IMSA has released an initial draft version of its Balance of Performance for the GT Le Mans and GT Daytona classes to manufacturers for the TUDOR United SportsCar Championship season-opening Rolex 24 at Daytona.

Discussions, meanwhile, are still ongoing in the finalization of the BoP, which should be solidified in the coming days.

As previously documented by Sportscar365, the production-based cars will run in Daytona-specific trim, with changes having provisionally been made to nearly all of the cars since October’s 2014 season-ending Petit Le Mans.

All of the proposed changes below remain provisional, pending final discussions:

In GTLM, nearly all of the cars are set for a boost in horsepower, while many could undergo adjustments in minimum weight and aerodynamic devices.

The BMW Z4 GTE will is currently listed to receive a 25 kg weight break, 0.3 mm larger air restrictor and 15 mm reduction in gurney size for Daytona, with the Corvette C7.R tabbed for the same adjustments, except for a 0.6 mm increase in air restrictor.

Ferrari’s F458 Italia GT could remain at its base weight of 1200 kg but gets a 0.3 mm larger air restrictor, while also being permitted to run its rear wing 50 mm lower.

The Aston Martin Vantage GTE has been given no fewer than four adjustments, with a 25 kg weight increase, 0.6 mm larger air restrictor, 15 mm reduction in gurney and permitted installation of its Le Mans “bubble” splitter and removal of dive planes.

Defending class winners Porsche, meanwhile, are the only GTLM manufacturer to face a reduction in power, with the Porsche 911 RSR set to run a 0.3 mm smaller air restrictor, but with a 5 kg weight break.

BoP adjustments, meanwhile, have been made to each model in GTD as well.

The Aston Martin Vantage V12 GT3 receives a 9 kg weight increase and 15 mm reduction in gurney, while the Audi R8 LMS will get a 5.7 mm larger air restrictor but will be mandated to run with a DP specification Crawford rear wing and 2011-spec dive planes.

BMW’s Z4 GT3 sheds 50 kgs compared to its championship-winning configuration in 2014, while the Chrysler-homologated Viper GT3-R remains at the same weight and restrictor but with a 10 mm reduced gurney and mandated use of a DP rear wing as well.

The Ferrari 458 Italia GT3, which claimed class honors at Daytona one year ago, sees a 15 kg reduction in minimum weight and 100 rpm increase in max RPM. The Prancing Horses must utilize FIA GT3-homologated bodywork for the first time. It will also race with a revised front Continental tire.

Porsche’s 911 GT America, meanwhile, will have a 15 mm reduction in gurney and will be permitted to adjust the front wheel arch wicker.

The above changes, issued by IMSA this week, will go into effect beginning at the Roar Before the Rolex 24 on Jan 9-11 and should remain unchanged for the Rolex 24.

Sandbagging penalties will apply should any team or manufacturer be found not to use the full potential of their car at the Roar, as outlined in the below line in the bulletin:

“It should be noted that the performance levels exhibited at the pre-season Roar before the 24 test will define the expected performance level for the Rolex 24 race event. Any performance which is outside of the expected level shall be penalized accordingly during or after the race event.”