IndyCar announced Tuesday that all engines will maintain a turbocharger boost level 130 kPa for Sunday's Indianapolis 500.
"After evaluating a variety of options and speaking with all engine manufacturers, we feel it is best from a both a competition and safety standpoint to maintain the current superspeedway boost level for our Lotus-powered entrants," said IndyCar vp of technology Will Phillips.
"At this point, there are too many unknown variables in allowing an engine to run a full-race distance at the increased boost level, so it's something we are going to need to explore further. At the beginning of the season we mandated there would be no changes to performance regulations prior to June 18, and we plan to maintain that time frame."
The announcement comes as a blow to the two Lotus-powered teams – Team HVM's Simona de Silvestro and Fan Force United's Jean Alesi – who were the race's two slowest qualifiers, and had hoped to be allowed to run with their higher qualifying level of boost on race day for safety reasons. Beaux Barfield, IndyCar's president of competition, indicated that de Silvestro's and Alesi's pace would be the subject of careful scrutiny.
"From a safety standpoint, we will be keeping a close eye on speeds as the race progresses to ensure that all cars are within 105 percent of the race leader's pace," said Barfield. "We want to make sure that we are managing the speeds and car placement as the drivers navigate through traffic."