Track testing of the new 2.4-liter twin-turbo V6 hybrid engines made by Chevrolet and Honda has been pushed to the offseason at the behest of both manufacturers. Prior to the change, the maiden hybrid test was due to be completed before the end of July.
Set to debut in 2024, the rival brands conducted their first road course test with the 2.4-liter motors in April at Indianapolis without energy recovery systems designed by MAHLE. Having recently received the 100hp systems that make use of a motor generator unit mounted behind the engine and a supercapacitor-based charging and deployment device, RACER understands early dyno testing with the ERS units connected to the internal combustion engines revealed problems within the bottom ends of the twin-turbo V6 motors.
A need to redesign the crankshafts and fortify the main bearings was said to be at the root of the testing delay. Manufacturing new crankshafts for IndyCar engines can take quite some time under normal production timelines, and with significant new supply chain issues being faced in receiving the raw materials to machine, delays of six months or more have been cited.
Altogether, the time needed to produce revised solutions has led the first ICE+ERS track test IndyCar had penciled in for late July to be rescheduled for late September or October on the Indianapolis road course.
“We’re working towards hitting different landmarks with the full hybrid engine system before we go testing,” IndyCar president Jay Frye told RACER. “Once we get there, then we’ll start worrying about track testing. And there’s never been a rush to go to the track. We want to get it right, get it done, and then go to the next step in the process.
“What’s been going on lately is we can say that both manufacturers have had the same issue. So that’s good, right? That helps accelerate the whole process. If one had a problem with one thing, and one had a problem with another thing, that might create more concern. But so far, anytime something’s happened, it’s been relatively consistent amongst both of them from a hybrid perspective. And they’ve both been very open with us and with each other to get the issues fixed.”
Since this story was first printed, HPD and Chevrolet have both reached out to RACER to strongly refute the notion that crankshaft or main bearing problems are responsible for the delay.
Noting the long runway until the hybrid engines go live for their first race, Frye says the delay is not a concern.
“They’re not hitting the track to race until March of 2024, so we want to make sure we do everything we can prior to going to do a track test,” he reiterated. “The more of those things that we can do now in the dyno at Honda, at Chevy, versus doing it on a track, because going to track test is very expensive — we’re glad to wait if that’s what’s best for our OEMs. The more stuff that you can do and learn first in a laboratory environment, the better.”
NOTE: This story has been updated since original publication to include a response from the manufacturers.