By AMANDA VINCENT
NASCAR distributed its 2018 technical rules package for the NASCAR Xfinity Series to the teams in that series on Wednesday.
The flange-fit composite body that was introduced in September at Richmond (Va.) Raceway and also will be an option for teams in the series for the Nov. 11 race at Phoenix International Raceway will be optional for all races in 2018, except for the three restrictor-plate races (two at Daytona International Speedway and one at Talladega Superspeedway).
The package used in the 2017 race at Indianapolis Motor Speedway, will be used at Pocono Raceway in Long Pond, Pa., and Michigan International Speedway in Brooklyn in 2018. That package includes aero ducts, a 64.75-inch by six-inch spoiler, and a seven-eighths-inch restrictor plate.
Changes for races at other tracks in 2018 include a common flat splitter, a common radiator that is also used in the Monster Energy NASCAR Cup Series and a reduction in brake cooling hoses and fans. NASCAR also will implement dub-frame rules aimed at preventing aerodynamic development by the race teams.
Spoiler dimensions, though, will not change, remaining at 3.5 inches tall by 60.5 inches wide.
The mandated splitter height will be four inches at all tracks.
NASCAR also will implement a single-transmission rule for all race weekends, except for road course races at Road America in Elkhart Lake, Wis; Mid-Ohio Sports Car Course in Lexington, Watkins Glen (N.Y.) International and the “roval” at Charlotte Motor Speedway.
Safety-related rule changes include a change in how incident data recorders will be powered. They will have to be powered by the cars next season, as opposed to separate batteries this season. The mandate of enhanced vehicle chassis has been changed to 2019, but new chassis will have to be certified, beginning Nov. 20, 2017.
Follow Auto Racing Daily on Twitter @AutoRacingDaily or like Auto Racing Daily on Facebook (facebook.com/autorcngdaily). Amanda’s also on Twitter @NASCARexaminer and has a fan/like page on Facebook (facebook.com/nascarexaminer).