Sahlen was fastest on the second day of Daytona 24 Hours testing on Saturday, as Dane Cameron's morning best proved the day's benchmark.
Cameron set a 1m42.101s lap in the opening session, the first of four during the day.
That put his GT graduate team's Riley-BMW 0.3 seconds clear of the two Ganassi cars in the session, and proved unbeatable for the rest of the day.
Friday pacesetter Michael Shank Racing was quickest in the two afternoon sessions. Michael Valiante led practice two with a 1m42.160s in MSR's #6 Riley-Ford, before AJ Allmendinger lapped in 1m42.296s in the next session. Ganassi and Sahlen were MSR's main opponents.
In night practice it was Starworks that led the way, with Sebastien Bourdais lapping in 1m42.644s in the #2 car to edge out Sahlen.
The Corvette contingent did not feature in the top three in any of the four sessions' final results, prompting murmurs of sandbagging from rivals.
Porsche again led the way in the GT class, with Patrick Long quickest in the Park Place car.
The test concliudes with two more sessions on Sunday.
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