Chevrolet has filed an official appeal against IndyCar's decision last month to allow an upgrade to the single turbocharger unit used in Honda's engines.
IndyCar originally allowed the upgrade on April 18 prior to the Long Beach event but a protest from Chevrolet at the time saw Honda have to reverse the upgrade until the official protest hearing was held on April 28. The three-man panel denied the protest and allowed Honda to make the change ahead of the Sao Paulo Indy 300 in Brazil last weekend, but under IndyCar rules Chevrolet had two business days to appeal the ruling.
The disputed upgrade introduces a 0.74 A/R compressor cover that increases the power of the turbocharger and hence the engine as whole. It seeks to put the Honda's engine back on an even footing with Chevrolet's, which has been dominant so far in the 2012 IZOD IndyCar Series season.
The appeal will be heard next Wednesday, May 9, by a single individual. IndyCar's president of operations and strategy Brian Barnhart has selected retired Indiana Supreme Court Justice Theodore R. Boehm for the role.
Justice Boehm's decision will be final, and neither IndyCar nor either engine manufacturer will be able to further appeal any decision made. Honda representatives will participate in the hearing, and the proceedings will be closed to the public and media
The delay in announcing Chevrolet's formal appeal - which under the rules of the series would have had to have been filed by the end of business on Monday - is thought to be because of discussions to find a suitable person to hear the appeal that would be acceptable to all parties. Under IndyCar rules, Chevrolet will have to pay an additional $20,000 to the series to have the matter referred to a formal appeal.
It was not immediately clear whether a victory for Chevrolet in the appeal would result in repercussions over the use by Honda of the 0.74 A/R compressor cover at Sao Paulo, with IndyCar's permission.
There is no formal deadline for the issuing of the appeal decision by Justice Boehm, although typically the decision is announced on the same day as the hearing or as soon as possible thereafter in order to prevent lingering uncertainty.
With track activity for the 96th Indianapolis 500 scheduled to start just three days after the appeal, IndyCar will be keen to have the matter resolved one way or another before the cars roll out onto the Indianapolis Motor Speedway for the first time.
Relevant parts of the IndyCar rule book read: