NASCAR shrinks plate openings

NASCAR shrinks plate openings

Before Sprint Cup cars hit the track Wednesday for practice for Thursday's Duels, NASCAR announced yet another competition change designed to slow the racing pace.
The sanctioning body reduced the diameter of the openings in restrictor plates provided to competitors by 1/64 inch, narrowing the openings from 58/64ths of an inch to 57/64ths, thereby depriving the cars of roughly 10 horsepower.
Coupled with a reduction in water temperatures engines can tolerate—thanks to the mandated 33 pounds-per-square-inch for pressure relief valves—and a reduction in the grille openings in the noses of the cars, the Cups cars won't be able to hook up in prolonged two-car drafts, as they did in Saturday's Budweiser Shootout.
In Wednesday's two Cup practice sessions, speeds dropped significantly from the 206.068 mph posted by Michael Waltrip on Lap 10 of the Shootout, the fastest lap of the event. No driver reached 201 mph on Wednesday, and indication that NASCAR's changes were having the desired effect.