Ford drivers lead the way at Phillip Island
Pye was fastest in a drying first practice session, whilst Winterbottom topped the timesheets in a largely wet second outing.
Winterbottom had a moment that saw him spin into the gravel trap at turn two, before recovering to be fastest.
"Tricky conditions," Winterbottom said.
"On the first lap I really conserved, on the drying track and then the next lap I tried to push harder and started spinning at (turn) two and I went off backwards. It''s a bit hit and miss," said Winterbottom.
Despite the off and the difficult weather conditions, Winterbottom says he is happy thanks to the team finding a good set-up in the car ahead of the weekend''s racing.
"The car was good. We made a change between sessions. We''ve been chasing a direction on the car for a long time, and it that the first big progression forward we''ve made.
"If you have a quick car, you qualify well at the front. Get a good start, and you''re away from that pack.
"Just try to get to the front and clear out. That''s the safest thing," he said.
Pye is confident that he can continue the strong run of form he and his team are showing in the back half of the season, including a podium at the last round in New Zealand.
"The car overall was very strong," said Pye.
"I feel like we''ve rolled out (of the truck) pretty competitively this weekend.
Pye believes that the weather will play a part over the weekend, particularly due to the strong winds that sweep in off Bass Straight.
"We see here that the track dries so fast. If it''s windy tomorrow, it could rain and then within five laps the track is pretty dry. I''d probably put my money on it being dry, but you never know. We are in Victoria!"
Jason Bright was third, and the only driver in the top five to set his best time on the wet weather tire, with title fighters David Reynolds and Craig Lowndes fourth and fifth.
There were plenty of run-offs in the second session – particularly for Lowndes – as the drivers tested the limits and conditions.
The Holden Racing Team''s teammate Garth Tander managed the sixth fastest time, with Nissan''s Rick Kelly, Erebus'' Will Davison and Volvo''s Scott McLaughlin ensuring all manufacturers featured in the top 10.
Teams will have a quick 15-minute practice session tomorrow at the WD-40 Phillip Island SuperSprint before back-to-back qualifying at 12.45pm AEDT and two 60km races to follow tomorrow afternoon.