Aside from the occasional aero misstep on ovals, the last three years of the NTT IndyCar Series have been a treat to watch. The handsome IndyCar-devised, Chris Beatty-designed, Dallara-built 2018 aerokit, with its emphasis on underfloor downforce and upper surfaces that are ‘clean’ by most open-wheel standards, have allowed cars to follow closer, have reduced overall grip, and given the drivers more feel.
And if the aeroscreen looks like a giant welding mask when viewed from head-on and its weight and consequent c.o.g. shift forward has made the cars a millisecond more ponderous on initial turn-in, well, the car looks good from other angles, the drivers are safer, and the best of the racers and engineers – as they always do, despite initial misgivings – have adapted to the new handling traits. Crucially, so too has Firestone, despite more energy being put through the car’s front wheels.
But in 2023, a new engine formula arrives, and the current 2.2-liter V6 twin-turbo units will be replaced by 2.4-liter V6 twin-turbos supplemented by a KERS [kinetic energy recovery system], as IndyCar seeks an ultimate target of 900hp engines for road and street courses. How quickly it can reach this target is open to question, but some experts in the paddock believe IndyCar president Jay Frye’s original prediction of 2025 was spot on, despite the new regs start date being pushed back by two seasons.
The fact that the KERS power boost will be available on ovals, too, may raise a smirk with anyone who recalls the reaction to the idea of push-to-pass boost on ovals. Back in the darkness of the manufacturer aerokit era, 2015-’17, cars that looked as if they were carrying large parts of their own packaging material were struggling to pass on short ovals. The ugly aero packages generated immense downforce in the turns and immense top-surface drag on the straights so that the disparity between turn apex speed and straight line speed was pinched tight.
So in desperation for good racing on the sub-1.5-mile ovals, the idea of adding push-to-pass boost for the short ovals was aired… but eventually shot down. According to Frye, the engine manufacturers had been OK with the idea, but the majority of drivers voted not to go ahead with the concept, worrying about the idea of the extra power abruptly shutting off around turn-in, thereby unsettling the car in its crucial transition phase.
This seemed… curious. From the start of 2017, the push-to-pass boost was changed from a number-of-uses system – whereby each squirt lasted a 15 or 20 seconds, depending on the circuit, and if the driver backed off the gas or hit the brakes he’d waste whatever was left over – to an overall time-allowance system, whereby the driver could back out of a passing attempt mid-flow without wasting additional seconds of extra boost. In other words, a driver’s deployment of the race-long total of extra-boost seconds was entirely in his hands, so if he didn’t want the car twitching if its boost reduced as he turned in, he just needed to come off the boost sooner…
“Some of these guys just want the series to save them from themselves,” chuckled four-time Indy 500 winner and three-time champion Rick Mears. “Are they gonna complain next year when we reduce downforce so they have to ease off the gas for the turns? Well, yeah…probably! Unfortunately, whenever a change is made, a lot of people instantly react, ‘We can’t do that. That’s too dangerous.’ And then they realize it’s the same for everybody, they adapt, and the complaining stops.”
And so here we are, come full oval, with IndyCar ready to set its KERS to provide short-duration 100hp boosts on left-turn-only tracks as well as road and street courses. Tomorrow, two Chevrolet cars (Josef Newgarden/Team Penske and Pato O’Ward/Arrow McLaren SP) and two Honda cars (Scott Dixon/Chip Ganassi Racing and Alexander Rossi/Andretti Autosport) will hit the iconic 2.5-mile Indianapolis Motor Speedway to simulate the effects of the hybrid unit.
Motorsport.com asked IndyCar’s much respected VP of competition Bill Pappas about the methodology of the test, and how it will guide the series’ decisions over the plans for 2023.
DML: How do you simulate the effects of a hybrid unit deploying its extra power?
BP: The four cars will run at 1.3-bar boost, like we normally race at Indy, but we’ll simulate the power we’re aiming for from the electric motor by allowing the guys to turn the power up – for short durations – to 1.5-bar, which is what they run there at the 500 on Fast Friday and in qualifying. [Road and street course boost is currently 1.5-bar standard, with 1.65-bar on push-to-pass]. We’ll see how that works in terms of making passes, where the passes occur and see what the drivers think of it.
Obviously a car that’s had the boost turned up for a certain amount of time will then turn the boost back down to represent how the electric motor will be recharging after discharging. Then a driver behind who’s chosen to use his power in a different way can catch back up if he hits the electric motor – or in tomorrow’s case, the extra boost – at a different point of the run.
And what’s the plan for how long you want the KERS unit to provide this extra power before it needs to recharge?
We’re still doing simulations on the duration of recharging and storing the energy, and whether you discharge all at once or in squirts. It hasn’t yet been finalized, but there is of course a limit to discharge and recharge times. So there are a couple of modes for the drivers to try tomorrow morning, and we’ll determine what’s best when we talk to them after a couple of hours, and decide how to move forward through the afternoon.
One of the complaints about the current push-to-pass system is that teams can see on their timing screens when a rival car is using its extra boost and can therefore instruct their driver to do the same in defense, thereby negating the whole point of it. Do you plan to remove that data from the screens?
Ha, well that’s been discussed since I got here [five years ago], and with this hybrid… it’s still to be decided. I don’t think we’ve thought that far yet.
But it’s probably more crucial with this system than with the push-to-pass turbo boost, because I assume when a driver sees the car behind gaining on him, and he hits the KERS, the response is that much faster than whacking up the turbo.
Oh yeah, it is immediate, instant power to the wheels. But how much have you stored to come back against someone? Right now with the turbo boost, we have a fixed value of power in order to push to pass – or defend! – but with the hybrid system, you may have used it on the back stretch to get to your current position and now the guy behind is coming up on you and you may have nothing to respond with until it’s recharged.
Back in 2017, you tweaked the push-to-pass system so that its use wasn’t defined by the number of hits, but instead the driver controlled the duration of each hit up to a total of 150 or 200sec. I’m assuming the KERS will continue that latter policy.
Correct. Yeah, there won’t be delivered in timed increments. It will be entirely up to the driver as to how much of the stored energy is used in any given burst – 20 percent, 50 percent, all of it – that’s up to him. So he might think, “OK, I only need to use 20 percent of it here on this short straight to get on the tail of the guy ahead, but I’m going to have to use the remaining 80 percent down the long straight three corners away in order to try and pass him.”
So it’s going to be a different way of utilizing this added power, and unlike push-to-pass, it’s going to be available throughout the race – no time limitation – other than the recharging time, obviously… A driver can recharge and discharge every lap.
That’s going to make the sprint from the final turn to the checkered flag pretty interesting…
Oh yeah, it’s going to be quite exciting, once we get the system in and watch the different teams and drivers optimizing it and strategizing with it. Should be pretty cool. Think of the hit of extra boost coming out of that tight final hairpin at Long Beach, or the long drag uphill from the final turn at Road America. Or Portland – that front straight is a dragstrip!
But with electric power feeding in instantly, it’s going to be about where you hit the button, right? If you suddenly get an extra kick of 100hp coming out of a 40mph hairpin at Long Beach, you’re going to be sliding sideways as well as going forward.
How close are the cars going to be to that magic 900hp mark?
With the electric motor deployed, I think we’re going to be close to that on road and street courses, considering the engine guys are also going up from 2.2-liters to 2.4. I really think it’s going to be impressive.
Will there remain the disparity in turbo boost between the big ovals – 1.3-bar – and the road/street/short ovals – 1.5-bar?
For the start, yes, we have to, just out of commonsense. Can’t be hurtling around Texas or wherever else we go to with 900hp. You’ll still have the same 100hp electric power on the ovals, but the engine power will be detuned, yes. Once we get through durability testing and discussions with the engine guys, we’ll make the decision regarding specific turbo boost levels, but at this point, we’re looking at those two numbers – 1.3- and 1.5-bar. That’s tunable, we can change that.
When can we expect to see the 2.4-liter hybrids first hit the track, and will the testing be IndyCar-regulated, whereby each manufacturer runs together?
Yeah, the testing plan will run the same way that Chevrolet and Honda were brought into the series with the current 2.2-liter engines in 2012. Both will run at the same time, it will be relatively controlled, and I’d say middle of 2022, they’ll be ready to start testing. It should be pretty straightforward – V6 twin-turbo like the current engines, so the architecture stays pretty much the same.