After multiple delays, the NTT IndyCar Series is finally set to introduce a hybrid powertrain at this weekend’s race from Mid-Ohio.
All 27 cars will be fitted with electrified power units that will complement the established 2.2-liter internal combustion engines to deliver over 800 horsepower to the rear wheels.
Although IndyCar is far from the first racing series to incorporate hybrid power into its formula, it has developed a unique configuration that could help it stand out. As long as the technical achievements incorporated into the cars are noticeable, that is.
It has been a long road to get to this point. IndyCar first started developing a complete hybrid package by working with MAHLE, one of the largest automotive parts suppliers in the world. They designed and built prototypes for a system that would fit inside the bellhousing of the series’ existing Dallara DW12 chassis.
A lot of work was done on the system, but there were multiple hurdles that cropped up once it came time to start running tests on actual race cars on track. Reliability issues were present once the systems were exposed to real world conditions, and lingering supply chain issues that hung around years after the pandemic threatened the ability to properly supply the entire grid.
In late 2022, just a few months before the planned hybrid introduction at the start of the 2023 season, IndyCar announced that implementation would be delayed to 2024. In addition, development of MAHLE’s initial designs were brought in house, meaning the series’ existing engine manufacturers Honda and Chevy took over the project.
The two companies worked together to finalize the design, Honda taking the lead on the energy store and Chevy the motor generator unit, and together have presented a complete unit that will bring hybrid power to America’s top open wheel series for the first time.
The first complete systems tests were run on August 16, 2023. Series veterans Scott Dixon and Will Power completed laps around Sebring International Raceway, and helped a fleet of engineers evaluate performance and make decisions about the best way to solve problems that arose.
As more completed units were produced, further tests were held later in the year at a variety of tracks with an increasing number of teams. IndyCar’s smaller teams were forced to wait until March 30 of this year before they were able to sample the system for themselves, after some 15,000 miles of testing had already completed by the series’ big names.
This led to some calls of unfairness, but the larger teams and their veteran drivers consistently stated their participation in the early testing only helped Honda and Chevy finalize the system, and did not produce an unfair advantage.
“It’s just different,” said Newgarden, dismissing the concerns. “It might suit people, and it might not suit others. It’s certainly something you have to adjust around driving-wise, setup-wise, so we’ll see who copes the best. I don’t think it really matters [at what point the hybrid is introduced].”
The system functions with the same basic principles of other automotive hybrid systems around the world, with an electric motor placed in-line on the driveshaft that can double as a regeneration unit as well. The motor delivers power under acceleration and harvests power under braking to help recover energy that would normally be ‘lost’ as heat in the car’s brakes.
Where IndyCar’s system differentiates itself is in the compactness of the completed unit. The electric motor, energy store, and relevant control electronics all fit within the chassis structure between the ICE motor and the gearbox, and weigh just over 100 pounds.
Another area that is unique is the way in which the system stores energy. Instead of chemical batteries or spinning flywheels, energy is stored in a pack of 20 soda can-sized supercapacitors. These supercapacitors can receive and discharge energy quickly, and can be subjected to many cycles without degradation.
The design choices also allow the system to run at approximately 48 volts, with a safety cap at 60 volts. Implementations in other series can have much higher voltages, with IMSA’s GTP prototypes containing electric systems that run at 700-800 volts for example. IndyCar’s lower voltage numbers will keep drivers, crew, and track workers safe without any new extreme safety procedures having to be introduced.
Although the hybrid systems are delivered to the teams as spec units with no room for physical adjustments, there are a few options that will be made available to drivers. Regeneration in particular can be accomplished by a paddle on the steering wheel, allowing for fine adjustments in regeneration rate, or automatically under braking through software settings.
Deployment will be done via a dedicated button on the steering wheel, which will allow drivers to decide when best to use the extra power boost from the electric portion of their power units. The deployment will be in addition to, and separate from, the existing Push to Pass system that increases the engine’s turbocharger boost pressure to temporarily increase power to the rear wheels.
There are limits that will be imposed by the series, which will be quite restrictive for the first few race weekends. Although the hybrid system will be allowed to be used during qualifying, race starts, and restarts, IndyCar will limit the amount of instantaneous power delivery from the electric motor and will also limit total usage by setting a maximum energy use per lap.
For the hybrid system’s debut at Mid-Ohio this weekend, drivers will have 50-60 horsepower at their disposal and will only be able to deploy the boost for four to five seconds per lap. Once the limit of 280kJ of energy is reached, they will have to wait until the next lap to deploy the system again.
The system is technically capable of supplying quite a bit more power, but IndyCar officials are taking a conservative approach during the first few races to ensure there are no reliability issues that ruin a driver’s race weekend. Extra scrutiny will be applied to any problems that arise, especially considering the system is being introduced halfway through the championship season.
“The system doesn’t really do much,” admitted Pato O’Ward to MotorsportWeek.com. “In terms of performance, you’re definitely not looking at over a tenth anywhere. It doesn’t bring enough performance for it to be actually different in terms of the outcome. You feel the burst, but does it actually translate to performance? Maybe a little bit.
“I think over time, as we learn how to extract more from the unit, I think it will improve. Where we’re at right now, in terms of what limits we can use, there’s not enough. You can’t hear it, you can’t see it. There’s been so much money put into this, time and effort. The fan will notice absolutely nothing.”
Ironically, the biggest change fans may notice is the ability for drivers to restart their own cars if they stall on track. The new electric motor can serve as a starter motor, and the trackside safety crew will no longer have to intervene if a car is stalled following a spin.
This little detail will lead to fewer caution periods throughout the weekend, and could change the pit strategy teams employ if they are expecting longer green flag runs during the race.
But make no mistake, having hybrid powertrains is a big deal for the health of the series. Road relevance is as important as ever, and companies need to be able to demonstrate that on track technologies are helping their business dealings with the general public.
Honda was one of the most adamant of IndyCar’s partners that the series get a working hybrid system in the cars this season. The company was even rumored to have made a demand that hybrid systems be introduced before the end of the 2024, or they would stop supplying the series with engines. A threat made more credible by public comments the company made lamenting the costs associated with operating its IndyCar program.
Whether or not that was the main factor in the decision to introduce the hybrid system mid-season may never be made public, but the result is the same either way. Fans will get to see a hybridized IndyCar for the first time this upcoming weekend, and will witness the biggest technical change to the series since the Aeroscreen debuted in 2020.
There are nine races left in the current season, which will show which teams and drivers are able to adapt to the new regulations best. Those nine races will also serve as the ultimate test to see if all the hard work pays off for a series that could desperately use a positive storyline.
Considering the 2026 F1 is looking at 400+ from the Hybrid, the Indy system looks rather modest. My road going hybrid Porsche adds 140 BHP and 250 Nm of torque from the electric motor and that torque can be multiplied as the electric motor is before the 8 speed PDK gearbox unlike most electric motors which are direct drive.