The Prototype, Prototype Challenge, and GT Daytona classes of the TUDOR United SportsCar Championship will take to the track on Detroit's Belle Isle this weekend for the Chevrolet Sports Car Classic, combining for a 25-car grid. 

Eight of the 25 are from the Prototype class. Two each from Action Express Racing and Mazda Motorsports (rather than SpeedSource; for branding purposes), the No. 10 Wayne Taylor Racing car (last year's winners), the No. 60 Michael Shank Racing entry, No. 90 VisitFlorida.com Racing entry, and the No. 01 Chip Ganassi Racing with Felix Sabates car of Joey Hand and Scott Pruett. Also, Starworks Motorsport will have a Prototype entry, but it will not be a Daytona Prototype - as is shown on the entry list. The DeltaWing was scheduled to race in Detroit but has opted not to. 

The Prototype Challenge class is set to make its debut on the 14-turn, 2.3 mile temporary city/street circuit of Belle Isle. One fewer PC car is entered than in the Prototype class at seven. Three gaps are open in the PC driver lineup as the weekend nears: Performance Tech Motorsports has a TBA spot empty alongside James French while Bar1 Motorsports has both of its driver spots TBA for their No. 16 ORECA FLM09 Chevrolet-powered spec car of the class. 

The GT Daytona field is the largest of the three with 10 entries set to take to the track, although both the Dodge Viper GT3-R of Riley Motorsports and Audi R8 LMS of Flying Lizard Motorsports have been dropped after competing in Monterey. After withdrawing from the last round at Mazda Raceway Laguna Seca (balance of performance concerns), the Wright Motorsports Porsche 911 GT America is set to return. 

The GT Le Mans (GTLM) field is absent from Detroit as a test day for the 24 Hours of Le Mans is Sunday - the day after the United SportsCar race in Detroit. They will race next at the 6 Hours of The Glen on June 28. 

Click here for the full entry list of the Chevrolet Sports Car Classic.

Be sure to follow the brand-new Twitter account of all SportsCar coverage on VAVEL, @VAVELSportsCar, for live tweeting and photos from the track this weekend in Detroit. 

Aaron Durant is the editor of the VAVEL USA Racing section. Follow him on Twitter at @DoubleA291.