Out of the four classes in next year’s Tudor United SportsCar Championship, the GT Daytona category is set to see the biggest influx of new machinery.

That includes Porsche’s new 911 GT America, which is likely to make up more than half of the field in the production-based Pro-Am class.

According to Porsche Motorsport North America President Jens Walther, who recently spoke with Sportscar365, around 20 teams have expressed interest in running the 991-based Cup car, which will be adapted to IMSA specifications.

“We approached the 2014 season from two sides. Should we use our GT3 R, which is the FIA GT3 car, or should we try to accommodate the Cup car and build it to the regulations of the new series?” Walther said.

“We sat together with IMSA and it appeared due to the different classes, the [GTD] class is going to be significantly slower than what we see this year, due to the GT Le Mans cars, so we decided to go for the Cup car.”

Walther said there is roughly only a 5 to 7 percent difference in components between the 911 GT3 Cup car, which currently completes exclusively in Porsche Supercup, and the new 911 GT America.

The biggest change comes with the flat-six powerplant, which has been enlarged from 3.8 to 4.0 liters, as well as the GTD class-wide spec rear wing.

More importantly, the GTD class will see a freeze in development, aimed to help reduce operating costs for teams. The 911 GT America retails for $269,000, which is expected to be by far the least expensive option on the grid.

“What we’ve seen in the past is that customers in GRAND-AM were able to take a standard Cup car and modify it almost to a RSR spec,” Walther said. “That led to a point where many customers couldn’t afford racing the car anymore because it was so expensive.

“IMSA and ourselves together wanted to bring this down. The idea was to have a car, based on the Cup car, ready to race, for under $300,000, which allows good racing and affordable pricing.

“Through the regulations, IMSA has informed us that they will make sure that you can’t change anything more with the cars. So all of the cars, not only the Porsches, will be homologated to a certain specification.”

Porsche will build up to 15 cars in the 911 GT America configuration, although Walther said they will only initially sell them to customers already committed to the full Tudor USCC season. The existing 911 GT3 Cup cars currently seen in GRAND-AM and in the ALMS will not be legal in USCC next year.

A number of teams have either placed orders for new cars or have expressed interest, including Park Place Motorsports, Muehlner Motorsport, NGT Motorsport, Alex Job Racing, Magnus Racing, Dempsey Racing and Paul Miller Racing, among others.

“Every year, all of the manufacturers get a lot of interest because people are shopping around,” Walther said. “We believe that between 10-12, and maybe 15 Porsches, would be a very good field for us. We hope that there are other manufacturers in well in GTD because we like competition.

“We know it’s going to be a challenge to get these cars on the same level. With the performance level from GT Le Mans at the upper end, it will mean the cars will be significantly slower than this year but with IMSA we have the right people working on that and I’m very confident we’ll find the right balance of performance.”

Deliveries of the new GTD contenders are expected to begin early next month, with a handful of cars likely to be at the first official pre-season tests in Sebring and Daytona later that month.

On the GT Le Mans front, Walther confirmed the new factory 911 RSRs will not be at the November test, due to the proximity of the FIA World Endurance Championship race in Bahrain, but will rather likely take part in private testing in Florida in December.