IMSA News: 10 of 11 GT teams get BoP adjustments for Rolex 24

IMSA has issued comprehensive Balance of Performance adjustments to the GTD Pro and GTD classes ahead of this weekend’s Rolex 24 at Daytona.

Confirmed on Wednesday by the sanctioning body, changes have been made to ten of the 11 GT3-spec cars across multiple parameters.

In accordance with the tables below of the IMSA WeatherTech SportsCar Championship SSR, the following Balance of Performance values are set for the indicated Car Models. The column listed as current is the current specification after any adjustment is applied and thus the required specification for the Event(s). These decisions come into effect immediately and are applicable until further notice.

GTD	Vehicles		Mass		Engine						Ride Height	Rear Wing		Fuel					Notes
GTD PRO	Vehicles		Mass		Engine						Ride Height	Rear Wing		Fuel					Notes
	Manufacturer		Minimum No Fuel/Driver (kg)		Restrictor Diameter (mm)			Average Power Delta (kW)	Maximum RPM		Minimum Ground Clearance (mm)	Min Angle (deg)		Type	Lambda	Total Capacity (L)		Minimum Full Refueling Time (sec)
			adj	current	qty.	adj	current	adj	adj	current	current	adj	°		λ	adj	current

	Acura	NSX GT3		1320				+7.1		7500	50.0		+4.8	IMSA 100	0.88	+2.0	111.0	40.0	EVO II
	Aston Martin	Vantage GT3 EVO	-10	1325						7200	50.0		+4.8	IMSA 100	0.91	+1.0	109.0	40.0
	BMW	M4 GT3		1310				+9.1		7250	50.0		+2.4	IMSA 100	1.10	+3.0	101.0	40.0
	Corvette	Z06 GT3.R		1335	1		50.0			8000	50.0	+1.0	+4.3	IMSA 100	0.88	+2.0	105.0	40.0
	Ferrari	296 GT3	+10	1365				-4.0		8000	50.0	+1.0	+3.8	IMSA 100	0.90	-1.0	104.0	40.0
	Ford	Mustang GT3	+15	1330	2		35.0			8250	50.0		+6.8	IMSA 100	0.88		109.0	40.0
	Lamborghini	Huracan GT3 EVO2	+5	1355	1		50.0			8500	50.0		+3.8	IMSA 100	0.91		109.0	40.0
	Lexus	RC F GT3		1370	2		40.0			7200	50.0		+5.3	IMSA 100	0.86		107.0	40.0
	McLaren	720S GT3 EVO	-10	1330						8000	50.0		+2.8	IMSA 100	0.88	+2.0	113.0	40.0
	Mercedes	AMG GT3	-15	1375	2	+1.0	34.5	+8.5		7700	50.0	-1.0	+1.5	IMSA 100	0.90	+3.0	103.0	40.0
	Porsche	911 GT3 R (992)	+20	1325	2		36.0			9400	50.0	-1.0	+5.5	IMSA 100	0.89	+2.0	97.0	40.0

Acura NSX GT3			Aston Martin GT3 EVO		BMW M4 GT3			Ferrari 296 GT3			McLaren 720S GT3 EVO
Engine Speed	Boost Ratio		Engine Speed	Boost Ratio	Engine Speed	Boost Ratio		Engine Speed	Boost Ratio		Engine Speed	Boost Ratio
Engine Speed	Boost Ratio		Engine Speed	Boost Ratio	Engine Speed	Boost Ratio		Engine Speed	Boost Ratio		Engine Speed	Boost Ratio
[rpm]	adj	current	[rpm]	current	[rpm]	adj	current	[rpm]	adj	current	[rpm]	current
2000	0.060	1.930	2000	1.510	2000	0.054	2.112	2000	-0.020	1.883	2000	1.681
4000	0.060	1.930	4000	1.510	3000	0.054	2.112	4000	-0.020	1.883	4000	1.681
4500	0.060	1.934	4250	1.549	3500	0.054	2.112	4500	-0.020	2.183	4500	1.675
5000	0.062	1.982	4500	1.588	4000	0.056	2.169	5000	-0.020	2.424	5000	1.668
5500	0.063	2.011	4750	1.637	4500	0.058	2.237	5500	-0.020	2.408	5500	1.662
6000	0.063	2.026	5000	1.686	5000	0.060	2.328	5750	-0.020	2.414	5750	1.642
6200	0.063	2.030	5250	1.721	5250	0.061	2.389	6000	-0.020	2.420	6000	1.623
6300	0.063	2.040	5500	1.755	5500	0.063	2.469	6250	-0.020	2.423	6250	1.594
6400	0.063	2.043	5750	1.794	5750	0.066	2.560	6500	-0.020	2.425	6500	1.565
6500	0.063	2.041	6000	1.794	6000	0.066	2.579	6750	-0.020	2.402	6750	1.522
6600	0.063	2.036	6250	1.794	6250	0.067	2.600	7000	-0.020	2.379	7000	1.478
6700	0.063	2.025	6500	1.794	6500	0.064	2.518	7250	-0.020	2.344	7250	1.444
6800	0.062	2.009	6750	1.765	6750	0.062	2.425	7500	-0.020	2.310	7500	1.411
7000	0.061	1.975	7000	1.745	7000	0.058	2.281	7750	-0.020	2.245	7750	1.406
7500	0.059	1.915	7200	1.745	7250	0.056	2.173	8000	-0.020	2.180	8000	1.401
7800		1.000	7500	1.000	7500		1.000	8500		1.000	8300	1.000

The Mercedes-AMG GT3 Evo, BMW M4 GT3 and Acura NSX GT3 Evo22 are getting the largest performance breaks.

The Mercedes-AMG, which qualified near the bottom of the time charts in both GTD Pro and GTD, has received a 15 kg weight reduction and 1 mm larger air restrictor, which marks roughly an 11-horsepower increase. Additionally, the Mercs will run at 1 degree of reduced rear wing angle.

BMW’s GT3 challenger, meanwhile, will have a 12-horsepower increase through adjusted boost pressures, with the Acura getting roughly a 9.5 additional horsepower.

The Porsche 911 GT3 R, which claimed GTD Pro pole with Seb Priaulx, and the Ford Mustang GT3, which qualified near the back of the pack, have been among the hardest hit with the adjustments.

The Type-992 Porsche will have a 20 kg weight increase, and -1 degree change in minimum rear wing angle, while the Mustang GT3 gets 15 kg of added weight.

Weight additions have also been made to the Ferrari 296 GT3 (+10 kg), Lamborghini Huracan GT3 EVO2 (+5 kg), with weight breaks for the Aston Martin Vantage GT3 Evo and McLaren 720S GT3 Evo (both -10 kg).

Additionally, the rear wing angles for the Ferrari and new Chevrolet Corvette Z06 GT3.R have both been increased by 1 degree.

Fuel capacity adjustments have been made to eight of the cars, ranging from 1 to 3-liter adjustments.

The only car to not have received any form of BoP change was the Lexus RC F GT3, which scored GTD class pole honors in the hands of Parker Thompson.