How hybrids could change the game for IndyCar’s push-to-pass

If you liked the first-time use of push-to-pass during qualifying for an NTT IndyCar Series event at the recent visit to The Thermal Club, something similar is on the way in a few months’ time.

For the sake of adding a new layer of entertainment to qualifying or the heat races at Thermal’s $1 Million Challenge, IndyCar enabled the push-to-pass (P2P) system on each car, which gave drivers 40 seconds of extra power — approximately 50hp from an increase in turbocharger boost and RPM — to use while trying to set their fastest laps.

“I thought the 40 seconds they gave you for qualifying was good because it added this pressure factor,” Rahal Letterman Lanigan Racing’s Pietro Fittipaldi told RACER. “You’re able to use 40 seconds in one lap and it gave you around six to seven tenths (of an improvement), but you have to make sure that that you don’t get traffic in the one lap. So there’s that added pressure feeling like it’s a one-lap qualifying in a way. I thought it was cool. I like that sort of feeling in qualifying.”

Fittipaldi also loved the strategy elements and risk that having a finite amount of P2P brought to qualifying.

“Definitely, with this type of boost available, I’d say qualifying could be slightly shorter,” he said. “Because the one thing you need to think about as you go on in qualifying is you have a set of Firestone and a set of , and if you only have 40 seconds or whatever to use, you’re obviously going to save those seconds for the because you’re so much faster on that one lap.

“Unfortunately, when I did my qualifying, I used all my 40 seconds and I ended up catching traffic and then the red flag came out, so when I actually set my fastest lap, I had zero push-to-pass left. Luckily, I was still able to qualify sixth, but it could have up ended a lot better for me, so you have to plan on when you go, and you might make a mistake on that lap or get traffic. I think it might shake things up.”

The allowance of P2P in qualifying was a break from tradition where its use has only been seen on race days at road and street courses. Beyond its new addition to qualifying at Thermal, RACER has also learned the choice to activate P2P in qualifying was part of a bigger fact-finding effort by the series.

Although Thermal will serve as a one-time exception with having turbo-based P2P in qualifying, IndyCar is using what came from the session at the Southern California circuit to prepare for going to hybridized powertrains this summer where added horsepower will become a standard feature in qualifying.

Once the energy recovery systems (ERS) built in partnership between Chevrolet and Honda go live, drivers will be allowed to deploy 60hp hits in qualifying through the motor generator units and energy storage systems packaged in the bellhousings. IndyCar will permit its teams to use both P2P and the ERS boost in the races, but in qualifying sessions, only the 60hp ERS punch will be allowed.

With hybrid testing continuing to take place ahead of their anticipated debut in July, rules for all aspects of how the ERS units will be used in competition have yet to be written. It’s currently unclear whether the ERS boost will be activated in all qualifying sessions, including the ovals, or restricted to road and street courses. Another matter of interest to define is if the series will limit how much ERS boost can be deployed per lap.

The latest hybrid test on the Indianapolis Motor Speedway road course confirmed that harvesting and deploying ERS energy can be done two to three times per lap, which is more than the series initially anticipated.

The fast-charging capabilities come from the choice of ESS device. Honda, which is responsible for creating and making the ESS, went with a quick-charging/low-voltage supercapacitor system that, unlike more traditional battery-based systems, is lighter, holds less energy, and can deploy and regenerate energy at a rapid rate.

Where cars in some hybrid racing series need to harvest multiple times per lap to try and fill their battery, IndyCar’s supercapacitor-based system can fill and deploy multiple times per lap. It’s here where the series is looking at placing a per-lap limit on how much ERS power can be used.

It will be a change of approach, if the per-lap limit is used, from how P2P is managed by the series where a fixed amount of P2P deployment time is given for each road and street course race. In the new world of hybridization, drivers would continue to have 150 seconds of P2P, for example, to conserve and use strategically throughout a race, and once the 150 seconds are gone, the system is deactivated.

But with IndyCar’s thought process on the ERS side, there would be no time limits involved; the 60hp boost would be on tap during every lap of the race. There could be a ceiling placed on how much ERS power can be unleashed each lap, which would make it fall in line with the mindset for P2P where the times and locations and durations of ERS power captur ing and releasing would need to have some strategy applied.