Dr. Diandra: The science behind four Indy 500 wins for Helio Castroneves across 20 years

Helio Castroneves Indy science
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To someone such as me who loves the science and technical aspects of motorsports as much as the actual racing, the most impressive element of Helio Castroneves’ four Indy 500 wins over two decades is his ability to excel in a constantly changing sport.

For example, Castroneves’ first Indy 500 win came just as the competition level started to rise.

As the plot below shows, only a handful of cars finished on the lead lap as recently as the early 2000s.

Now, more than half the field routinely completes the entire race.

DNFs have fallen from around 20 cars in the 1980s to more like seven or eight in recent years. Last year’s Indy 500 featured only three DNFs.

But some metrics haven’t changed much at all in the last few decades, despite numerous changes to the race car.

For example, the second plot (again below) shows that pole speed has varied by only 12 mph in the last 22 years.

The lowest value was 222.02 mph in 2004 and the highest during that timeframe is this year’s record 234.05 mph. (Though the fast speeds this year are just as attributable to favorable weather as to the track and the car.)

The plateauing of pole speeds speaks to the three challenges IndyCar — and every other racing series — must master: safety, cost and competition level.


Safety

The single biggest thing that jumps out about how safety has changed over the course of Castroneves’ wins is that the Indianapolis Motor Speedway did not have SAFER barriers for the 2001 Indy 500.

IndyCar — and founder Tony George in particular — pioneered barrier development, starting with the PEDS (Polyethylene Energy Dissipation System) in 1998.

Plastics such as polyethylene are softer and more resilient — an obvious improvement over concrete. Unfortunately, the soft barriers grabbed cars, bringing them to a stop instead of slowing them down.

Engineer Dean Sicking, then at the University of Nebraska, set a lot of heads shaking when he suggested that hollow steel tubes and foam would be safer than plastic or concrete.

Sicking’s vision prevailed and the first version of the SAFER (Steel and Foam Energy Reduction) barrier was installed at IMS in the fall of 2001. Robby McGehee memorably tested the new construction during the lead-up to the 2002 Indy 500.

One safety feature already implemented in time for Castroneves’ first Indy 500 run was the HANS (head and neck support) device. Head and neck support devices slow down the head’s motion in a crash, reducing the likelihood of head and neck injuries.

Along with track improvements such as SAFER barriers and catchfencing, and driver equipment such as six-point restraints and stronger helmets, the race car itself became safer.

The most recent improvement is the aeroscreen introduced in 2020 to protect drivers from injuries due to rollovers and debris. That increased protection, however, introduced a new issue: heat.

“We didn’t worry about core temperature in IndyCar before (the aeroscreen),” said David Ferguson, associate professor of kinesiology at Michigan State University. “And now it’s a big problem.”

Core temperature measures how hot your organs get. They like to be about 37 degrees Celsius (98.6 degrees Fahrenheit). Your body maintains that temperature by sweating when it gets too warm, which means drivers must take extra care to avoid dehydrated.

If your core temperature rises, Ferguson said, you’ll get a headache and hav difficulty thinking clearly, followed by dizziness and possibly passing out.

“The older you get, the more influence dehydration has on you,” Ferguson said, though the effects don’t become pronounced until you’re around 50.

Castroneves turned 47 two weeks ago.

“So he’s getting close,” Ferguson said, “but we know that fitness, nutrition… all that is beneficial toward staying hydrated and healthy. I know Hélio works very hard at that.”


Cost and Competition

The remaining two constraints are linked: How do you provide the best racing without bankrupting car owners?

One approach limits the parts teams can modify, which reduces research and development costs. The universal aerokit is one example of this philosophy.

But, as noted earlier, none of the many modifications to chassis and aerodynamics have produced higher speeds.

“I would dare to say that they don’t want the speed to increase a ton more,” Jonathan Diuguid said.

Now managing director of Porsche Penske Motorsports, he was Castroneves’ race engineer from 2013-2016. Diuguid said the car has been fundamentally the same since 2012.

“What’s changed,” he said, “is the operational side.”

Today, for example, there’s less on-track testing but more sensors and more data.

“Back in 2001,” Diuguid said, “if you were logging something at 50 Hertz, you were doing pretty well. Now we log sensors at 1000 Hz.”

A sensor running at 50 Hertz records 50 measurements each second. That’s 180,000 measurements in an hour. At 1000 Hertz, that’s 3.6 million pieces of data an hour from each sensor. And there are more sensors now than there were back in 2001. But collecting data is only the first step.

“Ultimately,” Diuguid said, “you can have all the data in the world, but if somebody can’t use it to make a decision, it’s just useless numbers in a computer.”

One of the people who needs data to makes decisions these days is the driver.

“If you sit across from the table (from a driver) and say ‘Here’s a stack of paper, 30 pages high. I want you to read this report and it’s going to make you faster,’ some drivers are going to say ‘great’, take it, go away, and come back and they’re gonna be smarter.” Diuguid said with a laugh. “And some are going to look at you cross-eyed and say ‘What do you want me to do with this?’”

Castroneves, Diuguid said, has adjusted from being the primary data source for making the car faster to being one component of a much more technical process.

“Helio is one of those guys where, if you show him the data analysis, or you show him the video, he absorbs it like a sponge,” Diuguid said. “You can say, ‘Hey, Helio, next time I want you to go out and I want you to shift at this point or turn in at this point.’ And he does it the first time. Being able to absorb that is a huge, huge thing.”

Diuguid noted that both Honda and Chevrolet have invested heavily in computer simulation.

Advanced driver simulators that can mimic every twist and turn of a race circuit help compensate the driver for lack of on-track testing. Engineers focus on simulating even the smallest movements of the car mathematically in the computer.

A team with a good computer model of their car can test as many different setups as they have time to test. The primacy of computer simulations changes what happens when teams do get on-track testing time.

“When the series holds open tests like they did in April,” Diuguid said, “I think a lot of teams weren’t necessarily testing for balance or performance or speed. They were probably… validating models and gathering information.”

The tight competition level of today’s Indy 500 makes every team member’s contribution critical, whether they’re members of the pit crew, or engineers responsible for months of groundwork before the car heads for the track.

“If one person makes a misstep, whether it’s a pit stop or a fueler, or any of those guys, the whole thing falls down,” Diuguid said.

Castroneves has demonstrated the ability to adapt to changing conditions and new challenges. This year’s race may present the greatest test of those skills yet.