IMSA fiddles with equivalency rules again
The penultimate round of the TUDOR United SportsCar Championship season sees a number of changes in the Prototype class.
The HPD ARX-03b gets a 1.2 mm larger air restrictor but at a 40 kg minimum weight increase, while the debuting Ligier JS P2 HPD will be in the same configuration (32.5Ã-2 mm and 940 kg).
No power adjustments have been made to DP-based machinery, although the Chevrolet-engined DPs face a 6-liter reduction in fuel capacity, with the Ford EcoBoost-powered entries running 3 liters less than the most recent round at Road America.
The two HPD-powered P2 variants, meanwhile, gain 1 liter of fuel capacity.
Much-anticipated adjustments have also been made in the GT Le Mans class, including a performance break for the Corvette C7.R.
The Pratt & Miller-built car has been given a 15 kg minimum weight reduction in addition to a 0.3 mm larger air restrictor, while the BMW Z4 GTE has been handed a 0.4 mm larger air restrictor but with a 25 kg minimum weight increase.
The Ferrari F458 Italia, which claimed back-to-back class victories, will run with a 0.3 mm smaller air restrictor beginning at COTA.
GT Daytona, meanwhile, sees weight adjustments for the Porsche 911 GT America (-10 kg), Ferrari 458 Italia GT3 (+10 kg), BMW Z4 GT3 (+25 kg) and Dodge Viper GT3-R (+25 kg) while the Audi R8 LMS gets a 2 mm larger air restrictor.
The Ferrari also receives an adjustment in the maximum RPM, while the Porsche is now permitted to run a significantly different aero package featuring a 50 mm front splitter, 25 mm wheel arch extension and the addition of a single dive plane. It has also been given a 1.0 mm larger refueling restrictor.
The BoP changes in GTLM and GTD are confirmed for the remainder of the season, with the rules prohibiting any further changes to the production-based ranks. sportscar365