By alley - Mar 14, 2017, 8:57 AM ET

IMSA makes final tweaks to Sebring BoP

IMSA has made final adjustments to the Balance of Performance tables to a select number of cars set to compete in Saturday's running of the Mobil 1 Twelve Hours of Sebring. The latest BoP changes follow analysis made by the series' technical staff after the recent WeatherTech SportsCar Championship test at the 3.7-mile road circuit.

Cadillac's DPi-V.R was the only model in the Prototype class to receive increased sanctions designed to reduce its pace, and this follows

a significant effort to slow the car

through BoP at the Sebring test. The Rolex 24 at Daytona-winning chassis became the first to receive a weight increase during the new Daytona Prototype international formula, and its two teams, Action Express Racing and Wayne Taylor Racing, will race at Sebring at a minimum of 950 kilos (+20kgs).

IMSA has also taken more power from the Cadillac, which led every Sebring test session, by reducing the airflow to its 6.2-liter V8 engine (2 x 31.0mm restrictors, -0.6mm total).

In GT Le Mans, fuel cell capacity and refueling tank flow adjustments were made starting with BMW's M6 GTLM, which will race with 105 liters to fill (+4.0L). Porsche's 911 RSR has also received an increase with its cell to 97 liters (+3L) and its refueling hose restrictor (+1 mm). Ferrari's 488 GTLM will join the Porsche with faster refueling (+2mm) and will also have a new refueling receptacle for Sebring.

GT3-based models in the GT Daytona class received the highest volume of changes from IMSA. Acura's new NSXs will race at 1300 kilos (+20kgs), more boost fed to its twin-turbo V6s from 2000-6500 rpms, and will have 107 liters of fuel on board (+1L). Audi's R8 LMS will race at 1320 kilos (+5kgs), Mercedes' AMG GT3 will race at 1340 kilos (+20kgs) while feeding more air to its 6.3-liter V8 engine (2 x 36.0mm, +1.5mm) and will carry 104 liters of fuel (+2.0L).

GTD fuel cell capacity changes close Sebring's BoP with Lexus preparing to race its RC Fs with 93 liters (-1L) and Porsche 911 GT3 R entrants receiving a bump to 91 liters (+2.0L).

Practice for the 65th annual Sebring race begins on Thursday.