Renault technical director James Allison admits it is difficult to judge what impact the ban in off-throttle blown diffusers will have on the team during the British Grand Prix this weekend.
Silverstone will mark the first event in which the device is banned after the FIA deemed the part to be illegal, with Renault believed to be one team that could suffer due to the unique exhaust fitted to its car.
However, Allison revealed that that unique exhaust could in fact work in Renault's favour although it was impossible to tell before cars hit the track this weekend for the first free practice session.
“It is not easy to judge the effect of this change on our competitiveness,” he said. “The loss for each blown floor car will come from two separate effects – how much downforce will be lost 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 aerobalance 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 at Silverstone!”
Team boss Eric Boullier agreed that it was difficult to tell what impact the changes will have but said it was down to the team's to cope with the off-throttle diffuser ban as quickly as possible.
“It's a complicated issue and difficult to state their exact impact just yet,” he said. “What's certain is that we need to anticipate the changes to the regulations in the best way we can. It will definitely affect every single team, and it's up to us and our engineers to cope better than our competitors with the changes.”