Longhurst lifted the covers off his Steve Richards Motorsport-prepared Type 991 machine today, revealing backing from his Gold Coast marine maintenance precinct, The Boat Works.
Hay was hired for Longhurst's Bathurst outing after splitting with Supercars squad Lucas Dumbrell Motorsport in August.
The pair last worked together when Hay was in his first year with Stone Brothers Racing in 2000, narrowly missing out on a Bathurst victory that season.
“I didn't think I'd see Tony back racing at this level again,” Hay told Speedcafe.com.
“It's good because he's not an 18 year-old who is trying to make a name for himself. He'll do a good job.
“Realistically a top 10 on Sunday is do-able. He'll just sneak up on it.”
Longhurst was stirred into coming out of retirement and back into a quick competition car after guiding his 1994 Australian Manufacturers' Championship-winning BMW to victory at the Silverstone Classic meeting in August.
“The BMW was restored so well, everything except for the sequential gearbox, it felt just like it was when I raced it,” said Longhurst.
“Actually it had been 22 years since I drove it but it really felt like six months.
“The Porsche this weekend will be a whole new experience, but I cannot wait to get some more miles under my belt.
“I have driven a lot of different varied things in the last few months and it has all been great.”
Longhurst says the three-race Bathurst Carrera Cup format is crucial preparation for a possible tilt at the Bathurst 12 Hour next year.
“Nothing has been finalised yet but this will be decent preparation,” he added.
VIDEO: Longhurst on his Carrera Cup entry