Grand-Am's Rolex Series and Continental Tire Sports Car Challenge divisions begin their “regular seasons,” if you will, this weekend at Barber Motorsports Park. It's been two months since both opened at Daytona, and the nature of the 3.56-mile “roval” runs in complete contrast to Barber.

For starters, Barber is a notoriously difficult track to pass on. The traffic density won't be too bad in Rolex, with only nine Daytona Prototypes and 19 GT cars entered. But in the Continental Tire ranks, nearly 80 combined cars in GS and ST will populate the 2.3-mile, 17-turn road course! Picking places to make passes and staying on course will be key to success in either race.

One area that should be less controversial for the Rolex Series is Grand-Am reverting back to 2011 wave-by procedures for lapped cars. The “lucky dog” rule, which caused some friction and dispute among some class owners at Daytona, has been dropped, so the first car one lap down in class will not be able to get back on the lead lap. That should make the race somewhat easier to follow and avoid some extra confusion. Here are some of the other news and notes to watch for going in.

ROLEX SERIES

The bumper crop of entries that pushed Daytona's number to nearly 60 has been cut almost in half for Saturday's race, as the full-season cars begin their proper quest for the respective titles. Largely, the three presumptive title favorites are looking for a bounce-back after frustrating starts to the season at the Rolex 24.

For Telmex Chip Ganassi Racing with Felix Sabates and defending Barber winners Scott Pruett and Memo Rojas, sixth was the end result after 23rd hour gearbox issues at Daytona. Back with the traditional two hour and 45 minute race distance, and the first sprint race of its new third-gen Riley-BMW, the team seems primed to get back to victory contention.

“This will be an incredibly interesting DP championship,” Pruett said. “Our finish at Daytona hurt us, no question. We have a big deficit to overcome, but there are a lot of pieces in play this year with the new Corvette DPs and new Riley bodywork, plus our changeover to the BMW M3 engine later in the season. Nothing's really changed for us; our focus is winning races and the championship.”

The top Corvette DP squads from SunTrust Racing and GAINSCO/Bob Stallings Racing, however, have a bigger mountain to climb after ending last and second last (13th and 14th) at Daytona. SunTrust's was engine related in the first hour, while GAINSCO encountered myriad woes from the night onward. Both squads tested at the new New Orleans Motorsports Park in the interim, as they sort out their packages.

Daytona winners Michael Shank Racing resume with its usual pairing of Ozz Negri and John Pew, now absent the Justin Wilson/AJ Allmendinger dual threat, in its Riley Ford. Horsepower isn't necessarily as big an advantage at Barber, so the car's agility and balance might be more important than outright speed. It will have to be a weekend of mixed feelings for Shank, who seeks a 2-for-2 Rolex start but will see the IndyCar Series racing alongside, and his team not present on that grid, as well.

Starworks Motorsport, too, has its usual pairings established with Ryan Dalziel and Enzo Potolicchio sharing its new similar Riley Ford and Alex Popow and Lucas Luhr in the second one. The team won the series' last sprint race, last year's season finale in Mid-Ohio.

A trio of Corvettes – Action Express's two and the singular Spirit of Daytona entry – round out one of the series' smaller recent DP counts.

In GT, the podium sweeping Porsches figure to have a stronger fight on their hand. Magnus' pairing of Andy Lally and John Potter now seek their first sprint race win after its Daytona triumph, but will have to take down the Brumos duo of Leh Keen and Andrew Davis and now two TRG Porsches. Kevin Buckler's squad announced earlier in the week Jeroen Bleekemolen would pair Emilio di Guida in a second GT3 Cup, alongside the first entry driven by Spencer Pumpelly and Steve Bertheau.

Other potential class winners could include the Stevenson or Autohaus Camaros, the Dane Cameron/Wayne Nonnamaker Sahlen's Mazda, the SpeedSource Mazda, or defending race winners Turner Motorsport BMW. There's only a single Ferrari 458, down from five at the Rolex, for AIM Autosport Team FXDD and the Jeff Segal/Emil Assentato pairing. The two Audi R8s resume, with APR Motorsport in its home race and Oryx Racing with Steven Kane looking to show off his speed once more. Marsh Racing (Corvette) and Horton Autosport (Porsche) make their 2012 debuts, with Horton's Eric Foss and Patrick Lindsey aboard for John Horton's squad's series debut.

CONTINENTAL TIRE SPORTS CAR CHALLENGE

Attempting to parse down the CTSCC field is much easier said than done, and the hope for all participants is that the race doesn't become a version of bumper cars given the high car count and small track density.

Of note, Shelby Blackstock of Roush Performance will shift back to his Ford Mustang Boss 302R after consecutive weekends in his Andretti Autosport USF2000 open-wheel duties on the Mazda Road to Indy. The team itself looks for two wins in a row to start the year in the GS class with Billy Johnson and Jack Roush Jr.

As at Daytona, Starworks will also field four Mustangs. Some of the other GS multi-car squads seeking success at Barber include Fall Line Motorsports (three BMW M3 coupes), Multimatic Motorsports (two Aston Martin Vantages), Turner Motorsport (two BMW M3s) and CKS Autosport (two Camaro GS.Rs). Rum Bum Racing switches from BMW to a Porsche Carrera this race for drivers Nick Longhi and Matt Plumb.

In ST, APR Motorsport – which also fields an Audi S4 in GS – leads the field with five other Volkswagens, three Jettas and two GTIs. The three i-Moto MazdaSpeed 3s, two Kinetic Kia Fortes, quintet of Mazdas MX-5s from C.J. Wilson Racing (two) and Freedom Autosport (three), quartet of Compass360 Honda Civic SIs and Bimmerworld Racing BMW 328is should also be in contention. 

• The Rolex Series Porsche 250 airs on SPEED on a delay basis Saturday at 4 p.m. Eastern.

• The Continental Challenge race from Barber Motorsports Park will air on SPEED on April 8 at 12 p.m. ET