With dwindling car counts in the GS class and aging machinery in the ST ranks, IMSA is evaluating the future class structure of the Continental Tire SportsCar Challenge, with wholesale changes possible for as early as next year.

Speaking with Sportscar365 last weekend at Mazda Raceway Laguna Seca, IMSA President and COO Scott Atherton and CEO Ed Bennett revealed they are seeking input from stakeholders to help shape the future of the series.

Bennett said the concept of self-built race cars, which had largely made up the Continental Tire Challenge grids in recent years, appears to be on the decline, impacting car counts.

“This era of production cars being converted into race cars — as much as we’ve enjoyed it and it’s been great for a lot of individual shops and guys to do that — there’s just not currently as much demand to do that,” Bennett told Sportscar365.

Instead, IMSA is looking to potentially integrate globally recognized platforms into the series, which could provide stability and a more cost-effective solution for competitors.

Outlined in a memo sent to competitors last weekend, IMSA said it is considering the LMP3, GT4 and TCR platforms, not only for Continental Tire Challenge, but potentially other series under its umbrella as well.

With some GT4-based cars already competing in GS, Atherton said a switch to full GT4-spec machinery would appear to be “low-hanging fruit” but stressed that a decision has not yet been made.

“Industry trend wise, it’s obviously there in terms of performance, with GT4 cars already competing [in GS],” he said. “It makes a lot of sense.

“I don’t want to make it seem like we’re jumping on the bandwagon. But I think we’re a more complex example than some of the others that are operating in GT4 mode right now.”

While the GS class saw a seven-car grid in Monterey, ST, meanwhile, continues to be thrive, with 27 cars having taken the green flag, including a new BMW 288i.

Despite continuing to be an attractive platform, although with some aging machinery, Atherton said they’d rather take a proactive approach to the future of ST.

“It’s a tremendously successful class right now,” he said. “But you want to make decisions now to ensure that would be going forward,” Atherton said.

“With great self-effacing candor, I’d say we are being more reactive in the GS category. To suggest otherwise would be hard to explain.”

IMSA is even looking at the possibility of adding a third category to the mix, with Bennett confirming that LMP3 could find a home in Continental Tire Challenge.

If it materializes, it could result in the elimination of the Prototype Challenge class in the WeatherTech SportsCar Championship, which is only confirmed through the 2017 season.

Bennett said it’s important to find a place for LMP3 under the IMSA umbrella.

“I would hope there’s an opportunity that would make sense for this paddock,” he said. “I think it’s an important part to have, a level below our P class.”

As has been in the case in the WeatherTech Championship, Atherton said their ideal total car count for the series would be in the high-30s to low-40s.

The IMSA bosses stressed that decisions will not be made overnight and that they are seeking feedback from stakeholders on the best way to move forward.

“We for sure have a theory and had one for quite some time,” Bennett said. “But it would be wrong for us to make a decision in a vacuum.

“We’re trying to work through the system and not just throw something out there.”

Any potential changes for 2017 would likely come with some sort of grandfathering period for existing machinery, Bennett said.