After testing, IMSA altered the balance of performance in all four categories in an attempt to achieve parity within them. The BR01, DeltaWing and Ligiers received ballast increases to affect their handling. The Rileys, Ligiers and Lolas had their turbocharger boost pressures lowered to reduce performances. The Corvette Daytona Prototypes had performance changes. The eight PC vehicles had the position of their rear wings adjusted to affect its aerodynamic efficiency. BMW. Ferrari, and Ford had their turbocharger boost pressures cut to lower top speeds. Porsche's and Corvette had fuel tank size increases of . The GTD, Aston Martin, Audi, Dodge and Ferrari all had of weight deducted, as Lamborghini and BMW received ballast increases of the same amount. Porsche received a fuel capacity increase of .
