GPS data clocked the Kiwi at an eye-watering 300.5 km/h at the end of Conrod Straight yesterday afternoon.
It marks the first time a Supercar has officially hit the magic 300 km/h mark on the longest straight on the calendar.
The cars are also using the soft Dunlop tyre at Bathurst for the first time, which helps drive off Forrest's Elbow, which leads onto Conrod Straight.
According to Triple Eight team manager Mark Dutton, van Gisbergen's record breaking speed was also helped by favourable wind direction and a tow from another car.
"It was all depending on the wind. The wind was not helping but not hurting yesterday," said Dutton.
"Then Shane got a big tow, then you get more speed with less drag on the car. You wouldn’t do that same speed in fresh air by yourself, but it was still pretty cool."
Dutton added that there was no concerted effort to hit 300, rather it was an organic outcome from the conditions.
"While it is a cool thing, we don’t focus on that, we just focus on lap times," he said.
"It’s a cool little thing to say, ‘hey, we did this’, but you don’t let it distract you."
This may be the first official indication that a Supercar has hit 300 km/h at Bathurst, however there have been rumours in the past.
In 2005 the Perkins Racing team claimed a top speed of 302.4 km/h based on its own data – however the claims were met with widespread scepticism elsewhere in the paddock.
A change to the drop gear ratio in 2015 renewed hopes the magic 300 could be hit, however it never eventuated.
Supercars did look at running a longer drop gear at Bathurst this year, but ultimately decided against the change.
That likely would have contributed to van Gisbergen's record speed as well, given the ratio in use is still good for 300 km/h, and would improve drive off Forrest's Elbow.
Interestingly, Triple Eight was one of the team's in favour of the longer ratio for Bathurst on the basis that it would be kinder on the motors, although sitting on the limiter hasn't been an issue so far this weekend.
"It was only to make sure the category wasn’t doing any damage," Dutton said of the lobbying for the longer gear.
"We don’t honestly care, it’s all about not sitting on the limiter for everyone, because that gives the engine a hard life.
"It’s not just about getting through Bathurst, these days the engines have to last a lot longer than they did many moons ago, to save everyone in pit lane dollars."