iNSIDE SCOOP: Pound Wise, Pressure Foolish

With the Auto Club 400 firmly in the rear view mirror, the big question this week at Texas is: will race teams be pound wise, or pressure foolish?

Pound wise refers to running more air pressure in the Goodyear Racing Eagles they bolt onto the car. As happened at Auto Club, the lower the air pressure the worse the tire problems ended up being. Lower pressures are good for going fast, but they’re bad overall when the biscuit blows up, know what I mean?

Taking into account that the surface at Texas Motor Speedway is wearing out, becoming more abrasive and doing the Ron Popeil-Ronco cheese grater thing on Goodyear’s product, the teams have their destiny firmly in their own control.

Goodyear provided each team with a chart of recommended pressures for the tires this weekend. That’s a cool piece of paper to have in hand when you’re deciding how much speed you want (as much as I can get) and how long you want the tire to live (until I hit the checkered flag). 

To wit, if you’re consistently putting 11 pounds in when the sheet calls for 15, you are racing on a rubber time bomb. It. Will. Fail. It’s just a matter of when and where. If you’re on the edge in the middle of Turn 2 at Texas, that is a badness thing.

The problem is not new. Back when Tire War II was in full song, teams would play with the pressures to get the most speed out of the Goodyear or Hoosier tire on the car. Once they went to radial tires, the problem was exacerbated because of the steel belts.

How, you ask? At low pressures, the loads on the tires flex the sidewalls. The sidewalls, for the terminally tire-tech challenged, are the part of the tire that isn’t on the track. It’s where the letters are. The sidewalls flex and distort the tire on the wheel, mounted at the bead. That in turn causes the carcass (the part of the tire that is made of nylon and rubber) to slide around on its axis, side-to-side rather than front to back.

That sliding means that the steel belts, which are laid in the center of the tire on top of the carcass and between layers of rubber, are wearing the tire from the inside out. I’ll repeat: it’s wearing on the inside as well as the outside.

Pretty soon, you run out of stuff to wear out, and the tire does what tires do when the air (nitrogen, in this case) has nothing to stop it from mixing with the ambient air…minus the fire and sparks and cement dust and all that stuff that occurs when you bounce off the wall after it happens.

When you put the recommended air in, that process is mitigated. Goodyear engineers are not dummies. They know tires, they know loads, they know the limits of the product they design. When they tell you to put X amount of nitrogen in to keep it from going boom and venting with the outside air, you should probably give that advice a listen, yes?

But, racers are contrary souls, especially when someone tells them to do it in a way they think will make them tenths of a second slower. If somebody else is doing it, and it works, it’s monkey-see, monkey-do. 

With all the things the teams are doing set-up-wise, cranking in camber and jacking with the pickup points in the suspension, especially on the left side, it’s just more nitro on the already blazing fire.

This week, when the monkeys get to seeing and doing, NASCAR says, “be careful what you wish for, because you just might get it.”

NASCAR VP of Competition Robin Pemberton was the monkey wrangler this week, and he laid down the law.

"We want to be open enough to give the teams opportunity to adjust and have different setups out there and be more aggressive or less aggressive whenever they sit fit," Pemberton said Thursday. "We want the teams to be able to push the limit, and that's what we expect out of them. If a guy has a tire issue that is self-inflicted and gets out of the car and blames Goodyear Tire and Rubber Co., that's a bad deal. That basically is what some of them tried to do at California."

In short, Pemberton said that the teams had better learn to walk the fine line between success and failure without stepping on the banana peels.