This is an exclusive post-event Supercars.com column by championship-winning Race Engineer Scott Sinclair. Sinclair will preview and debrief each round of the 2026 Repco Supercars Championship from his own perspective.
Chaz Mostert took centre stage on the Gold Coast and cemented his reputation as a big-time Finals performer.
He won the weekend overall, had exceptional speed in both the wet and the dry, dropped back to help a mate, and, above all, announced he’s well and truly in the hunt for a second straight championship.
Team orders: yes or no?
If I were the team manager at Walkinshaw TWG Racing, I wouldn’t have thought twice about slowing Chaz Mostert down to help Ryan Wood progress to the next round of the Finals. It was a no-brainer for mine, especially as they were running third and fourth at the time, meaning they could manage it without other cars getting involved.
As it turned out, that position swap wasn’t enough, with the late-race dramas pushing Anton De Pasquale above Wood. Naturally, the question then becomes: was it worth it?
Based on Mostert’s pace before he was asked to drop back, he’d have caught Brodie Kostecki with around nine laps to go. Given the pace differential, I suspect he would’ve gotten past. But by then he’d only have caught Broc Feeney with a few laps remaining, probably without enough pace left to take the win.
The decision likely cost Mostert second place, and with it, the chance to finish ahead of Kostecki in the Finals standings. The flow-on effect is that he now starts Sandown only 12 points clear of the top four cut-off instead of 30.
What sets the remaining seven drivers apart
For the seven drivers remaining, their championship hopes depend on nailing both races at Sandown. To do that, you need two things: speed, and the ability to convert that speed into race results. That’s stating the obvious, but separating those two attributes in this season’s data gives us some insight into what each driver needs to progress.
In this instance, we define 'speed' as race pace within 0.3% of the fastest car on track — generally what's needed to win. The conversion rate is how often you convert a fast car into the result that speed deserved. The seven drivers fit into three distinct buckets:
Bucket 1: Those who have speed but don’t convert as often as others. Matt Payne, Brodie Kostecki and Broc Feeney sit in this bucket. They’ve had race-winning speed in over 70% of the races this year. But they’ve converted it around 60% of the time, a lower conversion rate than all but Mostert.
Bucket 2: Those who convert when they have the speed, but don’t have the speed as often. Will Brown, Anton De Pasquale and Cam Waters sit in this bucket. When they have the speed, they convert it around 75% of the time, the best of the bunch. They just don’t have it often enough, in less than 40% of races.
Bucket 3: Those who have lacked both speed and the ability to convert. Chaz Mostert sits in this bucket, with a fast car in only 38% of the races and a conversion rate of 25%. But, and it’s an important ‘but’, these numbers cover Mostert’s entire season, which saw him finish the regular season 8th in the championship. He certainly wasn’t in this bucket on the Gold Coast. Nor was he during last year’s Finals Series, where he had great speed and converted in all but one race.
So what’s my point? For Payne, Kostecki and Feeney at Sandown, converting the speed they’ve shown all year will be enough to get them to the Grand Final. Brown, De Pasquale and Waters need to be faster. And Mostert just needs more of what he did on the Gold Coast.
Engineering errors
We again saw two significant calculation issues on the weekend. This time, a lack of fuel cost Jarrod Hughes a top five finish in his first solo race weekend, and cost Cooper Murray a season-best sprint result on debut with PremiAir Racing.
That’s three straight events where the calculator (or lack of it) has had a significant impact on the results.
It’s worth noting there have been no rule changes that would’ve contributed to this recent run of mistakes. We’re seeing errors in simple calculations that teams have otherwise done successfully for years.
As AI infiltrates the teams, and custom software that automates any number of tasks can be written in hours, staying focused on the basics seems to have become a challenge.
‘AI slop’ is the term used to criticise AI output that takes shortcuts or makes assumptions to reach a solution. At the moment, we’re seeing a plague of ‘Data Engineer Slop’.
A round too late for Heimgartner
Andre Heimgartner missed the Finals after finishing 11th for the second year in a row, but his season deserves a call-out, having largely slid under the radar. Like Mostert and Wood, Heimgartner and his Brad Jones Racing teammates have taken on the giant task of developing the Toyota Supra over the last 12 months.
Of the 24 drivers in the championship, only Will Brown’s race results have improved more across the season. Heimgartner was fifth in the Enduro Cup and backed it up with two fifth-place finishes on the Gold Coast. That moved him into 10th in the championship, unfortunately one round too late for the Finals.
The challenge now is starting next season the way he’s finishing this one to ensure he makes the Finals cut in 2027.
Scott Sinclair is one of the most respected voices in pit lane, famously engineering James Courtney to the 2010 championship with Dick Johnson Racing. Sinclair also spent stints at the Holden Racing Team and Kelly Racing, spent time on the Supercars Commission, and recently joined Supercars as a data analyst.
The views in this article do not necessarily express the opinions of Supercars, teams or drivers.
