The latest incident of the valve train-related issue occurred in spectacular fashion in Sunday’s Darwin Triple Crown finale when Chaz Mostert’s engine expired with a handful of laps to run.
Forensic work on the issue started as soon as Mostert’s Supra arrived back in the garage after the race and was swiftly identified as the same issue that cost Ryan Wood the Jason Richards Trophy in New Zealand in April.
Andre Heimgartner suffered the same failure during the opening round in Sydney while valve-related reliability issues occurred during development work in 2025.
“From the initial analysis, it looks the same as what we had in Christchurch,” WTWGR team principal Carl Faux told Speedcafe.
“It’s not unknown, it’s a problem that we’re working on. We’ve got some bits in the works.
“From a hardware point of view, nothing has changed from the beginning of the year, so it’s a problem we’ve been managing. It’s a top end problem and it’s a known issue.
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“The solution to it is in the works. The good thing is, it’s not a new problem. We know what it is, and we just need to manage our way through this part of the year until we can get the parts made.
“The parts are already in manufacture. We have not found a new problem here, which I don’t want to say is satisfying, but absolutely there is some relief to it.”
With a solution well in the works, the challenge now is in its implementation.
That includes manufacturing parts, installing them in enough power plants to service the five Supras in the field and then having the updated engines undergo the required checks by Supercars in Queensland.
The entire process is further complicated by the mid-season run of long-haul races, with a staged rollout that Faux is adamant will be completed before the Bathurst 1000.
“It’s about getting the new parts through manufacture and then into the fleet of engines up and down the grid,” explained Faux.
“It’s not the work of a moment. One engine is easy to do, but it’s not one engine.
“If you’re going to risk mitigate, the first moment you can do it, you do it. And then you keep rolling it out as quickly as you can. Ideally you’d do it at once, but we don’t have that luxury.
“We’re in Darwin, so it’s four or five days until we get everyone back to Melbourne. And then we’ve got a week to get everything turned around to head to Townsville. And then after Townsville we go to Perth.
“So logistically, it’s a big challenge. And we are Melbourne-based, and everything we do has to go to Supercars up in Queensland, so we lose time with that as well.
“Logistics are the biggest problem with this, because the technical issue, we have the solution for.
“They will be done by Bathurst. I’ve got no issues with that. It’s just about how much quicker than that we can get it done with the logistical issues we’re facing.”
On the positive side, the Supra package has been competitive across the last two rounds – Tasmania and Darwin – which are both power sensitive.
That’s despite a known hole in the torque curve of the Toyota V8 compared to the more-established Ford and Chevrolet engines.
Faux, who has been heavily involved in the Toyota engine development, praised Supercars for its recent mapping work based on temperature studies, introduced before Tasmania.
“I’m really grateful to Supercars for what they did with the temperature correction,” said Faux.
“We didn’t know how that would affect our engine compared to the others, but we’ve been the coldest and the hottest events and it’s looked good.
“The way we achieved that is with the variable valve timing that we introduced to the engine and it allows Supercars to manipulate that into different ranges for different temperatures. That’s a positive.
“We still understand there’s sub-optimal torque in an area, which we’re working on.
“But always the first priority is reliability. Because we’ve lost a position in the pit lane because of what happened [on Sunday].”
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