The 2.54-mile circuit at Road Atlanta may appear unchanged to the thousands of fans at this weekend’s big 20th Petit Le Mans race, but Michelin sees a notable difference.
“Each track has its own characteristics and the track surface and grip level at Road Atlanta have certainly changed since last year,” said Ken Payne, technical director of motorsport, Michelin North America, “While not a complete repaving, the track surface has improved by grinding down some of the bigger bumps that have developed through the years and the installation of new patches and sealer on many of the key corners.”
“On a macro level the repaved areas are very smooth, but on a micro level there are lots of microscopic edges that provide extra grip,” said Payne, “Testing and simulations indicate that the track is now 1.0 to 1.5 seconds per lap quicker than last year.”
The fastest GTLM race lap in 2016 was 1 minute 18.7 seconds. An improvement of 1.5 seconds would represent nearly a two percent change, which is quite significant in GTLM terms.
In addition to possible shifts in tire compound choices and strategies, that new grip level can change aerodynamic downforce levels and suspension settings.
Michelin is working with its powerful factory linked technical partner teams from BMW, Corvette, Ferrari, Ford and Porsche to analyze the potential impacts of the changes in the track surface.
“We've advised our teams to be careful with camber and tire pressures especially with cold tires at the start of each stint,” said Payne, “It is very easy to damage a tire early in the stint before it has built proper pressures and temperatures and damage may not appear until later in the stint.”
“There is an outside chance of rain on Saturday and that would put everyone into an unknown in terms of grip levels in those repaved or sealed sections,” said Payne.
While Corvette Racing’s Jan Magnussen and Antonio Garcia are poised to claim the WeatherTech GTLM Drivers Championship and with it the Team Championship for the No. 3 Corvette Racing team, the GTLM Manufacturer’s Championship is still wide open.
Chevrolet (Corvette) leads Ford by just four points with BMW just another three points adrift. Corvette Racing has four WeatherTech Championship wins in 2017 while Ford has two wins. BMW has three wins and Porsche has one win, while Ferrari, the 2016 GTLM class winner here at Petit Le Mans, has four podiums and a pole position in just six starts.