Jamie Whincup says Triple Eight's current output of new parts for its Commodores is as good as he's witnessed with the team.
The factory Holden outfit developed the new-for-2018 ZB, and started the campaign strongly with five wins in the first eight races.
An eight-race winless run between Phillip Island and Hidden Valley is now a distant memory, with Triple Eight having won seven of the last eight.
Five one-two finishes includes a sweep of the podium at Sandown, as Shane van Gisbergen has moved into the championship lead.
Firmly out of a patch in which Triple Eight's qualifying form was hit-and-miss, Whincup says the team's development is driving that run.
"We’ve got a real fat rule book these days," Whincup said.
"There’s not much you can do underneath but there is still some opportunity for our engineers to develop new parts and make the car faster, to bring a faster car to the circuit.
"I can’t think of another time we’ve thrown more parts, new parts, at the cars than the last three months.
"We’ve come forward leaps and bounds as far as mechanical engineering goes underneath, which has allowed us to showcase how good the aero is at the same time.
"Every track’s got its different elements and we try to make sure that we’re strong in the areas that each circuit needs.
"But the CNC machines back at work haven’t stopped for the last three months and it’s showing that we’re moving in the right direction."
Whincup is wary of drawing comparisons with other Triple Eight cars he's driven since joining the squad in 2006.
The seven-time champion now, though, feels the team is 'showcasing the quality' of the new-generation Holden package it developed.
"We’ve had some great cars over the years," he said.
"Certainly, compared to the rest of the field it was extremely quick [at Sandown].
"There’s been a lot going on behind the scenes, especially in the last three months.
"The ZB is a good thing, we just haven’t showcased the quality of the ZB and the development we’ve been doing up until recently.
"It’s a credit to everyone for the hard work that’s gone down."
Asked by Supercars.com what the Triple Eight cars were doing well at Sandown, Whincup pointed to the way they handled the circuit's kerbs, especially onto the long straights.
"I think they were good over the bumps, that was the good thing," he said.
"We’ve come here before and the thing’s bucking around and trying to spit us off in the wall.
"But the big gain for us was just the kerb control and being able to get onto those straights good just by riding the bumps well."
Triple Eight had a rough run at Bathurst last year, but are heavy favourites for this year's race following their domination at Sandown.