At slow and high downforce Hungaroring the team brought back the rear wing spec firstly presented at Spain which produces greater amount of downforce .
At Canada it was surprising to see Mc Laren keeping its Turkish rear wing version as teams traditionally reduce the rear planes chord in favor of achieving top speed at long straights. For sure Mc Laren’s revised F-duct system launched there helped the team to sustain a good top speed .
The rear wing introduced at Turkey regained the pre-Spain main flap profile with the leading edge at the central section to be raised up so as to divert more air under the planes (drag and downforce reduction by this configuration ). Furthermore the second flap had its chord being lengthened at its central section to gain some of the lost downforce . Apart from the former mentioned, the endplates slot-gills were also increased in number just like before the Spanish race .
Furthermore the wide inlet in the middle of the main plane and the two more additional smaller ones on either sides were rejected and as a result of it the second plane lost its additional slot at its rear surface in favor of a single shorthened one . Finally there was a new blowing slot of reduced length of the F-duct system, placed lower.
The new rear wing design is not “new” for Mc laren as it was extensively used during the past years time and it replaced the maximum downforce rear wing used at Monte Carlo . The new wing may produces less downforce but significantly less drag .
At Spain 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 (yellow arrows ) . These combo of inlets provide with air a slot extending up to all the plane’s width ( in white No 1 ) and help to prevent wing’s stalling in high speed and high attack angle . As a result the F-duct system’s tube connection point to the wing is now moved further up and shoots air to a modified also slot ( in black No 2 ) , placed above the previous mentioned one .
Lastly the endplate itself featured less slots to let less air bleed out of the wing favouring downforce production .
Mc Laren’s rear wing features the following major characteristics :
1.The main profile is bending upwards in its middle to divert airflow under the wing and not over, in an attempt to reduce turbulence around the connection point between the shark fin and the plane .
2.Single pillar to ensure wing stiffness
3.At the top of the endplate, there are multiple shark gills
4. Endplates have a deep cut at their rear upper part . That cut helps to reduce drag
5. Gurney tab , differs from the rest red plane as it is in black color
Mc Laren constructed its 2010 condenter , the MP4/25 , equipped with a new innovative system , called the F-duct which helped the car to achieve higher top speed at straights without loosing downforce at corners .
Official name of the system :
While press and media called the system “The F-duct” , Mc Laren officially coded the system as “RW80” meaning Rear Wing version 80
What is the benefit from such a system :
The driver at will can blow a high velocity airstream to the rear wing at straights , causing the it to stall , gaining a significant greater top speed for the MP4/25 up to 7-12 km/h according to the tuning of the system and the track characteristics . The system was found to be within the rules by the FIA .
Why the system was considered to be legal :
Several teams protested against the legality of the system when it gained publicity but FIA had already gave the green light to Mc Laren to develop such a system because the non movable-flexing wing plane principle is not violated as the system alters only the airflow around the wing and not the wing’s flexibility . Rival teams rushed to copy the system with the first one to be Sauber , while Ferrari , Red Bull , Williams , Force India and much later Renault and Toro Rosso also launched their own versions of the system .
For 2011 the rear wing stalling system was ruled out of the regulations in favor of the new rear wing attack angle adjustment mechanism .
How the system is activated :
The air entering the nose snorkel can be blocked by the drivers left leg at will and as a result the airflow inside the engine cover is forced by changed pressure to circulate via a certain tube to reach the rear wing causing it to stall .
Parts of the system :
The system functions with the combination of three different air inlets which are :
(A) a nose duct ( spotted where the F letter of the Vodafone logo exists and so called F-duct ) – (Number 4 )
(B) an inlet located behind the driver’s helmet under the primary airbox inlet to receive airflow – (Number 3 )
(C) airbox second upper inlet – (Number 1 )
[The number 2 inlet feeds the engine with air and has nothing to do with the system]
The received airflow from the nose duct is directed via a tube inside and around the cockpit ending inside the engine cover . There it meets a second richer airflow coming from the (B) inlet. The summoned airflows then enter a system of tubes housed inside the engine cover . The airflow coming from the (C) airbox upper inlet also enters this system of tubes
How the system functions :
When the system is active ( at driver will ) the airflow entering the (C) airbox inlet circulates via a certain tube , gaining gradually velocity with the help of a venturi effect , to reach a hole located on the centre zone of the rear wing profile ( yellow arrow ) . The airflow hits the wing and exits behind the wing’s profile via a small additional pair of wavy shaped slits , disrupting airflow and causing the wing to stall . As a result the wing’s drag production is significantly decreased in favor of top speed .
wing blown aiflow exits behind the wing’s profile via a small additional pair of wavy shaped slits
When system is inactive the air inside the engine cover flows into a second tube exiting above the beam wing leaving the rear wing unaffected .
Pre-2010 season variations of the system :
The system is much complicated and the team tested various versions before launching it at Bahrain . The visual variations regarding the nose snorkel are the following .
Developments during 2010 season of the system
During season Mc Laren developed further the system . The season developments regarding the system’s activation way ,which was revised from driver’s knee to driver’s hand and the different system’s tuning and air exiting ways , are going to be described in future posts .