Interest is growing within the Pirelli World Challenge paddock for the inaugural California 8 Hours, with multiple teams on the verge of confirming entries for Intercontinental GT Challenge’s first trip to the U.S.

The Oct. 13-15 race, to be held at Mazda Raceway Laguna Seca, will mark the penultimate round of the SRO Motorsports Group-organized championship, which encompasses races on four different continents.

With local teams tabbed to make up the majority of entries for each race, a number of leading PWC GT outfits, including K-PAX Racing, Magnus Racing and RealTime Racing, are targeting to be on the grid.

SRO boss Stephane Ratel said he expects more than 25 cars for the race, with PWC officials estimating in excess of 30 entries, although a provisional entry list has yet to be released.

For defending PWC GT champions K-PAX, which took part in last year’s IGTC season-ending Sepang 12 Hours, an entry in the eight-hour enduro has been in “serious” discussions, according to program manager Darren Law.

“We’re seriously considering it, but we’re still evaluating everything,” Law told Sportscar365. “But from a cost standpoint, an entry standpoint… Who’s coming? Are teams from Europe coming?”

Nearly a dozen cars have already been announced for the event, which will be open to GT3 and GT4-spec machinery, as well as GT Cup and Invitational classes, similar to the makeup of February’s season-opening Liqui-Moly Bathurst 12 Hour.

PWC stalwarts GMG Racing has already revealed plans to field up to three Porsches, with ANSA Motorsports, Racers Edge Motorsports and TRG also confirming multiple entries each for the GT4 class.

Australian squad MARC Cars, meanwhile, is set to take part in the Invitational class with two of its purpose-built V8 Supercar-like machines, including a Mazda3 V8.

Law indicated that a certain level of support from McLaren would help them commit with at least one car, which would run for overall honors in the GT3 Pro class.

“This is a long event,” he said. “Is there some support from a manufacturer and what’s it going to cost to run it? It’s a big step for us financially. If we can make it happen, we will.”

Fellow GT squad RealTime Racing, meanwhile, could also be on the grid in Monterey, with the Peter Cunningham-owned squad understood to be planning an entry on behalf of Acura.

While it would mark the Acura NSX GT3’s IGTC debut, Cunningham indicated that a final decision would have to come from the manufacturer.

“There’s been a lot of thoughts to do that kind of race,” Cunningham told Sportscar365. “It’s not really part of the [PWC] championship, so I don’t know if we’ll be able to. It would certainly be of interest.”

Magnus Racing is also looking to commit to the race, potentially with factory support from Audi, which currently leads the IGTC points standings following its victory in last month’s Total 24 Hours of Spa.

The John Potter-owned team is currently in discussions with the German manufacturer for a potential two-car effort, with one entry to likely feature an all-factory driver lineup, similar to Audi’s efforts in previous IGTC rounds this season.

According to Head of Audi Sport customer racing Chris Reinke, a works-supported effort for Monterey, as well as the season finale in Sepang in December is likely.

“For sure we will try to integrate local teams for the two remaining races of the Intercontinental GT Challenge,” Reinke told Sportscar365.

It’s also understood Porsche, which sits third in the championship, is also preparing for at least one all-factory car, potentially utilizing machinery from Wright Motorsports.

Porsche factory driver Laurens Vanthoor is the defending IGTC drivers’ champion and is coming off a fourth place finish in a Team75 Bernhard-entered car at Spa, with the German manufacturer already committing to the entire championship.

While the interest level has been high from some PWC teams, a number of others have ruled out entries for the race, including Cadillac Racing and GAINSCO/Bob Stallings Racing.

Absolute Racing, which had been tipped to operate Bentley’s factory entries, is also unlikely to enter the event according to team director Ingo Matter, who indicated the cost to ship its endurance equipment from Asia would be more expensive than a team from Europe.

However, Bentley Motorsport Director Brian Gush, who attended last weekend’s PWC race at Utah, said they have still have yet to decide on whether the British manufacturer will commit to the race.

Bentley moved into second in the IGTC championship thanks to M-Sport’s runner-up finish at Spa, which has prompted questions whether it could complete the season, potentially with the Malcom Wilson-led operation.

Other PWC teams, such as Black Swan Racing, Always Evolving/AIM Autosport and Flying Lizard Motorsports are also eyeing entries, but for the Pro-Am class.