The Porsche 911 GT3 R has received a notable power increase ahead of next weekend’s Mobil 1 Twelve Hours of Sebring.
Issued Thursday by the IMSA technical committee, the latest Balance of Performance table for the GTD Pro and GTD classes sees changes to nine of the ten GT3 or GT3-based models in the the field.
It includes a 5 mm larger air restrictor for the Porsche, which will now run with a 38 mm diameter, marking the biggest opening yet for the Type-992 model after recent tests in various different power configurations.
Several Porsches taking part in last month’s IMSA-sanctioned test at Sebring International Raceway ran with a 34 mm restrictor, which had marked a 1 mm increase over its Rolex 24 at Daytona specification.
Sportscar365 understands Porsche teams evaluated additional sizes in private testing the following week.
Concessions have also been made to fellow new-for-2023 cars from Ferrari and Lamborghini, with the Ferrari 296 getting an increase in turbo pressures albeit with a 15 kg increase in minimum weight.
The Lamborghini Huracan GT3 EVO2, meanwhile, will remain at an unchanged 1320 kg minimum weight but will have a 2 mm larger air restrictor, thus resulting in a slight power increase.
Other changes since Daytona, which utilized a standalone BoP, include 15 kg weight breaks for the Acura NSX GT3 Evo22, Aston Martin Vantage GT3, BMW M4 GT3, Corvette C8.R GTD, and Lexus RC F GT3.
The Mercedes-AMG GT3 Evo, meanwhile, has been given an extra 15 kg of weight while the Acura has undergone an increase in turbo boost pressures compared to the Aston, which will have slightly less power heading into next weekend’s second round of the WeatherTech SportsCar Championship season.