The Science of …Tony Stewart vs. Goodyear

We’ve established in Part I and Part II of this series that there are many factors that go into tire performance, some of which Goodyear has control over and others of which they don’t.

Goodyear has to determine the combination of tire compound and construction that will make for the best and safest racing. They make this decision using multiple data sources, including data and driver feedback from tire tests (some run with selected teams and others open to all teams), Goodyear’s own internal research & development, and feedback from drivers after races.

There is no debating that sometimes Goodyear gets it wrong. I cover the Lowe’s Motor Speedway issues in 2005 in my book. Briefly, the track had been resurfaced twice in the same year, and there were a lot of tire problems in both races. The track surface had become much rougher after grinding and the tires gave the drivers too much grip. The result was more heat than the tires could dissipate, which meant blown tires and Tony Stewart asking his crew chief to check and see whether Tony’s life insurance was paid up. In Goodyear’s defense, they pointed to overly aggressive coil binding setups (covered in Part II) that were putting too much force on the tires and teams trying to skirt minimum pressure requirements.

Compare Las Vegas 2007 and 2008. Las Vegas was totally reconfigured in 2007. The initial tire tests included too many car-wall interactions, so Goodyear opted to bring a much harder tire to the 2007 race than the teams had tested. None of the crew chiefs or drivers was very happy about that, in part because they couldn’t use the data they took at the test because it wasn’t the same tire, and in part because the tire was really hard. Goodyear erred on the side of a harder tire because a harder tire, although it has less grip, is much less likely to blow out.

I was at Las Vegas testing this year (2008) and the drivers had uniform praise for the tires. Dale Earnhardt, Jr. said that Goodyear could take a rest trying to make the tire better suited for the track and car.

“We’re just hard on Goodyear because we expect them to be perfect,” he said. “Maybe that’s more than we should ask for … so they take a bad rap a lot. It’s real easy to blame the tires when you don’t have a good day.”

After this year’s Las Vegas race (only a few weeks later), some drivers complained about the tires–the same tires that were pretty much uniformly lauded during testing. Why the difference? My suspicion is that the crew chiefs saw that the tires were performing fine with the setups used in Vegas testing, so they tried more aggressive tire setups for the race. That’s the crew chief’s job: pushing the limits of the car to make it go as fast as possible.

Here’s the sequence of events that led to the Atlanta tire choice: Jaime McMurray and Robby Gordon tested tires at Atlanta Motor Speedway over two days in August 2007. Goodyear analyzed the data from this test and decided on tires to use for an open test (meaning all teams welcome) at AMS in October 2007.

The open tire test raised some concerns. http://blogs.courant.com/autoracing/2008/03/goodyear-a-tire.html”>According to Mike Helton (as reported by Shawn Courchesne), the tire didn’t wear fast enough and had some other (unspecified) wear problems. Goodyear wants the tires to wear down in about one fuel run because the driver gets everything possible out of the tires, but has an opportunity to get new tires because they have to pit for fuel.

These concerns led to another tire test in December with Bobby Labonte using a harder right-side tire (for better wear) and a softer left-side tire (for better grip). Those are the tires used in the March 2008 race that caused all this controversy.

The Atlanta tires were some really hard tires. Lap times were about two seconds slower, which is a huge difference in racing. The drivers complained that they couldn’t race side-by-side and that they had to slow down to avoid crashing. Drivers really dislike having to spend an entire race babying their tires. They’d rather be thinking about what other lines they might run, not ‘how the heck am I going to pass this lap car without crashing myself?” With the possible exception of Michael Waltrip, you would be hard pressed to find a driver that had positive things to say about the tires at Atlanta.

Tony Stewart was the most vocal of the drivers. Among other things, Tony said,

“It’s not that we’re just trying to beat ’em up. We want I don’t know how else you plead with them or get their attention enough to bring something that’s better than what it is. I mean, this isn’t the first time that they’ve been to Atlanta Motor Speedway.”

The problem with the last part of his statement is that it actually IS the first time they’ve run a whole race at AMS with the new car. There are significant differences in setups between the old and new cars. The teams learned an awful lot over the off-season, so there’s no guaranteeing that the setups they used in Atlanta for the race were similar to those they had used during the October tests. Just as the teams’ notes from the last umpteen years became useless when the new car was introduced, all the data Goodyear had gathered and cataloged over the years doesn’t apply directly to the new car.

Junior suggested that the setups might be at least part of the problem. Remember that the setups determine how much force the tire feels and the distribution of that force across the tire

“I think the COT is part of it. They’re putting a lot of load on the right front tire with the bump stop. Puts a lot of load on the tires. So Goodyear thinks the tire is going to wear out worse, they’re going to have more right front tire failures. Every time they have a tire failure, they think of it as their product is getting lambasted on national television, that it’s bad news for them when the consumer sees it.
But everybody knows that watches the race, you know, there’s a reason for a tire blowing. It’s not ’cause it’s a bad tire. We’ve never had a tire blow because it was defective. I mean, you know, they wear out and you wear them down to the air. But you just need to slow down if you’re wearing tires out that bad.”

Junior makes a couple very important points here. If you read the entire interview, it’s clear that he wasn’t any happier with the tires than Tony; however, he points out that blown tires happen for a reason and that reason isn’t because the tires were defective. My suspicion that the setups were a significant contributor to the drive dissatisfaction was reinforced upon finding out that the exact same tire codes were used for the Nationwide race and the Cup race. There weren’t negative comments about the tires from Nationwide drivers (some of whom also drove the Cup race). This suggests that there is a fundamental difference between how the Nationwide setups exert force on the tires and how the Cup setups exert force on the tires. Goodyear clearly doesn’t have the new car figured out yet, but Atlanta was only the second intermediate-track race with the new car.

Many of Tony Stewarts’s complaints have translated directly into problems being fixed. The adaptation of a NASA catalyst to decrease the amount of carbon monoxide drivers breathe during races is directly attributable to Tony; however, Tony seems to think that no one listens unless he says something outrageous. In my opinion, he crossed the line needlessly when he suggested that Goodyear either didn’t have enough people, or that the people working for Goodyear weren’t capable of doing the job. You don’t give people a way out when you back them into a corner.

Compare Junior’s comments with Tony’s in the transcript posted on Jade Gurss’ blog. Junior makes some very good points, but you’ll notice that his aren’t the points quoted most widely in the press.

Goodyear didn’t do themselves any favors with the statement from Justin Fantozzi, marketing manager for Goodyear Racing.

“I’m completely satisfied (with our Atlanta tire). We’ve gone through the development process. Very happy with the product we’ve brought here from the wear standpoint.”

Fantozzi also said:

“We are tremendously proud of the wear rates we saw here.”

You can’t argue with the fact that they brought a tire that didn’t wear out. Junior said he could still see the mold imprints after running 30 laps. The tire must have been darn hard for that to happen. But Fantozzi saying that he was “completely satisfied” is a little hard to swallow.

Did Goodyear bring the wrong tire to the Atlanta race? Yep. Did Goodyear mean to bring a ‘bad’ tire to the Atlanta race? Did they do it because they are incompetent? Did they do it because they have an exclusive contract and there’s no competition? Did they do it just to get Tony Stewart riled? Not at all. As Mike Helton tried to explain on Tony’s radio show, Goodyear made the best decision they could with the data they had. They err on the side of safety, which is the side of harder rather than softer tires.

Specifying the ‘right’ tire for a track is part art and part science. Neither art nor science are foolproof. One of the biggest problems with the way we teach science is that we make people think that science experiments always work. In reality (and I’m an experimental research physicist, so I have firsthand experience with this), science experiments fail much more often than they succeed. You try things, you take data, you try to understand the data, you realize you took the wrong data or that the data isn’t valid, and you try something different. You keep doing that until you get something meaningful. In the lab, we can repeat experiments as many times as it takes until we believe the conclusions and we’re ready to submit them to scientific community for evaluation. Goodyear doesn’t have that leisure. They have a certain amount of data and time, and then they have to make a decision.

One of the things that became clear to me from reading all of the driver comments is that Goodyear doesn’t communicate very well with the drivers about how they use driver feedback during tests. (I think crew chiefs have the same problem explaining to drivers how they use their feedback during testing as well.) Dale Earnhardt, Jr. expressed some frustration:

“I’d just like to know how that process goes. I went to Texas and tire tested, but they didn’t ask me much, what I thought. So I just sit there and, you know, they got these other guys doing the testing. But the times that I’ve done it, I didn’t feel like my input was observed or looked over too well.”

When Tony made statements last year about NASCAR calling “fake debris cautions”, NASCAR gave him a private tour of the control tower so he would understand how they make those decisions. If I were in charge of Goodyear, I would extend a similar offer. Give Tony–and any other drivers who are interested–the opportunity to go through the entire process that Goodyear uses to pick tires for each track. And invite me, because I’d love to see whether the drivers come away from such a tour with a new appreciation for how hard a task Goodyear has with the introduction of the new car.

Goodyear did finally acknowledge that they wouldn’t be bringing this tire back to Atlanta, nor to Texas Motor Speedway, its sister track.

“Even though both Goodyear and NASCAR were satisfied with the tire’s performance in Atlanta, if the drivers are not happy, then Goodyear’s not happy. Now that we know how this tire combination performed, we’ll go back and retest for the fall race. We have the same goal as the drivers and NASCAR: to put the safest, best performing tires on these cars.
There will be many instances this year when the new car is on a particular track for the first time, as was the case in Atlanta. That makes it tougher than usual to get a read on how the tires will perform. But if there is ever any doubt about the recommendation, we will always err on the conservative side.”

Translated, that means: “Look folks, we didn’t have tires blowing left and right and drivers getting hurt, and that’s our first responsibility. But we know this wasn’t the right tire, and we’re going back to the drawing board before we come back to Atlanta”.

I hope this series has helped point out the complexity of this issue. After studying it, I’m actually impressed at how much of the time Goodyear gets it right. Nevertheless, drivers (and race fans) don’t want to wait until we visit each track twice before getting decent tires. Goodyear knows that and I bet there are a lot of lights on late into the night in Akron. I also bet they’re happy we’re going to Bristol this week, a track they’ve had two races at with the new car already!

A few questions that were asked multiple times this week:

Q: Who gets to tire test?

A: Goodyear invites teams to test tires. I would think they would want one driver from each manufacturer, but they often don’t invite four teams. Toyota was not happy about being left out of the Darlington tire test this week. One might suggest that drivers should be chosen by drawing lots, or rotating through all the drivers; however, listen carefully to the feedback drivers give their crew chiefs on the radio. If you’re a Goodyear engineer trying to gather information, do you want the driver whose feedback is limited to “this car is the worst it’s been all day” or the one who says things like, “The right rear is losing grip coming out of turn 4 and I can’t get back on the throttle until late”?

Q: C’mon – no one pays attention to drivers unless they make a big stink about things. If Tony doesn’t rant and rave, Goodyear and NASCAR won’t listen.

A: I think it is true that the press pays attention to the most controversial statements, but if you ask drivers who NASCAR listens to, it’s people like Jeff Burton, who can be counted upon to make rational, well-thought-out statements. Read the full interview with Tony and Junior. Junior’s comments were a lot more illuminating. He acknowledged that Goodyear has a challenge, but he also pleaded with Goodyear to please make sure that the same thing doesn’t happen at Darlington. Junior didn’t make the issue personal, which makes it a lot easier for Goodyear to admit that this wasn’t the right tire. Junior’s comments showed a great deal of insight and maturity. But Tony’s comments got most of the press. Thanks to Jade Gurss for posting the entire transcript on his blog so that we can read the unedited transcript.

Q: Why doesn’t NASCAR open up and let more than one company supply tires?

A: This is where the people who have been around awhile get to say, “those who don’t remember history are doomed to repeat it”. Full Throttle has a nice tidbit about the tire wars between Hoosier and Goodyear. The blog entry is a couple years old, but it remains relevant now. Dave Moody has an excellent blog entry on the tire wars as well. Among other things, he says:

“I was around for the tire war between Goodyear and Hoosier, and trust me when I tell you that there were no winners. The pendulum swung FAR too far in the direction of speed over safety, and drivers were hurt as a result. I’m not advocating bringing a second manufacturer into the sport. I am, however, urging Goodyear to put their vast resources to work on finding a safe – but still competitive – tire for this new NASCAR racecar; something that will keep our drivers safe, while also allowing them to put on a competitive race.

That should not be too much to ask.”

Ditto, Dave!