The Harvey Norman Supergirls have completed back-to-back test days at Winton Motor Raceway and can now only look forward to Mount Panorama when they will next tackle the Ford Falcon FG X.
Swiss Simona De Silvestro, 27, and local Dunlop Series racer Renee Gracie, 20, put two allocated test days to good use and learned as much as possible about the Prodrive-prepared race car they will take to the Supercheap Auto Bathurst 1000.
Prodrive team boss Tim Edwards was pleased with the testing - 175 laps over two days, a total of 525km of running, with pit stop practice and driver change practice thrown in the mix.
"To be honest I think everybody was pleasantly surprised at how well both of them adapted to the car," Edwards told v8supercars.com.au.
"Now - particularly Simona - can drive the car like it's second nature."
International IndyCar import De Silvestro - who has only raced open wheelers - experienced driver changes in a V8 Supercar for the first time, which put her out of her comfort zone.
"As you can imagine for Simona jumping in and out of the car doing driver changes having no one there to do her belts up for her like IndyCar was quite an alien thing!" Edwards said.
"But that went all really well and they're already down to quite an impressive time that's well below the refueling time. "We ticked every box we wanted to and the speed they've both shown - and Simona's ability to adapt to this type of car has come
leaps and bounds just in these two days."
Edwards was positive about Gracie's performance as well.
"Obviously [the FG X] is a different beast for even Renee to be driving, and her speed in the cars was very impressive," he said.
"Renee's times were significantly faster than her qualifying times in the Dunlop Series race earlier this year, so I think even she was a little bit shocked at the speed she found. All in all the test couldn't have gone better."
While there seemed to be some trepidation from the girls earlier in the week, Edwards was confident both ladies were ready to tackle Mount Panorama.
"Simona, having never driven this type of car in her career, there was a huge amount of unknown before driving the car," he said. "I think neither of them underestimate the task of the 1000 but they're a lot more comfortable and relaxed with what lies ahead having now had these two days of testing."
De Silvestro believes she improved further today.
"I feel I am finally starting to get to grips with the technique required to extract speed in the key areas," she said.
"I'm also getting better at knowing where to place the car and the driving position is starting to become more familiar. Driver changes are new to me and the learning curve was quite steep but we're getting there."
Gracie revealed the two were looking for slightly different things from the car but had managed a compromise that works for both and should translate at Mount Panorama.
"Simona and I have been recording similar times but have a slightly different feel, so today we tried to find a good compromise and we seem to be heading in the right direction," Gracie said.
"The pit stop practice was valuable and we started off pretty slowly and awkwardly then got much better over time ... further practice will help us to reduce that time even more. A massive two days of learning."
The next time the pair hit a race track will be at Mount Panorama on Thursday with three 45-minute practice sessions scheduled. Edwards said improving the girls' confidence will be the key.
"Bathurst is quite unique ... to carry the speed you have to across the top of the mountain relies on a reasonable amount of confidence in the car and your own ability," he said.
"There are so many blind corners and crests there's not much margin for error."
Twenty-seven V8 Supercars will line-up at Mount Panorama this year, with Drew and Aaren Russell also entering a wild card for the Great Race.