Pye explains bizarre practice collision with Whincup

Saturday morning's action at The Bend Motorsport Park began in high drama, with both Red Bull Ampol Racing Camaros colliding during a Safety Car procedure test.

In a heart-stopping moment, Jamie Whincup hit the rear of teammate Scott Pye during a Safety Car test at the beginning of Practice 5 at the AirTouch 500 at The Bend.

In a designated 'slow zone' during the test, Whincup was seemingly caught napping and hit Pye, with the latter forced into the garage with heavy damage to the left rear.

Whincup pitted and quickly returned to the session, with Pye sidelined for the remainder of the session as the team undertook a transaxle change on the #1.

Speaking on the broadcast, Pye admitted he was initially caught out by the procedure, but suggested Whincup simply missed his marker. Later, Whincup admitted fault.

" They're definitely tricky. I even learned then that I asked the question to Andrew [Edwards, engineer], but there's no countdown for the release either," Pye said.

"And when I asked the question, he said, 'release.' So I never went. And then, even out of Turn 12, I didn't go and cars are trying to pass me. And the rule is you can't pass.

"Cars are going unnecessarily slowly, which you can normally, but in this they're saying not to. So, I learned the lesson there that you just can't use the radio under the Safety Car at the moment, because if they call release at just any point, you might lose that.

"And then with the slow zone, I think Jamie's maybe just missed the board there on the exit to Turn 3, just being relatively close to me.

"Obviously I'm pushing up to that line to make sure I maximise my decel[eration] and not lose any time. So I braked real hard and he's just been caught out and hit me in the rear.

"So, a fair bit of damage. But yeah, we're learning and it's complicated system, but yeah, it is what it is."

Officials have introduced a series of Safety Car rule changes for the weekend, with tests also taking place on Friday. Notably, drivers slow down to 80km/h and pit lane is closed, before a 'slow zone' is left in place.

James Moffat put Tickford Racing's Castrol Ford on top of the time sheets ahead of Team 18 veteran Lee Holdsworth, with the top five completed by the three wildcard entries.

Drivers return for final practice at 12:00pm local/12:30pm AEST, followed by Boost Mobile Qualifying at 3:05pm local/3:35pm AEST.

Saturday's action concludes with the Boost Mobile Top Ten Shootout at 4:50pm local/5:20pm AEST.