Monster Energy NASCAR Cup Series, Race No. 4 – TicketGuardian 500
NASCAR Series, Race No. 4 – DC Solar 200
Combination of speedway, short track characteristics pose a challenge at Phoenix: ISM Raceway is a mini speedway, but its one-mile length and three distinct corners make it race like a short track as well. Those factors pose a challenge for crew chiefs, in that they need to create as much aerodynamic advantage as they can, while at the same time keeping temperatures inside the engine compartment cool enough that they don’t hurt the tires. Without adequate cooling, the combination of engine heat (with the front of the car being so tightly sealed off) and heavy braking can cause sustained heat over the course of a run that can damage the rubber in the bead area of the tire that seats up against the wheel. If that area weakens as a result, the tire will suffer an air loss.
“Teams really have to work hard at Phoenix to strike a balance between keeping their tires cool and sealing up the front of the car to get us much front downforce as possible,” said Greg Stucker, Goodyear’s director of racing. “While Phoenix has speedway characteristics, it sometimes requires heavy braking as well. With brakes operating at north of 1,000 degrees, that heat gets transferred directly onto the tire, which can cause what has come to be known as a ‘melted bead.’ What really happens is the rubber that encases the metal bead wires inside the tire degrades from that sustained heat, eventually causing an air loss.”
Teams in both the Monster Energy NASCAR Cup and Xfinity Series will run the same tire set-up at Phoenix this week, the same combination of left- and right-side tires that NASCAR teams have run at this track since the beginning of 2016. Phoenix is the only track at which these teams run either of these two tire codes.
As on most NASCAR ovals one mile or less in length, teams will not run liners in their tires at Phoenix.