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McLaren’s and Mercedes’ Rear Diffusers Ruled Illegal by FIA

The Mercedes W01 rear diffuser - now illegal

In yet another example of the FIA’s clumsiness in implementing and enforcing their technical regulations, they have made an ad hoc ruling that four teams are currently using illegal rear diffuser configurations.  McLaren, Mercedes and two other teams have been ordered to revise their current diffuser designs in advance of the Australian Grand Prix on March 28th.

At question is the size of the starter motor opening which is incorporated in the cars’ diffuser designs.  Air channeled through a car’s  diffuser generates downforce, and maximizing the size of the opening for the starter motor enhances this effect.

As is often the case in F1 regs, the wording is vague enough to allow multiple interpretations.  According to Article 3.12.7 in the FIA technical regulations, “A single break in the surface is permitted solely to allow the minimum required access for the device referred to in Article 5.15.”  But what are the exact dimensions required “to allow minimum required access”?  This is not specified.

To help justify the use of larger ports for starter motors, some teams have actually reverse-engineered the design, by constructing rather stout starter motors, which in turn forced them to enlarge the ports used to accommodate these devices.  But the FIA has decreed that this ploy violates the spirit of the rules.

Discussions were held with several teams at last weekend’s grand prix venue, in Bahrain, and today the FIA has issued a final decision on the matter.  The teams must now introduce new diffusers in time for the next event at Melbourne.  Along with McLaren and Mercedes, it’s believed that Renault and Force India must also make diffuser alterations.

As reported in Autosport, last weekend in Bahrain, while the matter was still being deliberated, McLaren team principal Martin Whitmarsh politely took issue with the FIA’s investigation.  “There are holes in the diffuser for the starter, the hole in ours is no bigger than the one on the championship winning car last year,” he said. “And also no bigger than it is on about four other cars.”

Forcing the teams to make a critical change to their aero packages between to fly-away races, with only a week’s margin until the next race, is both illogical and draconian.  It’s well known that little development takes place on most cars during the first leg of the F1 season, when most of the races are fly-aways.  Most teams, for logistical reasons, wait until the first European leg of the season begins before they introduce their first phase of upgrades. With only a week before Melbourne, it’s likely that the teams are already preparing the transport of equipment for the race.

Of course, once they knew the matter was under review, the better-prepared teams probably put together a plan B, just in case.  McLaren did this prior to Bahrain: they brought alternate body and dorsal fin parts to the race, just in case the FIA decided at the last minute that McLaren’s new rear wing vent was illegal.  Fortunately for McLaren, that wasn’t the case.

But in an era when, theoretically, the FIA is trying to hold down costs, it seems counterproductive to make technical rulings on the fly, forcing the teams under review to scramble to make last minute, costly revisions to their cars.

When you consider the lead time required to build a Formula 1 car, and the fact that chassis are now homologated, it would make sense for teams to get complete FIA approval at the beginning of the season.  Granted, new aero packages are introduced throughout the year, but in an age when 3-D virtual mock-ups of anything from a rear wing to a wing nut can be easily rendered, the FIA should be able to implement an ongoing approval process with a workable time line.  After all, we’re not talking about clinical trials of cutting-edge pharmaceuticals here.

And while Mercedes didn’t introduce their final diffuser package until the first race weekend, in Bahrain, if the approval process were built into everyone’s timelines, late upgrades of this sort could be accommodated.

Or course, this process could also be simplified by making the technical regulations more specific.  Such elements as tire size, wing area and wheelbase width are clearly specified in the regs, while other elements are outlined in more general terms, as indicated above.  If the gray areas were eliminated, certainly that would eliminate much of the confusion and last minute retooling.

{ 2 comments… add one }
  • Vettel Fan March 21, 2010, 10:51 am

    Wow. That is interesting. I’m curious if they will find that McLaren is the same size hole as last years car. FIA needs to actually go back to refueling in my opinion. The pit stop strategies allowed more interesting racing, but then again, we’ve only seen just one race. Hopefully we will see some changes.

  • Craig Scott March 23, 2010, 12:32 am

    No, McLaren’s design is new. They said during the winter that they were going to push the envelope on diffuser design. I guess they pushed too far.

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