The upcoming NASCAR weekend at Phoenix Raceway carries with it yet another new rules package and a warning from the sanctioning body’s single tire supplier.
Unlike the previous two weekends, in which the Monster Energy NASCAR Cup Series utilized the 550-hp target with increased downforce and drag, the first short track race of the season will feature a return to the 750-hp range that has been in place since 2015. The engines would ordinarily turn 900 hp without the tapered spacer that is used to throttle speeds.
However, the cars will still feature the larger spoiler and splitter from Atlanta and Las Vegas, maximizing downforce while also increasing speeds and tire loads while in corners.
Goodyear says teams need to be mindful of the recommended tire pressures this weekend.
"When we tested on this package at Phoenix last fall, teams were considerably faster than we’ve seen in recent years," said Greg Stucker, Goodyear’s director of racing. "With the extra downforce versus the 2018 rules package, much of that speed comes through the corners, which generates higher loading on the tires.
"Teams will need to be mindful of our recommended air pressures as they develop their set-ups to optimize grip. Running below our minimums can cause the sidewall of the tire to flex more and over-deflect, generating more heat, higher wear and fall-off, and even damaging the tire to the point of air loss.
"Finding that balance will be key."
These tires were tested at the 1-mile track last October by Denny Hamlin, Matt Kenseth, Kyle Larson and Paul Menard.
Compared to what Cup and Xfinity teams ran at Phoenix last November, the left-side tire features a construction update that Goodyear intends to use at several tracks this season, while the right sides feature a compound change created to provide fall-off and run cooler.
The exact specs can be found below.
Set limits: Cup: three sets for practice, one set for qualifying and eight sets for race; Xfinity: six sets for the event
Tire Codes: Left-side — D-4864; Right-side — D-4866
Tire Circumference: Left-side — 2,227 mm (87.68 in.); Right-side — 2,245 mm (88.39 in.)
Minimum Recommended Inflation: Left Front — 14 psi; Left Rear — 14 psi; Right Front — 32 psi; Right Rear — 30 psi
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