Action Express Racing topped the time charts in near-frigid opening day of testing at Daytona International Speedway, as TUDOR United SportsCar Championship teams prepare for the season-opening Rolex 24 at Daytona.

RESULTS: Testing 1
RESULTS: Testing 2

Christian Fittipaldi peddled the No. 5 Corvette DP to a quick lap of 1:38.630 in Friday morning’s 1-hour and 45-minute session.

It stood as the quickest time of the day, despite a 1:38.898 lap time recorded by the No. 90 Spirit of Daytona Corvette DP of Richard Westbrook in the afternoon.

Ambient temperatures dipped into the high 30s in the morning, with the high barely reaching 50 degrees Fahrenheit, which created difficult conditions for all teams.

“We managed to have a good practice today,” Fittipaldi said. “We applied everything that we learned in the sessions we had here prior to today, once in November and twice in December. So today was really good and the car felt pretty good.”

The Brazilian, who shared the wheel of the Coyote-chassied entry with Joao Barbosa and Sebastien Bourdais, led a Corvette DP 1-2-3, with the quickest non bow-tie being the No. 1 Extreme Speed Motorsports HPD ARX-03b in fourth.

The Ryan Dalziel, Scott Sharp and David Brabham-driven entry reeled off a 1:40.006, the quickest lap time seen for a P2 car thus far. However, it was still nearly 1.5 seconds adrift from the pace-setting DPs.

Five -time and defending race winners, Chip Ganassi Racing, completed the top-five overall with its No. 01 Riley-Ford of Scott Pruett, Memo Rojas, Jamie McMurray and Sage Karam.

CORE autosport-run machinery paced both the Prototype Challenge and GT Le Mans categories.

Colin Braun turned a best lap of 1:42.468 in his Oreca FLM09 in the two-hour and 30-minute afternoon session to go quickest on the day in PC.

The CORE-operated Porsche North America outfit, meanwhile ended up quickest in GTLM, thanks to Nick Tandy’s 1:45.564 in the No. 911 Porsche 911 RSR, which makes its debut on the Daytona high banks this weekend.

“One thing that probably does help us is that although this car is new in the U.S., it has raced before in Bahrain in the WEC in this particularly spec,” Tandy explained.

“We’re probably at a better point in our development process with this car than some of the other teams. It’s part of that reason why we’ve come out very competitive on the first day. But it’s very close.”

The two brand-new Corvette C7.Rs came within two-tenths of the factory Porsche on Friday, while the pair of SRT Motorsports Vipers were closely in tow, as well as the solo Aston Martin Vantage V8, which set the third quickest time in the morning.

GTD was led by Flying Lizard Motorsports in both morning and afternoon sessions, with Spencer Pumpelly’s 1:48.444 in the No. 45 Audi R8 LMS ending up as quickest of the day in the 27-car class.

No major incidents were reported during either session, with red flags predominately for debris only. Only the No. 32 GMG Racing Audi R8 LMS made contact with the tire barriers.

Four additional testing sessions are on tap for Saturday, beginning at 9 a.m. ET.