McLaren car updates: Launch to Hungary

McLaren's 2010 contender already looked pretty well developed even at its launch, but as usual the team have developed their car at an impressive pace, a very needed move after they had discovered that their car was lagging behind the Red Bull and Ferrari.

F-duct

Nevertheless, as of the beginning of the season, the McLaren featured a new rear wing stalling device which most other teams tried to copy later on in the season after initially struggling to understand the system.

Numerous revisions occurred from launch time to the first 2010 race at Bahrain but the teams' innovative rear wing stalling system ( called also as F-duct ) caught all the attention. This system uses a nose duct atop of the monocoque (at the F letter of the Vodafone logo) to receive airflow.

Winter test	Winter test version where part of the inlet is covered by a carbon fibre panel	Bahrain

The airflow is directed via a tube inside and around the cockpit, crossing the engine cover before finally ending at hole located on the centre zone of the rear wing profile. Airflow then exist on the backside of the rear wing through a small additional pair of wavy shaped slits.

The air entering this tube could be blocked by the drivers left leg and at the same time stall the rear wing, as the exiting airflow detaches the laminar flow at the rear face of the wing. The system is much complicated and the team tested various versions before launching it at Bahrain. The visual variations are spotted on the nose snorkel and are the following.

The driver at will can block the air feeding the rear wing at straights, causing the rear wing to stall and gain a significant greater top speed for the MP4/25 up to 7-12 km/h, depending on the tuning of the system and the track characteristics. The system was found to be within the rules by the FIA.

GP Bahrain

Updates from launch

• New nose snorkel (F-duct) at Jerez, 19-2-2010
• New nose snorkel (F-duct) at Barcelona, 25-2-2010
• Elongated sidepod panels at Barcelona, 27-2-2010. Now connecting directly to the floor's turning vanes and offer a better airflow around the sidepod bottoms
• Revised exhausts – rear zone at Barcelona, 26-2-2010
• The team tested multiple configurations of hot air exits during winter tests
• Modified diffuser at Bahrain
• New simpler front wing at Barcelona 28-2-2010, retained for Bahrain GP

Front wing

1. Modified movable second flap mechanism
2. New simpler bargeboards, having two holes
3. The additional winglets span is now reduced as they do no longer extend over and out
   of the endplates
4. The air fin stabilizer is now rejected

Diffuser

Launch	Bahrain

• The horizontal section does not feature a tab anymore
• The side section upper wall has now an extended tab (fence)
• Larger hole to access the motor starter
• The central section upper part has a parallel to the ground line shape.
• Additional slit
• The rectangular slot is now closed
• Double connection elements of the wing's endplates to the diffuser
  upper wall instead of single.

Rear floor vent (duct)

Bahrain and Barcelona

The team added a duct (in yellow) in the floor of the rear tyres. This duct, which was first introduced at Barcelona's winter test, improves the quality of the air directed into the diffuser's side channels, boosting the downforce production.

GP Australia

The revision for the Australian GP sports revised front wing end plates, the hot air outlets on each side of the cockpit were removed and the asymmetric hot air exhausts made their return in light of reduced cooling needs. The diffuser was changed to comply with a regulatory request by the FIA.

Apart from these minor updates, the team were also testing two different sets of mirrors, an inboard and an outboard set. At that time several teams were trying out outboard versions, trying if their aerodynamic benefit was worth the reduced visibility.

Front wing

McLaren was forced by the FIA to revise the front wing endplates at Australia for safety reasons as their edges (in yellow color) were found to be too sharp.

Australia	Bahrain

Diffuser

Apart from the front wing the team had to change the diffuser as well as it was found to be in breach of article 3.12.7 of the technical regulations.

Article 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 175mm above the reference plane. 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. A single break in the surface is permitted solely to allow the minimum required
access for the device referred to in Article 5.15.

In plain words, McLaren ran a larger than needed hole to access the engine starter to make its diffuser act partially as a triple decked instead of two-decked, gaining extra downforce.

GP Malaysia

More changes came at the burning hot Malaysian race with the team to take extra care to satisfy the car's cooling needs. It is also worthy of saying that the strong Mercedes engine and the efficiency of the F-duct gave the McLaren wings to reach top speeds no other car could rival.

• Slots on both sidepods instead of the only one at right used at cooler Melbourne
• A gilled vent was present only at left cockpit side
• Symmetric rear bodywork around the exhaust pipes instead of asymmetric
• Small revisions to the diffuser
• Revised floor extension under the nose , with extra side air guiders and modified frontal surface.

Floor extension under the nose

Launch	Malaysia

The new redesigned floor features a side additional vent to guide the air more effectively under the car.

Diffuser

Australia	Malaysia

The modified diffuser spec used at Sepang had smaller tabs (1) to increase slightly the pressure on the sunction side and a redesigned side pointy extension (2) to offer a better air circulation close to the inner rear wheel zone.

GP China

The major revisions occurred at Shanghai were related to the car’s cooling once again. In China cooling needs are less than Sepang and therefore McLaren ran a car version similar to Albert park with less outlets for the hot air to decrease drag in favour of top speed. Among those changes as assymectric sidepod bodywork around the exhausts, the removal of the gilled sidepod vent used at Malaysia and using a sidepod vent above the cooling entry only on the left hand side.

Rear bodywork

China on Friday	China on Sunday	Malaysia

At China a symmetric rear end was tested but the team finally chose to race with asymmetric bodywork, similar to the one used at Melbourne with an enlarged outlet around the left exhaust pipe. Why asymmetrical? because the majority of the MP4/25 electronics and the oil tank are housed inside the left sidepod thus a better cooling option is needed for the left rear end. In hot races like Sakhir and Sepang the need for cooling is a top priority , but for cooler conditions like Melbourne and China an asymmetric rear hot air outlet option (with the rear end outlet to be smaller) is selected as the cooling demands of the right sidepod are less. It is obvious that smaller outlets offer less drag.

GP Spain

The majority of teams brought major revisions to their cars at Catalunya, the first European race for the 2010 season, and so did McLaren in order to find some extra downforce and improve overall aerodynamic efficiency. In with the new package are a new front wing, a new diffuser and the new rear wing.

The team did keep the same cooling configuration as the asymmetric exhaust bodywork was identical to that used in China.

Front wing

China	Bahrain

At the front the new endplates now feature a modified double vented combo, with the second one to be taller and its opening divided by a horizontal splitter, in an attempt to improve airflow around the front tyres and to increase the quantity of air passing under the car. Moreover the upper triangular fin is now flatter and shorter while the rear end of the endplates now feature a round and protruding profile to divert airflow away from the tyres frontal surface. Lastly the front wing adjusting mechanism and the adjustment points to set up the front wing had to be relocated to comply with the new end plate.

Rear wing

At the rear a new rear wing was introduced with revised planes and a new connection of the F-duct system's tube to the wing. There is now a wide inlet in the middle of the main plane and two additional smaller ones on either sides. This combination of inlets provide with air a slot extending up to all the wing's width that help to improve laminar flow on the back side of the rear wing at high angles of attack. As a result the F-duct system's tube connection point to the wing is now moved further up and shoots air through the modified slot at the backside of the wing. Finally the endplates feature less slots to reduce air bleeding out of the wing favouring downforce production.

Pre-Spain vs Spain	Monaco

GP Monaco

Monaco hardly saw any car updates on the McLaren, despite its very high downforce requirements.
Apart from its traditional diamond marketing campaign where it puts a diamond on steering wheels and driver helmets, there was only a minor revision to the diffuser.
McLaren was also the only team to run an F-duct at Monte Carlo as the MP4/25 was designed from the start to operate with its F-duct.

China	Spain	Monaco

The new diffuser 'Renault'-style which was deployed at Catalunya had an additional new winglet under the light, new shaped central zone, additional flaps and a completely new inner structure. At Monaco a minor revision (increase to the tab fence) to the pointy extension took place

At race the team mechanics forgot to remove the cooling cover left on the left-hand sidepod from Button's car and he experienced a disappointing and frustrating retirement a few laps after the start due to engine overheating.

GP Turkey

Once again McLaren brought significant changes at Turkey like a new rear wing to favour top speed, new sculpted sidepod panels and a new set of winglets located at the rear wheel’s inner upper zone, an area where all the 2010 cars feature multiple winglet sets.

Rear wing

At Turkey McLaren changed from a high downforce rear wing to a Turkey specification with a higher leading edge that droops down on the outer extremities of the wing, a design element McLaren have used extensively on rear wing in recent years. Along with the move, the added central extra slot (in the middle 20cm of the wing) was removed as it was focussed on downforce increase, whereas the Istanbul circuit mainly requires lower drag.

Finally there was also a new blowing slot of reduced length of the F-duct system, placed lower.

Pre-Turkey (Spain)	Turkey

Sidepod panels

Turkey	Pre-Turkey

The revised sidepod panel now has a trapezoid shape for mainly two reasons. First it decreases the distance between the panel and the sidepod to increase air speed by using the venturi effect between these two rigid elements. Secondly the curved panel creates a channel on its outside. Simply put, it attempts to seperate airflow in two, one part flowing at the bottom and another one guided through this channel around the sidepod's middle section. This new panel formation improves the quality and quantity of air flowing towards the rear of the car. It is worthy of reminding that the lower streamline of air around the sidepod bottoms, which is now improved, interacts also with the diffuser side section via the small vent in front of the rear wheels.

Diffuser

Pre-Turkey	Turkey

At Turkey the central zone's wall's have a new upper part and the pointy side tabs were once again revised on a constant seek for the ideal flow of air through this zone.

GP Canada

McLaren had a surprisingly unchanged package at Canada, leaving its front and rear wings entirely unchanged, despite lower downforce requirements.

One small update was a revision to the F-duct, allowing the car to gain a little extra top speed and thriving Hamilton to the win.

GP Europe

Again a few changes occurred for McLaren ahead of the major improvements coming at Silverstone. Those changes were actually focusing on managing heat issues, so a symmetric rear bodywork configuration was adopted for the slower and hotter Valencia street circuit, replacing the former asymmetric one. Along with the modified bodywork, it was found that McLaren removed the slots on the front upper sidepod.

The most striking update for the car is the operating system of the F-Duct. Before the European GP, the McLaren drivers had to cover a hole in the cockpit with their left knee to active the duct and reduce drag. After Ferrari introduced their version by positioning the hole to be operated by the driver's left hand, McLaren changed their system, as the hand operation appears to be the driver's favourite. We can guess that the former knee operated system was chosen initially by the team due to secrecy reasons as it could not be easily noticed.

GP Great-Britain

The MP4/25 had a new front wing at Silverstone, along with a return to asymmetric rear exhaust bodywork and slots on both sidepods to help cool the car. The most important change on the car was however the introduction of the long awaited blown diffuser as the team relocated the exhaust pipes to low above the floor.

McLaren did not manage to race the new upgrade package brought at Silverstone due
to insufficient proper track testing. Martin Whitmarsh even admitted the task to race the new blown diffuser package was bigger than they expected to be. The team mainly had problems with heat management at Silverstone as suspension arms are directly within the exhaust airflow.

The new package consists of :

• New floor placed exhaust system outlets to directly feed and energize the diffuser with hot gases
• New floor
• New rear bodywork and sidepods, much slimmer and compact towards the rear end
• Modified diffuser to cope better with the blown diffuser philosophy
• Additional rear heat coverings for extra protection
• The rear’s suspension lower wishbone had a large heat cover for extra protection

Front wing

The new front wing featured a new vertical flap splitter mounted on the main flap and onto a point located at one third of the total main flap length and close to the endplates. This splitter, which now houses the wing adjuster - allowing the end plates to be lighter - divides not only the main flap into two sections but also the upper cascade element.

The main flap has also a new wavy profile, curving upwards towards the new vertical panel and the outer end plate. Along with the wing itself, the end plates were also revised to manage airflow towards the new blown diffuser. They feature a longer upper triangular fin, new second slot which is not divided into two anymore and a more sealed rear surface with a much smaller cut.

Old spec	New spec

GP Germany

Germany marks the race debut of the blown diffuser on a McLaren, albeit with some revisions compared to the original package presented at Silverstone. A gilled vent was added above the air inlet of the sidepod while shark gills were added above the lowered exhaust, again only on the left hand side.

Exhaust blown diffuser

The team finally managed to race the new rear end package with the exhaust blown diffuser design. The system raced at Germany was not identical to the one initially tested at Silverstone but instead the exhaust pipes and the bodywork around them were modified.

Silverstone	Germany, 1st version, only tested. Small changes to the lower wishbone and also the bodywork was cut around the exhaust pipes	Germany, 2nd version , used at race. Elongated cut of exhaust pipes

The team actually tested two versions of the system, one with cut of bodywork around the pipes outlet to low down the temperatures in this area and another one with elongated pipes which were cut off to permit a stronger interaction with the air coming around the sidepod bottoms. The second version featured also an additional piece of carbon around the pipes. At race the team chose to use the cut of pipes.

Along with the lower exhaust, the sidepods were also provided of shark gills to provide cooling. Both cars ran with shark gills on both sides of the car on Friday, but the team eventually decided only the gills on the left side would be enough for the race.

Diffuser

The new diffuser first tested at Silverstone alongside with the new exhaust blown diffuser package, has a new more boxy central zone with a new hole to access the engine starter, much shorter side walls and a curving downwards upper element to cope better with the new blown diffuser philosophy.

Under the diffuser and on the inner large wall surface we can observe blue colored stripes. That is because the diffuser is coated with new heat protective paint to prevent shape deformation observed during free runs at Silverstone.

Silverstone	Germany

GP Hungary

The MP4/25 featured enlarged rear bodywork with a large rear end hot air outlet and smaller extra outlets in front of the suspension's upper wishbones. The team also re-used the Spanish/Monaco rear wing spec for additional downforce at the twisty track while small revisions to the lower wishbones of the rear suspension marked further tweaks for the low exhaust exit.

Germany - race version	Hungary

The near rear central hot air outlet is amazingly larger than the old version and also the gills were replaced by new symmetric smaller outlets. The new outlet is so large that we can even observe the internal suspension elements under the engine cover.

Rear suspension

Germany	Hungary

The rear suspension lower wishbone was once more revised with the heat covering protective element to be wrapped only around the outer part of the wishbone located just above the exhaust pipe. The second solution is preferable as it is lighter and it was allowed by the fact that the elongated exhaust pipes blow the hot emissions only under the outer lower wishbone area.