The Pirelli World Challenge is poised for significant growth in 2015, with the GT and GTS classes set for separate races and both categories likely to see increased grids.

In the first “Silly Season” update for 2015, Sportscar365 takes a look at the confirmed, likely and possible entries for the GT/GT-A and GT Cup classes next year.

GT/GT-A:

Confirmed Entries (23 cars):

Cadillac Racing — The factory Pratt & Miller squad will return with an all-new FIA GT3-spec Cadillac ATS-V.R for Andy Pilgrim and three-time and defending series champion Johnny O’Connell. The Detroit-based team will be seeking its fourth straight manufacturers’ title in 2015. (2 cars)

K-PAX Racing — After numerous seasons with Colorado-based 3R Racing, the Jim Haughey-owned K-PAX squad have joined forces with Flying Lizard Motorsports, as the operations partner for its pair of brand-new McLaren 650S GT3 cars next year. Drivers have yet to be announced. (2 cars)

Dyson Racing Team Bentley — After a mid-year debut in 2014, the Poughkeepsie, N.Y.-based team will field two Bentley Continental GT3s for the entire season, with Butch Leitzinger and Chris Dyson the expected pilots for the championship-seeking effort. (2 cars)

EFFORT Racing — Following a breakout 2014 season, the Texas-based squad will return with its pair of Porsche 911 GT3-Rs, one each for GT and GT-A. Multi-race winner Ryan Dalziel is expected to lead the driving force for the majority of the season, with the team’s Am-class driver still to-be-announced. (2 cars)

DragonSpeed — Elton Julian’s outfit switches from Ferrari to Mercedes-Benz for 2015, with a trio of SLS AMG GT3s set to do battle in GT-A. Henrik Hedman will be joined by IMSA regulars Eric Lux and Frankie Montecalvo in the three gull-winged beasts. (3 cars)

Turner Motorsport — The former series champions make their full-season return with a pair of BMW Z4 GT3s. While drivers have yet to be announced, it’s understood Bill Ziegler will pilot one of the Bimmers, possibly to be joined by a high-profile driver at the wheel of the second Z4. (2 cars)

RealTime Racing — Expected to be the only non FIA GT3-homologated car on the GT grid, the two RealTime Acura TLX GTs will be driven by Peter Cunningham and Ryan Eversley, who moves from full-time Continental Tire SportsCar Challenge competition for the new factory ride. (2 cars)

CRP Racing — One Audi R8 LMS ultra is expected for the Hawk Performance-backed operation, but it remains to be seen whether 2014 GT runner-up Mike Skeen will return as driver. Alex Lloyd also ran an older Corvette in selected 2014 races and could be in the frame. (1 car)

Black Swan Racing — Tim Pappas’ Mercedes-Benz SLS AMG GT3 will return with a relatively unchanged program from 2014, which will see the owner/driver compete in the GT-A division again. (1 car)

Scuderia Corsa — After dipping its toes into the series last year, the Giacomo Mattioli-owned team is set for a two-car full-season program with Ferrari 458 Italia GT3s in 2015 for a pair of to-be-announced drivers. A third Prancing Horse could be seen at select rounds for Mike Hedlund. (2-3 cars)

TRG-AMR — Kevin Buckler’s California-based operation will make the step up to full-season GT competition with Christina Nielsen signed to drive an Aston Martin V12 Vantage GT3. (1 car)

NGT Motorsport — The IMSA stalwarts will expand into PWC next year with an expected two-car Porsche 911 GT3-R effort. Drivers have yet to be announced. (2 cars)

LG Motorsports — Lou Gigliotti’s team is planning a multi-car comeback that includes one Aston Martin Vantage V12 GT3 for a to-be-determined driver. (1 car)

Likely/Possible Entries (11-18 cars):

GMG Racing — The California-based team are expected to return with its multi-car Audi R8 LMS ultra squad, with up to three of the German sports cars between GT and GT-A, including one Pro class entry for Sofronas. (3 cars likely)

R. Ferri Motorsports — After having been one of the standout teams of 2014, the Canadian squad is expected to return with up to two Ferrari 458 Italia GT3s. (1-2 cars likely)

Cameron Racing — Steve Cameron’s team is expected to run an Audi R8 LMS ultra for Drew Regitz, who is set to move up from GTS into GT-A. (1 car likely)

Lone Star Racing — No word has come on whether Dan Knox will return with his customer Dodge Viper SRT GT3-R for a second season, but assuming he does, it would likely be the lone full-season Viper on the grid. (1 car likely)

JCR Motorsports — Wisconsin-based Jeff Courtney has run most of the schedule over the last couple years and should maintain a similar length program, if not a full season. (1 car likely)

Reiter Engineering — At least one Reiter Engineering Lamborghini Gallardo Extenso R-EX could be possible for the full season, with a second added for selected races. Marcelo Hahn ran a full season in 2014 with Tomas Enge, Albert von Thurn und Taxis and Andy Lee all running selected races. (1-2 cars possible)

M1 Racing — Walt Bowlin ran a partial season the second half of last year but no word has come from the driver or team as to whether the GT-A class driver would return. (1 car possible)

Taggart Autosport — Jim Taggart is expected to run a similar partial season schedule in his Porsche 911 GT3-R for at least two or three race weekends, with potentially more to come. (1 car likely)

Andretti Autosport — Latest reports indicate the veteran open-wheel squad could enter up to three Nissan GT-R NISMO GT3s next year, as part of a larger-than-expected foray into PWC. (3 cars possible)

Vita4One Racing — Michael Bartels’ team has frequently discussed the possibility of running North American races, but is yet to pull the trigger with his BMW Z4 GT3. Car was entered for St. Petersburg last year before being withdrawn; could run early season races. (1 car possible)

Conquest Racing — Eric Bachelart’s team has been out of full-time competition since running a Morgan Nissan LMP2 car in the 2012 American Le Mans Series, but could join PWC having mentioned the possibility earlier this offseason. (1 car possible)

Darren Manning Team — Former IndyCar driver Darren Manning has explored the potential of a PWC program based in Indianapolis, but offered no further details in terms of car choice or season length. (1 car possible)

Estimated Car Count: 23-41 entries

GT CUP:

Confirmed Entries (10 cars):

NGT Motorsport — No drivers have been named yet for the Ramez Wahab team, which like several others plans to have cars in multiple PWC classes. (2 cars)

Kelly Moss Motorsports — The Porsche GT3 USA stalwarts shift over to GT Cup, with 2014 series champion Colin Thompson the first confirmed driver in a proposed three-car effort. (3 cars)

TruSpeed — Team with past PWC experience is expected to run a multi-car effort in GT Cup, although without any details announced at this point. (2 cars)

Phoenix American Motorsports — Preston Calvert will run both an Ford Mustang Boss 302S in GTS and a GT Cup Porsche next year, making him one of the busier drivers in the championship. (1 car)

DragonSpeed — The DragonSpeed effort also features teenaged rookie Victor Gomez Jr. in a Porsche Cup car. (1 car)

Motorsports Development Group — Mitch Landry has been with MDG for several seasons in GTS and is expected to continue with the team for his move into GT Cup next year. (1 car)

Likely/Possible Entries (1-2 cars):

GMG Racing — The James Sofronas-owned team is looking to expand into the GT Cup class next year with one Porsche entry for an undisclosed driver. (1 car likely)

TBA — One high-profile sports car squad is finalizing an effort for a GT Cup effort. An announcement is expected in the coming weeks. (1 car likely)

Estimated Car Count: 10-12 full-season entries

(Tony DiZinno contributed to this report)