Something as seemingly innocuous as gravel and dust are poised to ruin the fun of Supercars drivers this weekend on a newly resurfaced Winton Motor Raceway.

Pre-event talk about super-fast lap times came true in Friday’s practice with Holden’s Tim Slade setting a new lap record in the first of two one-hour sessions at the 3km circuit.

Slade’s time of one minute and 19.2435 seconds eclipsed Fabian Coulthard’s 2014 mark of 1:19.6538.

All up, five drivers went under Coulthard’s time in the opening session.

Faster times were expected from the second session as the track cooled but, instead, gravel – kicked up from a kerb on turn eight – ended up hampering drivers’ efforts.

Several drivers had to slow down through the hazard to keep their cars on the track, leaving Slade’s time untouched as the quickest of the day.

Holden’s Shane Van Gisbergen, who posted the day’s second-fastest time with a 1:19.3311 in the second session, said the dirt on the track had played a role in the day’s times.

“No one else did any better because there was just so much stuff around the track,” Van Gisbergen said.

“All the test days they’ve had with continuous running have been pretty bad. You could just see people going off and dragging it all back on.

“Unfortunately, it makes it one line which makes it harder to pass. Hopefully, it stays good and we can have some good racing.”

Slade said he was unable to improve on his earlier time in the second session due to the debris.

The Brad Jones Racing driver said it would be a particular issue in Saturday afternoon’s qualifying session.

“It could just be luck of the draw, someone gets a lap in and then that person might drag a heap of gravel on the track and, unfortunately for the next bloke behind, it ruins your lap,” he said.

“I don’t know if they can do anything about it … they need to try and do something because you could just luck out tomorrow in qualifying.”