The FIA International Court of Appeal has ruled that the diffusers run by Brawn GP, Williams, and Toyota are legal. The reasons for the decision haven’t been handed down as of writing but this means that the three teams will be able to race this weekend in China.
The whole brouhaha started before the season even began when some teams questioned the legality of the three teams’ diffusers. The FIA did not attempt to make a rules clarification until March when F1 arrived in Australia for the season opener. There and at Malaysia the FIA technical delegates and race officials ruled that the diffusers in question were legal. Four teams (Ferrari, Renault, Red Bull, and BMW) decided to protest the decision to the International Court of Appeal which brought us to today’s decision.
As this whole clustermess has gone along, FIA procedures have been called into question repeatedly. Many have asked why it has taken so long to have an appeal meeting which meant that a ruling against Brawn and co. would have meant two race results would be thrown out. Also, the FIA had plenty of advance warning about the impending diffuser battle but chose to do nothing until teams reached the track. Add to this the feeling that the FIA would rule in the diffuser teams’ favour because they didn’t want to contradict their stewards or rewrite two race results. The feeling is that the FIA’s primary concern is with following procedure rather than doing what is best for racing and the fans.
Now, the seven other teams will have to develop their own double-decker diffusers to catch-up to Brawn, Toyota, and Williams. This process won’t be easy because not only will a diffuser have to be designed but the rear suspension and rear bodywork will need some modifications to improve the performance of the diffuser. In all likelihood, the Spanish Grand Prix will look like a mass car unveiling with seven teams likely rolling out mostly new cars. I say likely all seven because low budget Force India may not have the cash or other resources necessary to develop a new diffuser in 3 weeks.
Finally, there’s a question at another website that I’d like to take a crack at answering. The question is how the new diffusers would affect overtaking. The concern was that the increased downforce would make it harder for a car to follow. I could be wrong, but I believe that there won’t be any negative effect and perhaps a small benefit. For a diffuser to be at its best, the air has to be as clean as possible coming out the back. The dirty air and turbulence off the rear wing is what makes overtaking difficult. Therefore, clean air off the diffuser shouldn’t hinder passing attempts. Also, more downforce from the diffuser should mean that teams run their wings at lower angles because they need less downforce from the wings. This would mean less dirty air off the cars’ rear wings and making it easier for other cars to follow and pass. This is the same principle that Champ Car used with the DP01 car. It got more downforce from the diffuser than wings so the cars wouldn’t be as aero-sensitive when following and that worked for them.
Related: How Do Formula One Diffusers Work