In Malaysia R31 reverted back to the beam wing version with the lower arched centre zone , which was tested before season starts . In Australia the R31 chose to race with a taller design to maximize downforce production .
In Malaysia a metal joint was placed in the centre of the slotted tab to secure its stiffness . Excessive vibrations of an element ruins its aerodynamic or mechanic effectiveness and can even cause it to crack in some occasions .
The diffuser was again revised in Australia despite the latest upgrade at Barcelona test , having now a new slotted tab under the crash structure to let air bleed through . The pioneer of the slotted tab feature is credited to Toro Rosso and Renault is another team ( along with Red Bull and Mc Laren ) to copy this idea .
Renault seems to follow the same frenzy front wing development path like it did last season and launched a new front wing iteration in Sepang . The wing may had new endplates but the flaps remained though unchanged . The revisions are spotted on the front part of the endplate body which is now consisted of a single element instead of two with its base to be inclined outwards creating a large gap between its inner surface and the double profiled mini wing . The horizontal winglet is also gone while the outer low height vertical fence is new and features a deep cut on its lower rear part . All the changes focus to reduce turbulence around the outer front tyre surface .
Free practice sessions on Friday in Melbourne was an opportunity for Renault to evaluate R31 aero performance with the help of fluorescent paint . Renault was not the only team to experience fluorescent paint on their cars but Ferrari as well .
( for details on flow visualization paint check https://formula1techandart.wordpress.com/2011/02/20/red-bull-rb7-getting-green-at-jerez-february-test )
R31 splitter ( T tray ) sports high vertical side fences (No1) to create a channel over the splitter channeling air inside the bargeboard shield and around the side pod bottom . There is also an outer tunnel (No2) to improve airflow under the chassis towards the diffuser . To decrease vibration of this outer tunnel which affects performance negatively Renault in Melbourne used a metallic bonding (No3) to support the structure .
Heidfeld different driving style made him choose the larger brake ducts while Petrov the thinner in Melbourne . This is not something new for Renault as Kubica and Petrov in some occasions back in 2010 also raced different ducts suited of course to different front wing specs . However this time both drivers used the same front wing in Melbourne despite the different option on the ducts .