Renault's technical director James Allison says all Formula 1 teams will be forced to change their operation following the news that FIA is to clamp down on engine mapping use from the European Grand Prix.
F1 technical delegate Charlie Whiting wrote to all teams to inform them they will no longer be allowed to change engine maps between qualifying and the race from this weekend's grand prix at Valencia. The move is aimed at stopping teams from running an extreme engine map for qualifying. That follows on from the announcement that an effective ban on off-throttle use of blown diffusers will be introduced from next month's British Grand Prix.
Although there are suggestions that the changes are aimed particularly at slowing Red Bull Racing down, Allison said on Tuesday that it will affect all teams.
"The FIA's note will cause all teams, whether or not they use a blown floor, to change their operation," said Allison. "The headline changes for the Silverstone GP are as follows: when the driver lifts his foot fully off the throttle pedal, then the ECU maps must be set up so that the engine [for all intents and purposes] closes the throttle – previously it was possible to configure the engine maps to leave the throttle open and reduce the engine power by other means.
"Furthermore, when the driver lifts fully off the throttle, the ECU maps must be configured to cut off the fuel supply to the engine – this is intended to prevent so-called 'hot blowing' where the energy of the exhaust gas is increased by combustion."
Allison, whose team pioneered the radical forward-exit exhausts this year, conceded it was difficult to know how the changes will affect the performance of its car.
"It is not easy to judge the effect of this change on our competitiveness. The loss for each blown floor car will come from two separate effects – how much downforce will you lose and, in addition, how much will the loss of this downforce upset the balance of the car?
"All blown floor cars will lose downforce under braking as a result of these new restrictions. Some teams will lose more and some teams less; it is hard to know exactly what relative loss LRGP will suffer. However, it is possible that we will suffer less on the balance shift side of the equation because our forward exit exhausts produce their effect quite near the middle of the car. This means that as the exhaust blow waxes and wanes, it does not really disturb the aero balance of the car too much.
"With a rearward blower, the downforce from the exhaust is all generated at the rear axle. As the new rules reduce the blowing effect on corner entry much more than corner exit, it is possible that the rearward blowers will tend to suffer more nervousness under braking and more understeer on exit as a result of the new restrictions. We will find out in Silverstone."
He also made it clear his team is against changing the rules during the season.
"We would have preferred the status quo to remain for the rest of the season," Allison added.