Testing imminent for 2028 IndyCar

The IndyCar Series’ new-for-2028 chassis and engine combination is expected to turn its first laps of validation testing within the next two weeks.

Multiple sources have told RACER to look for the Dallara IR28 powered by a 2.4-liter twin-turbo V6 engine to complete its maiden laps in the gap between today's race at Nashville Superspeedway and the next event on the calendar at Portland on Aug. 9.

No specific date has been shared, but the last day(s) of July and the first day(s) of August have been mentioned as the most likely window for the shakedown to take place. If the test faces any delays, it would likely be moved until after the season concludes; five straight weekends of racing is scheduled from Portland through Laguna Seca on Sept. 6, leaving no time for extracurricular tests during this span.

The location also awaits confirmation, with Sebring’s short course in Florida – a highly popular testing destination for Indy cars dating back to the 1980s – and the Indianapolis Motor Speedway road course having been floated as possibilities.

Once a date and venue are solidified, the first Dallara IR28 prototype is expected to be put through a highly structured and controlled series of systems checks to ensure the car does all of the basics with accelerating, braking, shifting, turning and other simple items to confirm or fix before attempting to make speed.

As soon as the car has covered the basics, more robust runs will commence as Dallara and IndyCar attempt to validate all aspects of the IR28’s suspension, bodywork, electronics and the rest of the items Dallara and its many subcontractors will need to mass produce as 100-plus cars are ordered and manufactured by the Italian firm.

The purpose of the validation testing is to prove all aspects of the design perform and interact with each other as expected. If any problem areas emerge, redesigns will be carried out and new prototype pieces will be put through additional validation tests until the IR28 receives its sign-off by the series and Dallara. Once that is achieved, an intensive production process will begin where teams and their 27 total entries will begin receiving cars in 2027 to begin their own testing programs while contesting the final championship outing for the Dallara DW12.

While new, the 2.4-liter twin-turbo V6 engine formula that will replace the current 2.2-liter twin-turbo V6s is the same that was built and tested by Chevrolet and Honda in 2022. Although the integration into the IR28 chassis is new for the 2.4L motors, the slightly larger and higher power motors are not new like the IR28 and in need of the same extensive validation testing by Chevy and Honda.

The IR28, like the DW12 since June of 2024, will race with an energy recovery system fitted inside its bellhousing, and will feature a new and more powerful "hybrid unit," but it is not expected to be in the IR28 for its early tests. Ballast placed in the bellhousing to replicate the weight of the hybrid is understood to be the likely solution until the prototype units are ready for track testing.

Drivers for the first tests have not been named, but based on previous new-car rollouts, leading drivers from Chevy- and Honda-powered teams would be expected to assist Dallara and IndyCar with the project.

To date, the series has not revealed images of the IR28.