The Pirelli World Challenge Championships continues its 25th anniversary 2014 season at Sonoma Raceway, returning to the challenging and scenic 12-turn, 2.38 mile road course. The series' GT, GT-A and GTS classes, will compete in two races, one on Saturday and one on Sunday.

Among the large field that will compete at Sonoma, there are a number of GT/GT-A entries (cars identified by the black windshield banner) to watch. Also of note, the top class in the series features a number of teams running full FIA GT3-spec cars for 2014.

Cadillac Racing's two aces, two-time defending GT Driver's Champion Johnny O'Connell and veteran teammate Andy Pilgrim, pilot the team's CTS-Vs. In 2014, Cadillac looks to three-peat in GT Manufacturers', Team and Drivers' (O'Connell) Championships. O'Connell won at Long Beach, as well as both races at Detroit.

Toronto's R. Ferri Motorsport runs a pair of Ferrari 458 GT3 Italias with talented drivers Anthony Lazzaro and Nick Mancuso piloting the cars. Lazzaro won the Round 3 race at Barber Motorsports Park.

GMG Racing's James Sofronas, in the Audi R8 Ultra, came close to knocking O'Connell off of the top perch in 2013 and will look to do so in 2014. Sofronas' talented teammate Andrew Palmer, in another of the GMG Audis, won at Barber in Round 4.

K-PAX Racing remains a stalwart in the series, but with a huge change. The team has switched over from Volvos to run two McLaren 12C GT3 with drivers Alex Figge and Robert Thorne. It's the debut for the McLaren 12C GT3 in the US, and Figge, who has won five races over the last couple of seasons, and Thorne will look to put the McLaren in the victory circle.

Another highlight of the 2014 season is the entry of Dyson Racing in Pirelli World Challenge. The team brings the Bentley Continental GT3 to the series with Butch Leitzinger behind the wheel of the No. 08 car.

Mike Skeen, pilots the No. 2 Hawk Performance CRP Racing Audi R8 LMS Ultra. Skeen won both races at Road America. EFFORT Racing enters a Porsche 911 GT3 R for Tim Bergmeister in GT, and for Michael Mills in GT-A. 

In GTS, at times any of six different manufacturers competing had a shot to win a race in 2013. With a highly talented list of drivers piloting a projected 20-plus cars at Sonoma, expect that number to stay that high, if not grow. GTS cars are identified by the grey windshield banners.

Defending and three-time Drivers' Champion Lawson Aschenbach runs alongside teammate Tony Gaples in the Blackdog Speedshop Chevrolet Camaros. Aschenbach started the season off strong with a win at St. Petersburg, but of late his Camaro has been the victim of mechanical gremlins. He looks to bounce back at Sonoma.

The two drivers Aschenbach beat out in 2013, Jack Baldwin and Mark Wilkins, are also back for an encore. Baldwin once again pilots one of the GTSport Racing with Goldcrest's Porsche Cayman Ss - as will Buz McCall - while Wilkins again races for the Kinetic Motorsports Kia Optima team alongside Nic Jonsson. Jonsson won back-to-back races at Road America, while Wilkins won Round 3 at Barber, and Baldwin won Round 4 at Barber. 

Jack Roush Jr. leads the Ford Mustang Boss 302 contingent, in his ROUSH Performance Mustang entry. Of the more than a half dozen Mustangs in GTS, others to watch include Picture Cars East/Rehagen Racing's Dean Martin and Capaldi Racing's Brad Adams.

Follow the 2014 Pirelli World Challenge Championships all season long at Watch the races from Sonoma on NBC Sports Network, Saturday, Aug. 30 at 10 a.m. Pacific.