IMSA has released Balance of Performance adjustments ahead of next month’s Mobil 1 Twelve Hours of Sebring, featuring changes primarily in the production-based GT Le Mans and GT Daytona categories.
The Prototype class remains unchanged from January’s season-opening Rolex 24 at Daytona, except for all cars adopting high-downforce aero packages, which for DPs includes the addition of the rear diffuser.
Additionally, the Dinan-BMW-powered Riley has received a 3 liter reduction in fuel capacity compared to what it ran at Daytona last month.
GTLM sees incremental changes in weight, air restrictor, gurney and fuel capacity for the majority of the competitors.
The Aston Martin Vantage GTE has been given a 15 kg minimum weight increase while the BMW Z4 GTE will be allowed to shed 10 kg compared to its configuration run at Daytona.
Both cars, along with the Rolex 24 class-winning Corvette C7.R will have a 15 mm increase in gurney height, while the Corvette has been given a 0.3 mm reduction in air restrictor, which will translate to a slight loss of power.
Both the Ferrari F458 Italia and Porsche 911 RSR, meanwhile, have fuel capacity adjustments, with the Porsche losing 4 liters and the Ferrari down 1 liter.
In addition to its wright increase, the Aston Martin must revert to its standard downforce package. It was the only GTE car permitted to run its Le Mans aero kit at Daytona.
There are adjustments across the board for all six manufacturers in GTD.
The biggest change comes from the Daytona class-winning Dodge Viper GT3-R, which has a 40 kg weight increase, 200 rpm reduction, 0.5 mm increase in ride height and minor adjustments to the gurney and fuel capacity.
The BMW Z4 GT3 has also gained 40 kg and sees a significant 19 mm reduction in (single) air restrictor, while the Aston Martin V12 Vantage GT3 and Audi R8 LMS both have a 20 kg weight increase.
The Ferrari 458 Italia GT3, meanwhile, gains 35 kg and has a 250 rpm reduction, with a 4 liter reduction in fuel capacity as well.
The Porsche 911 GT America is the car that’s remained relatively unchanged, aside for a 5 mm increase in gurney.
In a first for IMSA, the BoP adjustments were announced nearly a month ahead of the next race, which is scheduled for March 21 at Sebring. Per the regulations, IMSA has until seven days prior to the start of official on-track activity to announce changes.