As the 25th anniversary season of the Pirelli World Challenge draws to a close, with Sonoma Raceway playing host to the penultimate event of the season this weekend, teams and manufacturers are already gearing up for what could be an even bigger championship next year.

The 2014 season has been all about GT3, with the arrival of the globally recognized platform boosting car count and leading to the creation of the new GT-A sub-category. With more than two-dozen teams now regularly competing in the top class, it’s also led to split GT/GTS races for 2015 and the exploration of an endurance round.

“I think World Challenge is on the cusp of a major transition into being a [top series],” Cadillac Racing technical program manager David Caldwell told Sportscar365. “The sprint race format itself is so attractive. I know you don’t get the driver change aspect but the driver gets to own it.”

While having been a staple in the WC Vision-run series for the last four years, Cadillac has seen a significant transformation in its competition, with the pair of CTS.V-Rs, built to legacy regulations, now facing Audi R8 LMS Ultras, Porsche 911 GT3 Rs, McLaren MP4-12Cs, Ferrari 458 Italia GT3s, Lamborghini Gallardo FL2s as well as a Mercedes-Benz SLS AMG GT3 and the Bentley Continental GT3, which debuted mid-season.

Cars such as the Audi and Mercedes were introduced into the championship last year, but with a number of aero modifications, which led to Balance of Performance and drivability issues.

“World Challenge learned very quickly, literally halfway through last year, that it didn’t go so well,” Caldwell said. “Instead, they looked at the FIA-homologated car, in its pure form, to come over here and race. I think that was a really good call.”

It’s led to the arrival of Dyson Racing, a longtime stalwart of ALMS and GRAND-AM competition, to join the championship with a factory-backed Bentley Continental GT3 for Butch Leitzinger. The team will expand to a two-car operation at Sonoma with the addition of Guy Smith to the lineup.

“If you look at the competition and diversity of the cars, with first through tenth being separated by a couple of seconds, it’s impressive,” Chris Dyson said. “I think it’s credit to the whole GT3 platform.

“I think it also goes to show you the interest in this series. These are legitimate companies that are coming here, putting a lot of OEM money into the series. They’re definitely doing the right things.”

There’s also a healthy grid of privateer entries, including a GT-A class Mercedes for Black Swan Racing, another former ALMS championship-winning team that made the switch last year.

“Because it’s a sprint series, you’re not putting incredible amount of hours on the cars, so the maintenance is affordable, although the cars are expensive,” said Jeremy Dale, team advisor to Black Swan Racing and team owner Tim Pappas.

“It’s so different from everything else that’s going on in North America, sports car racing-wise. They’re not trying to be an endurance series; there is one of those. World Challenge is trying to do something different.”

Dale, who also fields a Porsche 911 GT3 Cup car in the IMSA-sanctioned Porsche GT3 Cup Challenge, is exploring a potential expansion of JDX Racing into World Challenge for next year.

“I’m impressed with the series,” he said. “I like the growth path they’re on and that they’ve embraced the GT3 cars.”

DragonSpeed team owner Elton Julian, meanwhile, also sees a increase in car count to come, with his Florida-based team in talks with several Ferrari Challenge drivers about a step up to the series next year with 458 Italia GT3 machinery to join its existing entry for Henrik Hedman.

“I think the GT/GTS split is the biggest thing for us,” Julian said. “They were right not to do it at the beginning of the year because the car count was low. I think now there’s maybe five, six, seven cars that could be coming in the next 10 months.”

While the addition of GT-A, a class reserved for gentlemen drivers, has helped grow the field, Cadillac’s Caldwell thinks it could be taken one step further with a three sub-class format, similar to what’s currently seen in the Blancpain Endurance Series.

“I’d like them to look at a Pro, Am and Gentleman Cup, all in GT,” Caldwell said. “It works in other series and it’s reasonable what you look is behind the different teams and cars.

“It’s not unreasonable to say that it might create a spot for the factory that’s behind a couple of cars. Then it also supports some of the bigger teams that have six or eight of the same cars and with some up-and-coming drivers. You also have guys here that absolutely love it, but they have no internal expectations to be running at that level.

“I think the three [sub classes] might create a spot for everyone to be here and resolve some conflicts on what the expectations are.”

While talk of a potential endurance round for 2015 has gone quiet, World Challenge newcomer Chris Dyson has remained upbeat about the future of the championship.

“The actual paddock vibe is very friendly and helpful,” he said. “It’s still very serious and competitive but it’s nice to be here. You feel a really good sense of camaraderie. In a lot of ways, it feels like a paddock should.

“I think between the sprint race format they’ve got, the venues they’ve got and maybe with some endurance racing coming online [in the future], it’s an interesting place to be right now.”