Silverstone was bound to be the weekend where the FIA clamped down on blown diffusers, as it aimed to limit the use of off-throttle exhaust blowing. Teams lobbying to try to get an advantage has made this into a very troubled regulation change.
Although Charlie Whiting earlier noted that the FIA does not really changes the regulations, but instead wants to stop teams from breaking the rules, off-throttle blowing has never been forbidden before, and hence engine manufacturers rely on the system for various purposes.
Renault for instance have claimed for weeks to run a similar method to provide exhaust valve cooling.
Immediately after the FIA announced to clamp down on the off-throttle blowing, teams started lobbying in an attempt not to be disadvantaged. Initially this resulted in the FIA allowing Mercedes to keep firing half its cylinders off-throttle to ease crank pressure. This was allowed after Mercedes, as engine manufacturer, claimed it needed more than the agreed 20% off-throttle flow to maintain reliability of its engine.
This in return triggered the Renault powered teams to ask for an exemption as well, motivated by their need to cool the exhaust valves.
That concession however didn't please Martin Whitmarsh, noting that it's hard to work when regulations are changing in the middle of a race weekend, or even in the middle of a session. Along with Christian Horner, Red Bull Racing's principal, they eventually agreed it would have been better to keep things as they were and wait for a regulation change until the end of the season.
Ferrari though were happy to let the other teams discuss, as it is quite obvious the Italian cars were not using the off-throttle blowing technique a lot, or at least not as extreme as some other teams were doing. Along with several car updates, this resulted in the Ferrari's taking place on the second row for the British GP, and more importantly edging close to the times of the Red Bulls.
At day's end, the FIA however decided to release yet another announcement. Charlie Whiting and his team decided that if all teams agreed, it would revert the whole diffuser clampdown before the German GP.
There is obviously a lot of opposition from teams against the regulation change in the middle of the season, but it remains to be seen if all teams will actually agree. As said, Ferrari was not unhappy with the change, and neither are Toro Rosso and Sauber Motorsport, the two other teams running with Ferrari engines.
Until then however, and of course during tomorrow's British GP, teams will be limited to 10% throttle flow when the driver is not pushing the throttle.
Surely to be continued...