Daytona Beach, FL — Now that yesterday’s test day is in the books, full-on action for the HSR Classic Daytona presented by IMSA is on the schedule for today through Sunday.

Photo: Patrick Tremblay (HSR)

With the official schedule and entry list updated last week, Historic Sportscar Racing is now overseeing the largest running of the fifth event — with over 300 drivers in more than 180 entries from 15 countries.

It is the first running of the race with a reformatted and expanded Run Group structure – most notably the division of the original Group E into two distinct classes each featuring modern but retired prototypes and GT race cars from this century.

Photo: Patrick Tremblay (HSR)

Here’s a rundown of those groups.

• Group A (1962-1972): Featuring legendary and early FIA-era prototype and GT machines that raced in international and world championship competition, the group has attracted race cars such as the Lola T70 and T165, Ford GT40 and several Chevron B8 and B16 models. Production-based cars of the era include an AC Cobra, Shelby Daytona Coupe, Shelby GT350, BRE Datsun 240Z and a strong lineup of early Camaros, Corvettes and Porsche 911s. Two entries of note are a pair of 1955 Mercedes-Benz 300SL Gullwing Coupes from the Germany-based HK-Engineering team. Vintage Motorsport columnist Jochen Mass co-drives one of the classic Mercedes along with teammates Hans Kleissl and the sister car duo of Christian Jager and Guido Haarmann.

• Group B (1973-1982): Includes Porsche 935s and other Porsche 911-based models, BMW CSLs and some big-bore Camaros and Corvettes; also home to several ultra-quick and classic sports prototypes including a half-dozen Chevron B19, B26 and B36 models, a March 75 S and Toj SC204. Another highlight is the return of the big-block Classic Automotive 1979 Greenwood Corvette with French sports car driver Jim Pla.

• Group C (1983-1993): Entries this year include the Lowenbrau HR1 and an ex-Kremer/Leyton House Porsche 962, a Jaguar XJR-5, March 83G, Nissan NPT90 GTP and a quick GTP “Camel Lights” Porsche Fabcar.

• Group D (1994-2003): Includes a competitive mix of early Doran and Riley Daytona Prototypes and several big-bore Ford Mustang T/A, Oldsmobile Aurora, Saleen Mustang and Corvette C5R entries that will battle for production car honors with Porsche 944, 964 and 996 entries.

• Group E (2000-2018): Includes premier ALMS and Le Mans prototypes not eligible to race at Daytona in their prime.

• Group F (2000-2018): Revamped to showcase modern Prototype and GT race cars.

• Group G (HSR Cars): Formerly competing as Group F, the new Group G division is home to HSR classes not represented in the other groups, offering a mix of primarily production cars from six different decades of competition, including many of the same teams and race cars that compete in HSR’s Vintage GT and Historic GT groups and the HSR Classic RS Cup and HSR Global GT series.