FLRacingFan
Team Owner
The different packages will be tailored to the specific tracks on the Monster Energy Series circuit, with a combination of a smaller tapered spacer to reduce engine horsepower to a target goal of 550 (from 750) and aero ducts to foster tighter racing on a majority of speedways measuring longer than 1 mile. Both features will be in place for 17 of the 36 races next season, excepting the 2019 Daytona 500, which will run with traditional restrictor-plate rules. Five other races will be run with the smaller spacer, but without ducts.
The baseline aero elements of the 2019 rules package are a taller 8-inch by 61-inch rear spoiler, a larger front splitter with a 2-inch overhang, and a wider radiator pan that measures 37 inches wide in the front tapering to 31 inches at the rear. Those base changes will be in place at every race next season with the intent of adding downforce to stabilize handling, a break from a trend of downforce reduction from 2015-18.
Beyond the baseline components are the smaller tapered spacer (.922-inch versus the current 1.17-inch) and aerodynamic ducts to be used at select oval tracks larger than 1 mile. The smaller spacer will further limit airflow through the engine and thereby horsepower to a figure around 550, down from the current 750.
Five races at larger ovals are exceptions. Both Pocono events and races at Atlanta, Darlington and Homestead will use the smaller tapered spacer, but will not use the aero ducts that transfer air to the side of the car away from the front tires. Neither the smaller spacer nor ducts will be used at short tracks and road courses.
https://www.nascar.com/news-media/2018/10/02/2019-rules-packages-announced-monster-energy-series/