Another update that took place for STR6 before Melbourne can be found on the rear , located on the diffuser area . The main diffuser’s structure remains though unchanged but with the addition of two more vertical fences close to the centre tunnel focusing on extracting more efficiently air flowing under the floor and close to the plank ( skid block ) . A major change took also above the diffuser with the tab flap to be totally new and being consisted of a single element rather than two . Between the tab and the diffuser roof there is a significant gap , larger than the previous design and extending up to the venturi channels to increase air bleeding through favoring further drag cut . The tab finally features pointed extensions close to the wheels , a feature shown by Mc Laren in the past , to cut turbulence in this crucial area .
Last year teams were trying to divert more air through the diffuser channels to boost downforce , while this season facing the ban of the multiple deck diffuser, teams follow a different route by accelerating airflow above the diffuser roof leading to more complicated (Williams) and even slotted tab flap designs ( Red Bull , Toro Rosso , Lotus Renault ).
Some of the methods being used to accelerate airflow over the diffuser roof is the twin floor shown by Toro Rosso , the special hot air exiting by Lotus Renault , Williams and Red Bull , the ultra slim sidepods and gearbox by Red Bull and finally the special exhaust blowing by Mercedes GP, Ferrari, Mc Laren , Force India, Williams , Lotus , Marussia Virgin and HRT
An interesting diffuser concept with complex central zone for STR6 but in fact not new for Formula 1 in general . Toyota , Williams and Sauber in the past raced similar multiple central channels to increase effective diffuser volume and also change the way airflow exits from the centre and the way it mixes with the air coming over the diffuser to cut drag . As for the diffuser’s roof tab , is divided into two sections , one outer and one inner slotted to let air pass through ( in blue arrows ) decreasing drag further .
Apart from the centre zone the side tunnels have several vertical fences of different length to help extract air under the floor more efficiently preventing flow detachment creating less turbulence . Diffuser is possible to undergo changes , changes that would be probably triggered by the way exhausts blow the hot emissions to the rear .