BY REID CREAGER
Call Cara Adams a gearhead, and she’ll happily agree. Whether she’s working thousands of hours with compounders and chemists to research and prepare a tire for a race or walking eight miles in the pits during the Indianapolis 500 while getting feedback from engineers and technicians, she loves every day of it.
Her 2002 Bachelor of Science degree in mechanical engineering, with a concentration in vehicle dynamics at the University of Akron, eventually led to her becoming senior project engineer for race tire development at Bridgestone Americas Tire Operations. She joined the company in 2003; today, her primary design responsibility is the IndyCar superspeedway tires for Firestone.
When she started in IndyCar, she was the only female technician traveling with the series. She and Dale Harrigle, a 20-year motorsports veteran and chief engineer of Bridgestone Americas Motorsports, work 15 or 16 races a year.
Their contributions continue a tradition of consumer and racing tire innovation dating to Firestone’s founding in 1900, when the company supplied pneumatic tires for wagons and buggies. Today, Bridgestone Corp., which bought Firestone in 1988 and is the world’s largest tire and rubber company, is the parent firm; Firestone is the brand that’s used for competing in the Verizon IndyCar® Series.
We talked with Cara and Dale about racing tire innovation, as well as her role in a male-dominated sport.
Reid Creager: Did you always dream of doing this?
Cara Adams: I never imagined I would be working in racing back when I was in high school. When I was very young, my mom taught neighborhood science camps. So I developed a passion for how things work, how things are put together. Growing up, I would take things apart and put them back together. I got in trouble for that, unfortunately!
When I went into mechanical engineering at the University of Akron, I went down to the machine design shop where they put together the Formula SAE (Society of Automotive Engineers) car. It was a competition where you design and build your own race car and I started working with that group. … I kind of picked up the bug for racing then.
RC: What goes into the design of a world-class racing tire?
CA: There are a lot of things that go into a racing tire that would go into a passenger tire. Some of these things are not as important in a race tire, like snow and ice performance, but we have to design a tire that is durable, lightweight, and can maintain the speeds and loads that we see at tracks like Indianapolis and some other race tracks. At some race tracks you can see over 3,000 lbs. on the right front tire, so that’s quite a bit of load.
We put in a lot of work as a team even before we get to the race track into the designing of a tire with the lightest weight and heat-efficient materials that we can. It’s not just one person who designs a tire. We have a whole team of engineers. Racing is actually part of our advanced tire engineering group, which is really good for us so we have access a lot of smart engineers and people who work with computer simulations and modeling, things like that.
RC: Which specific materials link with consumer tire innovation?
Dale Harrigle: One key is the fundamental polymers and the rubber formulations in the race tire. A lot of those fundamental polymers that we use to try to deal with the heat generated by the racing tire or racing application translate to the consumer side, like the tractor-trailer running through the Arizona desert on a 100-degree day. Also, you need to concern yourself with how much heat the tires are generating and how to reject that heat.
Another key way that the two correlate is, we do a lot of modeling and simulation work with our race tires now, as Cara alluded to, with the team that’s part of our advanced tire engineering group here in Akron as well as within race tire development ourselves. We’ve actually pushed the people who develop those tools to improve those tools, be it wet performance or a certain type of construction or how much load we can model, how quickly and how much speed the model can return valid results for. When we increase those models’ capabilities, those capabilities also translate to other tire types and eventually to consumer tires.
RC: How many patents does Bridgestone/Firestone hold for racing tires or innovations?
CA: In racing, you have the patents versus trade secrets. We’re very much on the side of competition, so everything is more toward the trade secrets side. So we have a couple patent-related things that are visible within the tire. We talked about the transfer from racing tires to passenger tires; we also have a pattern that we borrowed from passenger tires moving to racing, like visual wear indicators. Something like that is patentable, and we have patents on things like that. But most of our stuff is more toward the trade secret side.
RC: If you can, take readers inside a day in the pits.
CA: You have a very long pit lane, and halfway in the middle of pit lane you have the area where we hang out. We’re in communication with our engineers. We have engineers and performance tire technicians at each one of the pit boxes. They’re communicating to us what the tires look like when they come off the car, what the pressure is, what the temperatures are. Dale and I will walk back and forth looking at the tires after a pit stop: how they’re wearing, what the performance of the tires is.
RC: And what kinds of feedback do engineers want back from you?
CA: If they happen to have a tire that might look like it has too much camber (wheel angle), maybe that’s something that we would pass along to them. Or, if they have something that we look and see from their tire that they might be able to adjust their suspension a little bit, we can pass that information along. … I never want to give an unfair advantage to just one team. We want to make sure the information we get helps everyone.
DH: In general, the way we try to operate is to make sure all of our work is pretty much prep work. We’re at the track to monitor and make sure we get accurate feedback so as to make improvements for the following year. Realistically, when we’re at the track, we aim for that to be the easy part of our job.
RC: Any other kinds of feedback you’re involved with?
CA: One of the things I’m able to do in my role is provide something called force and moment data (information on vehicle handling situations). We take our tires to a large machine at a facility called Calspan in Buffalo. We subject the tires to grueling loads of speeds like the tire would see on the race track and we get out a mathematical model. So we have gotten a lot of feedback from race teams as to whether that’s helped them set up their car in a way that they have been successful at the race track.
RC: How do different racing tracks require different tire designs?
DH: The Verizon IndyCar Series is the most diverse series in motorsports. We run on street courses, road courses, short ovals, medium ovals and all the way up to a 2 ½-mile track like Indianapolis. So for the 16-race season in 2016, we’ll actually make 59 different specifications of tires. The reason there’s so many specs is that on the road street courses we run in the rain, and we also use an alternate tire that has more grip but wears out quicker to give an element of strategy to the races and allows the teams to choose what tire they want to use.
Every time the car is on the track, every tire on the car is unique. Even though they may look the same, they have different constructions and different compounds based on the loads each tire sees as it navigates the track.
RC: Cara, what are the most important things you’ve learned from Dale?
CA: When I started in the group, I was the road and street course engineer, and Dale was the oval course engineer. I learned a lot about the engineering of the tires, but even more important have learned how to work with a team to help us develop the best product possible.
RC: A question you must get a lot: Have you ever driven one of these cars?
CA: One of the things I got to do a few years ago was go to Bridgestone Racing Academy. These are open-wheeled cars. You have this car with all of this power. It’s just amazing to me as a tire engineer to see how much grip these tires are able to have when you’re pushing the limits. It was a lot of fun.
RC: Tell us about the $100 million technical center that Bridgestone Americas opened in Akron in 2012.
CA: It’s really helped us have a culture shift toward innovation. We have an open atrium where you can’t help but run into other engineers. It really makes for an open environment to share ideas and talk about innovation and ideas where we’ll be able to work together as a team.