INDYCAR IR-28: The New Battery, Suspension and Hybrid Technology Explained

INDYCAR has unveiled the IR-28, the chassis that takes the NTT INDYCAR SERIES into 2028, and the real story is buried in the bellhousing. For the first time in INDYCAR history the hybrid system will run on a proper battery, not a supercapacitor, supplied by a company that builds energy storage for Formula 1. Sitting alongside it is a new hybrid drive unit from Helix, a UK operation with a client list that already includes Formula 1 and Formula E teams. INDYCAR has recruited suppliers with existing Formula 1 and Formula E experience to build the heart of its new hybrid package.

Key Points: INDYCAR IR-28

• IR-28 renderings unveiled via a video trailer narrated by Matt Damon. The chassis is due to make its competition debut at the start of the 2028 season, with initial track testing beginning this week
• IR-28 is the first NTT INDYCAR SERIES chassis to run a battery-based Energy Storage System, replacing the current supercapacitor
• BOLD Technology, headquartered at the Circuit de Barcelona-Catalunya and expanding into Michigan, supplies the ESS. It delivers roughly 14 times the energy storage capacity of the current system
• Helix, a UK-based hybrid systems company with existing Formula 1 and Formula E clients, joins as INDYCAR’s new hybrid drive partner, its unit packaged inside the bellhousing
• The car sheds around 100 pounds overall (roughly 45kg), with the hybrid unit and new Xtrac gearbox both contributing lighter components within that total
• A new AXIS Inertance Control Suspension System makes INDYCAR the only major motorsport championship permitting both front and rear third-element inertance

What INDYCAR Unveiled

What landed this morning was renderings, not a running car. INDYCAR shared the first images of the IR-28 through a video trailer narrated by Academy Award winner Matt Damon, built with Dallara after what INDYCAR President J. Douglas Boles described as a lengthy planning and collaboration process across the series’ partners. The chassis carries a modernised, more aggressive look, with new front and rear wings, a redesigned aeroscreen and a superspeedway wing configuration built for Indianapolis Motor Speedway specifically.

Initial on-track testing begins this week across a range of circuits, including the Indianapolis Motor Speedway road course and oval, and Sebring International Raceway. The IR-28 will not make its competitive debut until the start of the 2028 NTT INDYCAR SERIES championship. Everything else in this piece, the battery, the suspension, the engine formula, sits behind that timeline. None of it is proven on track yet.

The Battery Leap

Every current-generation INDYCAR hybrid system has stored its recovered energy in a supercapacitor. The IR-28 changes that completely. The new Energy Storage System is battery-based, the first of its kind in series history, and it comes from BOLD Technology, a company headquartered at the Circuit de Barcelona-Catalunya that is now expanding its operations into Michigan. BOLD builds battery systems for Formula 1, aerospace and defence applications. INDYCAR selected them for the IR-28 programme on that strength.

The number that matters here is roughly 14 times. That is the increase in energy storage capacity the new ESS delivers compared with the current supercapacitor system. Supercapacitors are fast to charge and discharge but hold relatively little energy. A battery-based system holds far more. That gives INDYCAR room to build more varied deployment rules, though what drivers are permitted to do with that capacity will come down to the sporting regulations, output limits and regeneration profile INDYCAR sets around it. Storage capacity alone is not the same as deployment freedom.

None of that capacity gain has come at the cost of weight. The complete hybrid system, including the ESS, is around 20 pounds lighter than INDYCAR’s current hybrid package. INDYCAR describes it as engineered and qualified to the most stringent motorsport safety standards.

Helix, Xtrac and the Weight Reduction

The hybrid drive unit itself comes from a new name in the INDYCAR paddock. Helix is a UK-based company describing itself as a global leader in next-generation electric drive systems, with a client list that already includes teams in Formula 1 and Formula E, and experience across high-performance road-car programmes. Helix’s hybrid design for the IR-28 is packaged inside the bellhousing, located between the combustion engine and the gearbox.

Xtrac, INDYCAR’s exclusive transmission supplier since 2000 and a Helix associate, is providing the new gearbox. It sheds 25 pounds from the current unit. Both that gearbox saving and the hybrid unit’s 20-pound reduction feed into the IR-28’s wider target of around 100 pounds lighter overall, roughly 45kg, with the rest of the saving coming from the redesigned chassis and other systems.

The Suspension Technology Explained

The new AXIS Inertance Control Suspension System is built around a lightweight, shared damping architecture, expanding spring, damper and inerter tuning without adding cost. In general suspension engineering terms, a third element sits across an axle to control combined wheel movement, heave and pitch, using an inerter that resists changes in suspension motion rather than acting like a conventional spring. Running that at both the front and rear of the car gives engineers another tool for managing the platform over bumps, under braking and through aerodynamic load changes.

INDYCAR is now the only major motorsport championship permitting both front and rear third-element inertance systems. That gives the IR-28 a suspension configuration not currently permitted elsewhere in major championship motorsport.

Chevrolet and Honda Commit to 2028

Chevrolet and Honda have both committed to INDYCAR’s new engine formula, a 2.4-litre twin-turbocharged V6 capable of producing up to 760 horsepower. Both manufacturers frame it as the next chapter of a decades-long INDYCAR relationship rather than a fresh start.

The IR-28 combines a new battery, a new hybrid drive unit, a lighter gearbox, a new suspension platform and this new engine formula in one development programme. What that combination does against a stopwatch will not be clear until the car is on track.

Coffee Corner Take

The headline out of this launch was always going to be the way the car looks. Matt Damon narrating a trailer will do that. The more interesting story is sitting in the bellhousing, not on the bodywork.

Bringing in BOLD Technology and Helix for that job says something about where INDYCAR wants to sit technically. Both companies build for Formula 1. Neither has built for an American open-wheel series before now. Going out and recruiting that specific kind of supplier, rather than developing the capability in-house or sticking with the existing supercapacitor system, is a statement about ambition as much as it is about hardware.

But a 14-fold jump in storage capacity is a spec sheet number until INDYCAR confirms what drivers are allowed to do with it. Maximum deployment power, energy use per lap, whether it is manually controlled or software managed, how fast the battery regenerates: none of that is in today’s release. That is where the real strategic story sits, and it is the part testing needs to start answering, not the number on its own.

The suspension change deserves more attention than a launch release usually gets it. Running a third-element inertance system front and rear is a serious engineering statement on its own, independent of the battery story. Whether that translates into closer racing depends on how teams use it once cars are on track.

Renderings and press releases are not lap times. The IR-28 will not turn a competitive wheel until 2028. Everything here is a promise. Whether Indianapolis gets its first new qualifying record since 1996 is a question testing, not marketing, will answer.