Preparations continue for what could be the largest gathering of GT3 machinery in the world next March, when SRO hosts a round of its new intercontinental GT challenge at Circuit of The Americas alongside the 2016 Pirelli World Challenge season-opener.

The jam-packed weekend will include all six PWC classes in action, as well as a six-hour endurance race, run by the organizers of the popular Blancpain GT Series, as part of the first collaborative effort between SRO and PWC.

According to PWC Competition Director Marcus Haselgrove, the two organizations made progress with planning for the event during PWC’s recent trip to Misano for the Blancpain Sprint Series round in Italy.

“We’re in discussions on how we do things,” Haselgrove told Sportscar365. “Everything from how we share garages to time slots on the schedule to who’s eligible from both sides of both events.

“I think for a sports car fan, it’s probably going to be around the biggest collection of current GT3 cars racing [in the world]. We could possibly surpass car count for Spa [24].”

Haselgrove, who along with interim WC Vision CEO Greg Gill, met with SRO representatives, including CEO Stephane Ratel, to help shape the March 4-6 event, which will mark SRO’s return to North America in a decade.

With the aim of attracting a 30-car grid for the Blancpain Endurance Series-style race, Haselgrove said they’re pooling their resources together to attract a mix of teams and GT3 manufacturers from Europe and the U.S.

“That’s the beauty of working together,” he said. “We have our U.S. database and they already have their customers committed. We have a very open forum with Stephane and his team.

“You’re all basically racing the same class of cars at the end of the day. We also have customers that want to enter their event, so it’s fine.”

More than 60 GT3 cars are expected for the weekend, between the PWC and SRO races, making it one of the most attractive offering for fans, although Haselgrove admits the early March date doesn’t make it a perfect fit to pack the grandstands.

“The question, personally, is that we need to get more fans to COTA,” he said. “We certainly had weather against us this year. Our event reminded me of my days living in Finland mapping rally cars in the snow.

“But for the quality of the venue, we need to get more people in the stands and get more people coming through the gates.

“It’s an amazing spectacle, but nothing’s worse than going to a track with all these great drivers and manufacturers competing but not many fans.”

Talks for future collaborative efforts between the two organizers continue, with news on that front expected next month at SEMA.

“These talks continue, both at the manufacturer level and with SRO and PWC,” Haselgrove said. “The key thing to me is that people racing the same products are all talking. That’s what the manufacturers ultimately want.”