Formula One car development blog

A closer look onto Toyota's diffuser
Toyota look to be back where they were early on in the season, close to the front runners. After a mid-season struggle, the team introduced several updates that shaved a few tenths off the car's pace. Currently, Toyota's TF109 is running with a double deck diffuser much alike that of Brawn or McLaren with a downward bend in the centre. Previously the double deck diffuser had a design similar to Williams' initial design, but the Japanese team quickly understood the advantages of the improved concept once other teams came around to race with it.
Interesting is also the bottom end of the rear wing endplates. It basically is an improved version of Red Bull's long endplates, adding small openings and curves to extract air from the inside of the panel to the outside, hence adding downforce. The outside of the diffuser also features a small winglet, pushing air up just like the diffuser pulls it up.
Finally, also marked with an arrow is the position of the lower wing element of the rear wing. Toyota modified the rear end of the car to allow a free airstream under the wing, a concept the Red Bull RB5 featured already at the Australian GP.

Force India introduce outboard mirrors
Outboard mirrors are more and more becoming the standard, and Force India is now jumping on the bandwagon by replacing its inboard mirrors - connected to the cockpit sides - with mirrors fixed on top of the sidepod panels.
BMW Sauber is one of the teams to have made the same design change during this season. Renault on the other hand are using conventional inboard mirrors after having introduced this type of mirror positioning on their Renault R27.

Red Bull design new diffuser for RB5
Red Bull Racing have brought another aerodynamic step to its car at Singapore, and most notably that includes a new diffuser. The new design has changed mostly in the centre part of the car, around the double decked area. Where the older version focused on speeding up air on the lower channel, the new iteration has a bigger central channel around the crash structure to profit more of the DDD design. The central part is now very similar to the Renault or Brawn diffusers.
One detail marked in the image however are two small pointy extensions on both sides of the diffuser. Red Bull carefully copied that from McLaren and clearly found the additions efficient enough to use them.

They finally made it, a real front wing endplate
Ever since the beginning of the season, actually even during winter testing, BMW Sauber have been running extremely bulky and simple front wing endplates. At first we thought they were just for testing purposes, but the items stayed there far too long, until the Singapore GP.
There, the F1.09 was raced with a far more complex endplate, much resembling the Brawn GP and Force India versions. The combination of two panels with a separate vertical element to support the stacked elements helps divert air around the front wheels while not spilling too much air flowing over the top of the wing.

A particular shark fin on the Force India
Force India is clearly not standing still after their recent successes at Spa and Monza. At Singapore, the team introduced a shark fin, replacing the car's conventional engine cover used throughout the season so far.
The new fin connects to the rear wing, just like at Red Bull, although Force India's version features a large opening ahead of the rear wing to control its unfluence when the car is under yaw. The change immediately appears to have made the stacked centre of the rear wing obsolete, an item that was used at Valencia to increase downforce.

McLaren continue use of extended sidepod panel
Already used in Belgium, McLaren have continued the use of their new extended sidepod panel at Monza. Before the event at Spa-Francorchamps, McLaren were basically the only team who did have a sidepod panel that was not attached to the car's floor.
Brawn also recently switched to this design type as it offers better rear end stability of the car. Since they have used it also at higher downforce circuits, it is expected that McLaren's design is not only for low downforce configurations of their car either.

Force India revise sidepod panel
Along with their aerodynamic update at the European GP in Valencia, Force India introduced an updated version of their sidepod panel. More specifically at the top end of the panel, airflow is now possible in between the fence and the sidepod's shell. Previously, this area was part shaped as a splitter to divert air around it.
The new version helps Force India to reduce the car's drag, while the little winglet lower down on the panel still helps downforce at the rear by creating a high energy vortex. A similar vortex generator can be found on Toyota's car.

Brawn GP experimenting with shark fin
Brawn GP have brought a shark fin engine cover to Spa, resembling much to Renault's version. Jenson Button drove it on Friday for quite a few laps, but the team eventually decided not to race it. We may however see it again on future tracks this year.
Another point of interest in this image is the rear wing adjustment possibility. As earlier posted, Williams opted to have the trailing edge lower than the maximum rear wing height. Brawn on the other hand always have the maximum height and adjust the rear wing's angle of attack by moving the leading edge up or down.

New stacked panel on Red Bull front wing
Despite its medium downforce setup that the circuit of Spa-Francorchamp requires, the high speed corners still demand a fair amount of front downforce. Red Bull have taken this quite literally and have introduced a new front wing, or at least a new upper element on the wing.
While it as previously one continuous element, a small vertical fence now seperates the inward side - still unchanged - and the outward side which has a much larger angle of attack than before. The modification resembles a similar design change that Renault introduced on its Renault R28 before winning two races with Fernando Alonso.

Williams use lower rear wing at Spa
Spa-Francorchamps is the first medium downforce track on the 2009 calendar, so teams are coming up with smaller rear and front wings to reduce drag and increase top speeds. Williams for one is special, as it didn't only make its rear wing smaller, it is now also lower.
The arrow in the image clearly shows that the main flap is not extending to the maximum height - which is the upside of the end plate - by a few centimeters below. The solution puts the wing slightly more behind the car's body and hence creates a little bit less drag.
The idea itself isn't new and has already been used by Honda last year.