Perry Hyder, Michelin race tire engineer with Highcroft Racing. Photo credit: Rick Dole

Perry Hyder, the Michelin race tire engineer with the defending ALMS prototype champion Highcroft Racing HPD team thinks that fans may see a two-part race here today at Mazda Raceway Laguna Seca.

Hyder expects the first half of the six-hour race on the hilly, low-grip, 2.238 mile circuit to be sunny and warm, but it is the cool and potentially windy second half that may determine the winners and has the full attention of the teams. The changing conditions and yellow flag caution periods will be keys to the race.

The six-hour race begins at 2:30 p.m. Pacific time and ends at 8:30 p.m. Official sunset is at 8:14 p.m.

Michelin technical partner Prototype teams from Highcroft, Drayson and CytoSport Porsche have the choice of a new Michelin “soft” compound developed for the upcoming 24 Hours of Le Mans or the highly successful Michelin “street soft” tires, the softest compound tires that Michelin has ever used in sports car competition.

“Once the sun starts moving over the hills, the track cools very quickly,” Hyder said. “I think everyone will be running their softest tires during the second half of the race. The question for us will be when to make the switch to the Michelin ‘street soft’ tires.”

The decision is not based upon ambient or air temperatures, but solely upon the track temperatures, and those temperatures can change dramatically. During green flag conditions teams typically pit about once each hour for fuel, but caution periods may open the opportunity for additional stops for fuel, tires, and driver changes.

“You need to keep track of the temperatures and how your car is working so that you are prepared in case of a yellow,” Hyder said. “You are typically thinking one, or even two stops ahead, trying to anticipate what the situation will be an hour or even two hours later.”

Hyder explained how drastic the changes can be in a short period of time.

“In practice on Thursday evening, the track went from 86 degrees at 4:40 p.m. all the way down to 59 degrees at 8:00 p.m.,” Hyder said. “That is a big temperature change in a fairly short span.”

Both wind and cars drag sand and gravel back onto the circuit from off-course excursions through the circuit’s Moto GP sand boxes, which narrows the racing groove throughout the race. This makes moves through traffic especially dicey, and increases the risk of pick-up on the tires.

“The challenge late in the race will be if you have an extended yellow caution period, it will be tricky to get the tires back up to temperature on the restarts,” Hyder said.