Improving the racing at Indy: How it's done, why it’s tricky

David Malsher-Lopez
·18-min read

IndyCar’s re-introduction of a universal aerokit in 2018 saw the aesthetic appeal of the series take a monumental leap forward, and also brought an end to the days of countless meaningless passes in the Indianapolis 500. All the 500s that we witnessed in the DW12 era – 2012-’14 with its standard aerokit, 2015-’17 with the ugly manufacturer kits – were entertaining, without question. But the cars ran in packs, and the passes looked too easy: the guy in front – providing he didn’t throw a vicious block – pretty much had to give way to his challenger.'

In the DW12, no one wanted to lead for long and would relinquish position to save fuel. Here the 'battle' is between Ryan Briscoe's Team Penske-Chevy and James Hinchcliffe's Andretti Autosport-Honda in 2012.

In the DW12, no one wanted to lead for long and would relinquish position to save fuel. Here the 'battle' is between Ryan Briscoe's Team Penske-Chevy and James Hinchcliffe's Andretti Autosport-Honda in 2012.<span class="copyright">Eric Gilbert</span>
In the DW12, no one wanted to lead for long and would relinquish position to save fuel. Here the 'battle' is between Ryan Briscoe's Team Penske-Chevy and James Hinchcliffe's Andretti Autosport-Honda in 2012.Eric Gilbert

Eric Gilbert

This was an ironic twist on what went before. The previous generation of IndyCars had promoted undemanding throttle-pinned-to-the-bulkhead racing at any other ovals of 1.5 miles or more, but at Indy they were tricky, finicky beasts, the kind that could give even three-time Indy 500 winner Dario Franchitti the yips during a qualifying run. They were great. 

The introduction of the DW12 in 2012 changed that. Despite Franchitti and Chip Ganassi Racing teammate Scott Dixon being clearly the fastest on raceday that year, they couldn’t break the tow to their challengers.

As Team Penske’s Will Power recalled: “The new car had sorted all the other ovals out, made them into proper drivers tracks with separation between the cars. But Indy had been turned into something of a pack race where you could not get away, even if you were faster.”

The handsome universal aerokit of 2018 – Chris Beatty-penned/IndyCar-devised – largely removed that issue, and four-time Indy winner Rick Mears welcomed the change after witnessing it in action that year. Questioned a few months ahead of Fernando Alonso’s return for a second crack at the 500 in 2019 (which descended into farce for quite different reasons), he explained the differences the two-time Formula 1 champion would discover.

The 2015-’17 manufacturer aerokits made everyone rethink their complaints about the looks of the original DW12. Here Alonso is chased by Castroneves.

The 2015-’17 manufacturer aerokits made everyone rethink their complaints about the looks of the original DW12. Here Alonso is chased by Castroneves. <span class="copyright">Scott R LePage / Motorsport Images</span>
The 2015-’17 manufacturer aerokits made everyone rethink their complaints about the looks of the original DW12. Here Alonso is chased by Castroneves. Scott R LePage / Motorsport Images

Scott R LePage / Motorsport Images

“It’s fair to say these cars put the performance back into the drivers’ hands,” Mears told Motorsport.com “so that’s always going to work in favor of the top drivers, and Alonso is a top driver. It’s that simple.

“There were moves that he – and others, I should say – made in the [manufacturer] aerokit era that aren’t possible now. That sudden movement or change of line when you’re on the limit – the last car could do that and not come unstuck. These cars need a lighter touch.

“But the upside is that drivers can feel the limit, and the best drivers in IndyCar and world champions like Alonso, they have that feel for what the car’s doing, what the right-rear is doing, how much overall grip is there, how to keep the tires under them for a whole stint.”

That said, there were complaints from certain drivers, team owners, engineers and fans in 2018 that it was now too hard to make a pass. The new superspeedway aerokit had less downforce than its predecessor but also more drag. Despite looking so much more svelte than its predecessor, the current car, by eliminating the rear wheel guards, the current car is more blunt. Consequently the lead car created a much longer tow than before, but the shape of the draft changed too.

Far better-looking, more challenging to drive, but making it too difficult to pass? The most amazing thing about the 2018 universal aerokit is that despite appearances, it actually created far more drag than its ugly predecessor.

Far better-looking, more challenging to drive, but making it too difficult to pass? The most amazing thing about the 2018 universal aerokit is that despite appearances, it actually created far more drag than its ugly predecessor. <span class="copyright">Michael L. Levitt / Motorsport Images</span>
Far better-looking, more challenging to drive, but making it too difficult to pass? The most amazing thing about the 2018 universal aerokit is that despite appearances, it actually created far more drag than its ugly predecessor. Michael L. Levitt / Motorsport Images

Michael L. Levitt / Motorsport Images

Team owner Dale Coyne – observing rather than moaning – described the tow as “more intense, but narrower, so you tow up real fast, faster than with the last car, but when you move out to pass, you just don’t pull past at a great rate of knots. The passes you have seen are coming at the end of the straights, where you come up the inside and just steal the line of the guy on the outside.”

That, according to some drivers, was just not right. One observed: “You expect the restarts to be your best chance to make a pass on a road course or street course, but that’s not what ovals should be about. If you’re shaving down your gap to the car in front, lap after lap, and you finally get there and just stall out because your car doesn’t stick – I don’t think that’s how it should be. It’s a team sport, I get it, but I don’t want to be only relying on my pit crew to get me ahead of the guy in front. Give me something to do! Give the fans something to watch!”

Before 2012, a driver closely following the car in front would stagger his approach to the turns, running half a lane higher – or lower – to get some downforce onto one front wing, one sidepod and one half of his rear wing. That didn’t work so well in 2018 nor this year, according to many drivers.

“Nah, there’s too much disturbance coming off the rear of the guy ahead,” said one of the aces, who didn’t wish to be named. “We’re just understeering. If you go half a lane lower, obviously that’s less effective because that’s the unloaded side of the car. Go half a lane higher and you’re still understeering but you’re a lot closer to going into the gray, the marbles, and then probably the wall. I think it was pretty decent last year, but the aeroscreen has given the right-front [tire] too much work again. You just have too much push for the tools [in-cockpit adjustment] to help.”

Hence the test at Indianapolis Motor Speedway this week

What needed to be done

“Right from the beginning of the 2018 universal aerokit [UAK18], we wanted to fill in the hole in the floor, the underwing,” explains Tino Belli, IndyCar’s head of aerodynamic development who works closely with Bill Pappas, VP of competition. “We did that on the short ovals and the road/street course package, because after a test at Phoenix with the old manufacturer aerokits, we proved that filling those holes made it significantly easier for one car to follow another through the turns.

“But the problem with the UAK18 on the Speedway came down to finding time to do all the safety research, because we don’t only design the car’s configuration on a superspeedway for performance. We also have very strict tests for backflips and tip-overs, and the holes are a major way to counteract that behavior when the car is at an extreme angle. We do CFD [computational fluid dynamics] analysis of the car nose-up, as if the car’s run over debris. We have equally strict criteria for how the car should behave at 90 degrees of yaw, 135 degrees of yaw as the car is coming around during a spin, and then in 2015 we added criteria for when the car is at 180 degrees of yaw – in other words, traveling backwards.

James Davison's shunt in 2018.

James Davison's shunt in 2018. <span class="copyright">YouTube screen grab</span>
James Davison's shunt in 2018. YouTube screen grab

YouTube screen grab

“So we have numbers tracking the car on the ground in all those conditions and when we originally did the universal aero kit for 2018, it was impossible to complete our research for all those conditions with the hole in the floor filled in. However, we initiated a plan late in 2019 for Dallara to research filling in the hole in the floor. We were imagining a flapper door of some sorts, so you fill in the hole but the door would come open if the nose of the car came up.

“But apart from those investigations, we also found we could satisfy our ‘nose-up’ conditions by only partially filling in the hole, the front-half. So that concept evolved and evolved and the original plan was to try these modifications around the same time as the open test at Indy in April this year. Then Covid came along and the test got deleted.

What the Covid restrictions did do is give us enough time to keep working at it. Part of the problem of filling in the holes is not only how the car behaves in nose-up situations but it also adversely affects the airflow quality. That’s the unintended consequence. So we’ve improved the quality of the flow to the point where we’re quite happy with it and even if we didn’t have the test this week, we’d feel quite confident to go forward with these parts for 2021. But still, it’s nice to have this opportunity to try these parts in the real world.”

The fluctuation in the cars’ behavior at the Speedway over the last three Indy 500s is simple to explain as Belli demonstrates.

“The UAK18 added quite a lot of front weight to the car, so we had a little bit of extra understeer in the middle of the corner in 2018. Firestone helped us fix that in 2019 with a new right-front tire. But then with the aeroscreen for 2020, we’ve put more weight on that right-front – we’re taxing it very hard – and this time Firestone didn’t feel able to help us. Well if you put more load in the right front, everyone adds more and more front wing to try and keep it in the ground rather than understeering up the track, but that wing is obviously the first thing to get into the wake of the car in front. So now you can’t get quite as close, and the more work you’re making the airflow do, the more likely it is to separate and have those unintended consequences on other parts of the bodywork.

“So the basic idea with the parts we’re evaluating this week is to shift the front aero downforce back onto the leading edge of the underwing, so that teams can run less front wing angle, and the underwing is more in ground-effect mode.”

Belli said this would not limit the number of options open to an engineer when tailoring the car’s handling balance to the taste of the driver.

Getting the front wings to work less hard, and the underwing to work harder is the aim of the latest planned changes.

Getting the front wings to work less hard, and the underwing to work harder is the aim of the latest planned changes.<span class="copyright">Barry Cantrell / Motorsport Images</span>
Getting the front wings to work less hard, and the underwing to work harder is the aim of the latest planned changes.Barry Cantrell / Motorsport Images

Barry Cantrell / Motorsport Images

“I don’t think that will be the case, no, because we’re going to leave all the front wing options that they have right now,” he said. “Since the original design we’ve added extensions and longer Gurney flaps than on the original design of the front wing. They have the asymmetric options there. And although I think that if we introduce this change we’ll mandate it, there are still discussions to be had, where we might decide to make these parts just an option.

“One of the problems you have when you have several options is that they all have to be mapped in the wind tunnel and they need to be mapped in combination with everything else. You can’t just map all the options of the front wing in isolation – they need to be assessed with the various underwing options because they all interact with each other. You could spend millions of dollars in a windtunnel getting it all mapped out, trying every permutation. So what we have to balance is giving the teams enough options that they can tune the car to what the driver needs, but not enough options that they bankrupt themselves in a windtunnel!”

Improving the racing, maintaining a meritocracy

What Belli, Pappas and IndyCar president Jay Frye have been chasing is what an IndyCar driver seeks constantly – a balance. In their case it’s ensuring the field is tight but that excellence from drivers, engineers and teams is rewarded. The purist will be pleased to hear there is no intention of getting back to an aerodynamic package that allows a car/driver to get towed around the Speedway without consequence in the wake of a car that is 3mph faster.

“There are quite large differences in opinion about what is good racing and what is bad racing,” says Belli. “I certainly wasn’t unhappy with the racing this year, but there were slightly more complaints than last year.

“If you go back to before this aerokit, the racing was very, very close but it was ‘after you’ racing – nobody wanted to lead – and so although the fans probably thought all the passing was very exciting, it was not challenging for the drivers. The driver in front would often let the guy behind pass so he could sit behind and save fuel. It was what I call peloton racing, like in the Tour de France.

“Since 2018 we’ve had real racing, so that the drivers with the best setups and who tune their cars best during the race are the guys who ended up at the front. It also creates a little bit of separation, so that you don’t have the cars running endlessly in a pack with the possibility of a massive Daytona 500-like crash. As you know, when we’re revising the aero package, safety is always number one on our list.

Belli believes 2019 saw the Indy 500 cars present the right blend of challenge and raceability.

Belli believes 2019 saw the Indy 500 cars present the right blend of challenge and raceability. <span class="copyright">Scott R LePage / Motorsport Images</span>
Belli believes 2019 saw the Indy 500 cars present the right blend of challenge and raceability. Scott R LePage / Motorsport Images

Scott R LePage / Motorsport Images

“But as we mentioned already, there was too much understeer in the cars when they got close to the cars in front, the situation was improved with Firestone’s help, but then understeer crept back this year because of the aeroscreen. So we’re aiming to get back to how it was in 2019. And it’s not easy, otherwise we’d have done it already. For Dallara this was almost a year’s work in CFD and the windtunnel, checking airflow patterns, and stability and so on at the various degrees of yaw and nose-up.

“Actually we’ve added to the work with other boxes to be checked – 90 degrees of yaw with 45 degrees of tilt, with no front wing, broken left-front suspension, broken left-rear suspension… Remember, one of the things that crept back in 2019 was that after a car found the wall, it would turn back to 90 degrees of yaw and start to tilt up – what I’d call a semi-flip. We didn’t have that condition this year, but all these new parts needed to meet our requirements for trying to improve those conditions as well. Any new part you come up with for the Indianapolis Motor Speedway requires six CFD cases for stability as well as the one case for straight ahead. So it’s six times the amount of work for every part you want to consider putting on a car, compared with four years ago. As you can imagine, it slows down your rate of development to 17 percent of what it used to be.”

IndyCar’s ethos going forward is clear, then. As Belli puts it, “Our responsibility to the drivers is to make each change as safe as possible and our responsibility to the fans and the teams is to keep the racing entertaining. And then within the teams, we want to still give the engineers enough latitude so that they can still make a difference.

“Ultimately, we want the best drivers and the best teams to win the races, but not to have everyone so strung out that they can’t run close. We don’t want the passes to be easy because then anyone can do it. We had that era. Passing should be possible but challenging, and I think we got the balance of that at Indy correct in 2019. I think a lot of people appreciate that a pass that isn’t completed can be as exciting as a successful pass.”

Formula 1's DRS passes at Portimao last weekend were far too easy, says Belli.

Formula 1's DRS passes at Portimao last weekend were far too easy, says Belli. <span class="copyright">Glenn Dunbar / Motorsport Images</span>
Formula 1's DRS passes at Portimao last weekend were far too easy, says Belli. Glenn Dunbar / Motorsport Images

Glenn Dunbar / Motorsport Images

It’s a fair point and one that is often forgotten – that being able to defend (within the rules) is as important a racing skill as the ability to attack. It rarely earns the same praise, just as a great catch in baseball or a great save in hockey won’t earn the same plaudits as the guy who knocks it out of the park or scores a great goal. IndyCar isn’t aiming to make passing easy nor defense impossible.

Belli observes: “In Formula 1 this past weekend [at Portimao], there were plenty of passes made with the DRS system that seems unfair. You give the guy behind all of the advantage and it doesn’t even look like a challenge. The beginning of the race was awesome because of the weather – Kimi Raikkonen and Carlos Sainz were pretty spectacular – but after that the passes were just gimmes, and I don’t think a pass should ever be a gimme unless the car ahead is limping because the driver made a mistake, tapped the wall or something.”

Oval aero changes beyond Indy

Aero changes coming for Gateway.

Aero changes coming for Gateway. <span class="copyright">Phillip Abbott / Motorsport Images</span>
Aero changes coming for Gateway. Phillip Abbott / Motorsport Images

Phillip Abbott / Motorsport Images

The Indy 500 aero package is not the only one that requires work, according to Belli, who next year will ‘only’ need to consider the 2.5-mile IMS, the 1.5-mile Texas Motor Speedway and the 1.25-mile World Wide Technology Raceway at Gateway. Texas becomes a double-header, but the wonderfully challenging 0.894-mile Iowa Speedway is gone, and Richmond Raceway’s three-quarter-mile track – slated to return this year but a victim of the pandemic – isn’t on the 2021 schedule.

“We were very happy with what we had at Iowa,” says Belli, “so it was disappointing to see that one go away. But that leaves us with Texas and Gateway which are up for discussion. The first Gateway race was fine, but then the second one wasn’t – and everyone only remembers the most recent! We don’t turn a blind eye to any of them. It’s like race distances at the Harvest Grand Prix: one race was brilliant, the other one wasn’t because we’d played with the race distances [the second one was 15 laps shorter, allowing drivers to make it on a fuel-saving two-stop strategy].

“It’s sometimes a moving target though. Going into St. Pete, everyone said it would be a fuel saving race, a two-stopper, but you get a caution period or two in there and suddenly what was a fuel-saving race opens up. Basically, you need to set the race distance by how many yellows you’re going to have! That would require a formula that’s adjusting the race length all the time according to how many laps the cars run under caution…

“But to your point, we need to look at Texas Motor Speedway with particular attention to the tire issue we’ve had since it was resurfaced in the 2016/2017 off-season. We’ve had difficulty doing full stints on tires since then, and I think we’d like to tighten it up a little bit.

“Gateway is more difficult, because we’ve tried the low downforce short-oval package that worked so well at Iowa, and we’ve tried a high-downforce configuration because our first race back there was in 2017 with the manufacturer aerokits, and we really had the same sort of racing. So maybe the answer’s not all in the aerodynamics at that track.

“But that’s what we’re all about – engines, tires and aerodynamics are within the sphere of what we can adjust – and it’s our job to get the level of entertainment and challenge that everyone wants.”