2008 British GP Technical Review

Although Silverstone is a conventional circuit opening the second half of the season, the unusual conditions made direct comparisons between the teams difficult.

Much like Barcelona and Spa, Silverstone is typical F1 track, demanding good aero, power and mechanical grip. However the British summer is often blighted by rain and this year the free practice sessions and the race were affected by it.

The track layout is a clear split between new and old. The opening two sectors are all fast, flowing curves, rewarding the cars with well-balanced aero and drivable engines.

The closing sector of the lap is now a convoluted collection of tight turns before opening up onto the main straight. This sector is all about mechanical grip and balance.

The division between the two halves of the track compromises the car's set up. Thus the cars run high downforce, with a stiff front suspension set-up and a softer rear. This provides the control needed for the fast direction changes, but still bears grip in the last sector.

Silverstone does have some heavy braking zones, but they are interspersed with longer runs of light braking. Thus brake ducts can be small, improving aero efficiency.

In the race the wet start, which dried before the mid-race downpour, made tyre strategy tricky, particularly at the first stops, where the worn intermediates that had been working well up until the first stop were too worn after the stop to clear the rain that had started falling.

At the second stops the choice of intermediates or full wets was just as difficult. Both types of tyres did a surprisingly good job of lasting as the track dried towards the finish. In all three stints of the race standing water was the biggest issue; many drivers aquaplaned off the track, making the finish something of a lottery.

Ferrari

A bad weekend for Ferrari started before Friday, as Kimi Raikkonen's engine needed to be changed following the French GP exhaust failure. However as this was his first engine change of the season, it was allowed without a grid penalty.

The team's problems continued through practice, with Felipe Massa having a major shunt on Fernando Alonso's oil.

Later, both cars were suffering with power oversteer. Power oversteer is when the rear wheels slide uncontrollably in slower turns as the driver gets onto the throttle. Outwardly this looks like driver ineptitude, but is actually is much more a set-up issue. Suspension settings, weight distribution and tyre management are required to dial the problem out.

Toyota added a slot to the bridge-wing, allowing to be run at steeper angle © Scarborough (Click to enlarge)

Development-wise, Ferrari had a number of small updates on the car, the most obvious being a forward-facing fin on the bargeboard, akin to Toyota's solution.

Toyota

Toyota is still awaiting the 'revolutionary' developments referred to earlier this year and reiterated by Jarno Trulli after the French GP. Instead a more subtle development to the new front wing, already seen in France, was raced. The bridge wing element gained a slot on its outer spans, but the wing itself appears to be near-identical in shape to the non-slotted version used in France.

Honda

Ahead of suspension developments due in Hungary, Honda brought the first of two sets of major changes to the car's aerodynamics. In addition, Ross Brawn said there were new performance parts on the chassis and engine. These will be the last updates to the car for 2008 in order to allow development on the 2009 car.

The front wing has been revised, with new endplates and an all-new nose cone. The endplates now feature vertical leading edges, and no are longer dog-legged outward towards the footplate.

Meanwhile the nose cone, which used to be quite high at the tip, now features an extremely drooped tip. The changes are most likely aimed at making the car more consistent, rather than chasing more efficiency in terms of downforce or drag.

A new front wing assembly and 'heck' wings were used on the Honda © Scarborough (Click to enlarge)

At the back of the car, the T-wings have been revised to mimic BMW Saubers 'heck' wings, with their inboard edges extending to meet the engine cover. This set-up replaces the shelf wing fitted between the flip-ups and works to feed the flow to the rear wing.

Force India Ferrari

While other teams produced reasonable update to their cars, Force India produced a major upgrade. Although not touted a B-spec car, the changes were almost as substantial. They mainly affected the aerodynamics, but also the suspension with the debut of an inerter at the front of the car.

Aerodynamically the car gained almost all new surfaces - the front wing, sidepods, top body and diffuser. Force India's technical director James Key told Autosport.com about the changes.

According to Key, the front the wing is "a deeper centre section main plane and flap. This is the first iteration of this wing package and more development will be carried out in the coming weeks."

The flow from the front wing passes over unchanged bargeboards towards the sidepods. Externally these are all new, based around a new cooling exit philosophy.

"The cooling is now controlled by louvered bodywork rather than chimney exits, allowing the chimney surfaces to be used for aero development," Key explained.

"The side pod leading edge wing is new and complements the new louvered cooling exits and chimney modifications. The primary changes to the top body are the cooling exits; this has allowed the side pod wing, chimney profiles and Z600 (T-wings) to be used and developed together."

As part of a major upgrade, the Force India engine-cover and sidepods were changed © Scarborough (Click to enlarge)

The result has been a pod wing, chimney and T-wing all merged into one long continuous surface. Such a long run of bodywork may adversely affect the car in yaw (a tail slide).

"The yaw performance is being looked at now and will likely result in further changes," Key said. "We have new parts around the side pod wing for the next race."

Above the new sidepods is a shark-fin engine cover. As with other teams this was primarily aimed to improve stability, but could be prone to side winds and blocking the rear wing in yaw.

"The engine cover did help with stability; there has been little sensitivity to cross winds to date," Key said. "It is important to tune the trailing edge of the fin for the rear wing to ensure that it is not adversely affected in yaw as suggested; in fact some features of the fin seem to help the wing in yaw."

Lastly, Force India's non F1-like openness is typified by its admission of running an inerter (J Damper) for the first time.

"The inertia damper was first run in the Silverstone test and required further tuning for this weekend," Key said.

"We came to the race weekend with a different configuration and some set-up options after looking at the data from the test. These seem to have worked well for general car stability, although further optimisation is required at this stage."

As most teams rarely run a front third damper, there may be problems for teams to package a slightly larger inerter inside the nose of the monocoque. For Force India, Key feels this was not an issue: "We had provision for a heavier damper, so fitting a front inertia damper was not a problem."

Four elements on the front and a tiny sidepod inlet were part of McLaren's Silverstone package © Scarborough (Click to enlarge)

McLaren Mercedes

Following developments in France, McLaren continued its updates to the car. These very visual changes are not normally a trademark of the team's in-season development, and suggests that the team is pressing very hard to develop the car, and needs to make bigger changes to keep up its targeted 0.2s improvement per race.

Silverstone's updates on the McLaren were focussed around the front wing, the diffuser area and sidepod inlets.

It's front wing now sports four elements in the lower wing - this is unusual in F1, and combined with the bridge wing, the outer tips have six profiles in cross-section. Most teams are now running a three-element front wing plus a bridge wing to produce the forward biased downforce that the Bridgestone tyres need.

McLaren is clearly able to exploit even more front-end downforce. This would need to be balanced either by more rear downforce or a more front-biased weight distribution. The former scenario appears likely, as the diffuser was revised in France and in Britain gained some new fins attached to the rear brake ducts.

McLaren was late to use the rear brake duct area to fit extra vanes, and its interpretation of the brake duct fin uses a horizontal fin with turned down edge. The fin works with the flow exiting the diffuser to create more rear downforce.

In France we saw a smaller sidepod inlet for the right-hand sidepod; in Silverstone the team used an even smaller opening. No doubt aided by the cooler ambient weather and the lack of an oil cooler in that sidepod, the new opening was no more than a horizontal slot.

This would send less flow through the radiator, which in turns requires less outlet area. The diverted external flow is sent around the sidepod to create a faster flow over the top of the diffuser, and would actually increase rear downforce.