In theory, IndyCar’s 2023 hybrid plan
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Marshall Pruett | February 2, 2022 11:49 AM ET
This story first appeared in the Winter 2021/2022 issue of RACER magazine. Click here to get your copy, or set yourself up for a full year of stellar motorsport writing and photography with a print or digital subscription.
It took the better part of two years to chase down some of the answers surrounding the NTT IndyCar Series’ most secretive project.
Announced on May 19, 2018, IndyCar declared its intent to move forward with a new 2.4-liter, V6 formula in 2022, up from the 2.2-liter motors in service since 2012. But an addendum on Aug. 1, 2019, pushed the larger internal combustion engine’s arrival to 2023. And for good reason, as the series put out a call for vendors to submit their ideas for a spec energy-recovery system to complement the robust twin-turbo motors. With a change of electronic heart, IndyCar would introduce its first hybrid powertrain.
And while Chevrolet and Honda have been beavering away on fashioning their new mills to make 800-plus horsepower, the identity of IndyCar’s chosen ERS provider, along with every other aspect of the system, has been kept under lock and key. But thanks to a growing number of hints and innuendo, RACER has put the clues together and followed the trail to Stuttgart, Germany, home of renowned racing piston manufacturer MAHLE.
Unbeknownst to most of the racing world, MAHLE does more than make precision engine componentry. Separate from its racing heritage, MAHLE’s vast e-mobility division is more than capable of supplying IndyCar with an ERS solution. And with its recent signing to supply the DTM series’ upcoming electric championship with all manner of technology, MAHLE will be busy on two fronts with its homegrown e-touring car series and an American open-wheel championship to support.
MAHLE is already partnering with Germany’s DTM for its upcoming all-electric series.
Although IndyCar is not prepared to discuss its ERS solution in any detail just yet, we’ve learned enough about the impending system to warrant a proper download of our findings, all with the proviso that everything you’ll read from hereon is subject to change and final confirmation.
SUPERCAPACITOR ROUTE
Rather than accept a proposal for a more common battery-based ERS unit, or the formerly-fashionable flywheel style of storing energy, multiple sources say IndyCar has accepted MAHLE’s proposal to use a somewhat rare supercapacitor-based ERS solution.
The highest-profile use of supercapacitors in racing was from 2014-’15 in the FIA World Endurance Championship, when Toyota’s first iterations of its TS040 LMP1 HYBRID made use of an in-house system developed by DENSO and Nisshinbo. Later, the manufacturer also publicized its switch to a battery-based ERS unit to store and deploy energy, which continues in its latest GR010 Hypercar.
Supercapacitors aren’t new to top-level racing. Toyota’s TS040 HYBRID LMP1 car used one for storing recovered energy.
Of the benefits associated with a supercapacitor, its ability for rapid charging stands well above the other ERS options. In an IndyCar application, that swift recharging would be the main reason to choose a supercapacitor to handle the energy being harvested through the rear wheels under braking. How much energy will be stored, and the duration and profile of its release, are yet to be confirmed, but peak boost is set to be around 100hp.
THE OVAL CONUNDRUM
If finding out the ERS supplier’s identity was our first priority, the second was determining how IndyCar plans to recharge its ERS units at the Indianapolis 500 and on other ovals, where traditional harvesting under hard braking isn’t an option.
Assumptions that a second ERS unit would be required for the ovals – using similar or identical technology to the MGU-H systems found in Formula 1, in which exhaust energy that spins turbocharger turbines is converted into electricity – appear to be misplaced.
Provided the current plans hold, IndyCar intends to rely on a single MAHLE supercapacitor ERS unit to serve all of its track types. For road and street courses, regeneration would occur under braking – so far, so familiar. On the ovals, that same rear-braking system would be triggered through a harvesting paddle attached to the steering wheel. Drivers would squeeze the paddle to apply light rear braking with their fingertips. And while the paddle would be new to IndyCar, it’s far from uncommon.
Look on the backside of the steering wheel in a Chevy Bolt EV road car, and a similar charging paddle can be found; it serves as a useful, finger-operated tool to brush the brakes when traffic briefly slows on the highway, or in other scenarios when a full stab at the brake pedal isn’t required. But this isn’t a totally new concept to motorsports: Some of the former LMP1 Hybrid prototypes had a similar steering wheel-mounted device, while Formula E makes significant use of a regeneration paddle, where its drivers squeeze the lever and activate braking and charging of their batteries, often while coasting.
Where a harvesting paddle makes particular sense at the Indy 500 is in the routine situations when drivers are clustered together in the draft and lifting off the throttle to maintain a safe distance to the car ahead. Just as a Bolt owner would use the paddle to scrub a few miles per hour off on the highway, it’s easy to imagine IndyCar drivers doing the same entering Turns 1 and 3 throughout the 200-lap race, trading throttle lifts for short charging bursts from light plucks of the harvesting paddle.