The Kiwi struggled through today's action at Hidden Valley, qualifying a relatively poor 11th and battling his way to eighth in the race.
Even then that eighth place only came courtesy of a gamble on tyre strategy, van Gisbergen taking on four new tyres 14 laps from home before putting in a charging drive to make up some late ground.
Having been overheard complaining about straight-line speed over the radio during the race, van Gisbergen confirmed afterwards that T8 will fit a new V8 unit to his car this evening.
"It’s been a bit frustrating so we’re doing a motor change on my thing tonight,” said the Kiwi.
“We’re lacking a lot of power. I came out of the corner, had a big run on Chaz [Mostert], went to the inside wall to stop the draft and saw him come flying back past me.
“Hopefully a new motor helps. [I need to] tune up some of my stuff as well. Jamie’s driving a bit different and I can’t get my head around it yet, so I’ll work hard tonight."
Today's result has left van Gisbergen fifth in the standings, 311 points – more than a whole round – behind leader Scott McLaughlin.