Minardi

Starting the season in a farcical demonstration against the FIA, the 2004 car was modified to the new rules. As expected, the cars languished at the back of the grid and the first of many gearbox failures halted one car.

After the flyaway races, the new car was ready and visually a major departure for Minardi from previous designs. However, the modern-looking car carried over its predecessor's gearbox, and the unreliability followed with it.

The improved aerodynamics and current spec Cosworth 90-degree unit have improved the car's pace - splitting the Jordans in qualifying.

Ignoring the Indianapolis result, however, the team have little chance of more points and could even lose sight of the Jordans in qualifying should the B spec Jordan prove to be an improvement.