The Bathurst 1000 co-drivers were given half an hour of running as part of the Sandown SuperSprint this afternoon.
The session is the only official running for co-drivers before practice for the Great Race kicks off in early October.
Triple Eight duo Whincup and Garth Tander were consistently at the top across the co-driver session, although initially it was Tander that led the way with a 1m08.548s.
Walkinshaw Andretti United's Fabian Coulthard briefly jumped the pair late in the session with a 1m08.519s.
However a green tyre run right at the flag saw Whincup fire to the top with a 1m08.230s.
That time was roughly two tenths quicker than primary driver Broc Feeney went in the #88 Holden in the earlier session today.
Tander was also able to improve on his final run to move back ahead of Coulthard, the gap to Whincup around two tenths.
Tony D'Alberto was the best-placed Ford with the fourth fastest time in the #11 Dick Johnson Racing entry, while James Moffat led the way for Tickford in the Cam Waters car.
Alex Davison (#17 DJR Ford) was sixth fastest while Zak Best went slightly quicker than primary driver Thomas Randle in the #55 Tickford Ford as he was left seventh in the order.
Dale Wood (#8 BJR Holden), Jack Perkins (#9 Erebus Holden) and Jordan Boys (#96 BJR Holden) completed the Top 10.
Craig Lowndes, meanwhile, was 20th fastest in his cameo with Brad Jones Racing, all but matching Jack Smith's time from the earlier session.
