Jamie Whincup and Chaz Mostert have admitted to struggling on Friday at the Century Batteries Ipswich SuperSprint despite both making the top 10.

Mostert was third fastest in Practice 2, meaning he safely earned a bye to the second part of tomorrow’s Armor All Qualifying session, while Whincup will join him there having ended up five spots further back.

Whincup was nevertheless downbeat about his showing, contrasting it to an encouraging test day at Queensland Raceway last week for the Red Bull Holden Racing Team.

“All in all it was a disappointing day,” he declared.

“We felt like we had a good test day last week and moved the car forward but today felt like the car was completely different.

“Unfortunately, after the two practice sessions it seems like we have taken a step back.

“We will keep looking at the data and see where we can improve because at the moment, we are in struggle street.”

Whincup’s sentiments echo those of Shell V-Power Racing’s Fabian Coulthard, who also tested at Queensland Raceway last week.

Coulthard finished a position ahead of the seven-time champion but was still extremely frustrated with his Mustang to the point that he felt like a rookie.

Mostert was two tenths slower than Coulthard’s pace-setting team-mate, Scott McLaughlin, and second fastest of those in the Tickford Racing stable, but still expressed concern at the set-up of the #55 Supercheap Auto Mustang.

The Campbellfield-based Tickford tests at Winton, but Mostert suggested that track conditions could have played a part in spoiling set-ups.

“It’s been a bit of a tough day for us, 55,” he lamented.

“I probably expected to roll out a little bit stronger or get the car feel under me a little bit stronger, but we chucked the toolbox at it over the last two sessions, so probably have to go to the truck again and see if there’s another toolbox in there and then probably chuck the toolbox at it again.

“It could just be the track. It degrades every year we come, but for me the grip level out there, I’m just not feeling it through my car.

“Obviously we’re trying some different things, we’re trying to bridge a gap to these guys (DJR Team Penske) too. For me, we just need to chase a little bit more.”

Meanwhile, Whincup’s team-mate Shane van Gisbergen had a more inherent problem when his Practice 1 program was disrupted by a sensor problem in the #97 ZB Commodore.

The New Zealander finished the day fifth on the timesheets in Practice 2 but he too was not happy with the feel of his car.

“We began the day with a sensor issue which was a shame, but we didn’t lose too much time,” recounted van Gisbergen.

“The crew did have to take the gearbox out to replace the sensor. It’s a small thing but in fact it’s quite a big change within the car.

“In the second practice, we were okay with the last run as we ended in fifth. It’s obviously good to be in the second part of qualifying tomorrow.

“There’s another practice session tomorrow where there are a few things to work on, as despite the car being relatively fast it didn’t feel great.

“It’s a good start to the weekend so we are hoping to improve from there.”

The Virgin Australia Supercars Championship field returns to the track for Practice 3 tomorrow from 1035 local time/AEST, followed by Armor All Qualifying at 1325.