Updated Toyota engine passes 500km test at The Bend

Walkinshaw TWG, Toyota's homologation team in Supercars, is optimistic that its latest 'B-spec' engine will resolve the reliability issues that have plagued the Japanese manufacturer's maiden season. The engine, developed with UK-based Swindon Powertrains, has completed a 520-kilometer endurance test at The Bend circuit in South Australia without significant problems.

This test is a crucial step ahead of the Bathurst 1000, where engine reliability is paramount. Chaz Mostert and Ryan Wood shared driving duties in the Supra during the test, with Supercars officials, including engine chief Craig Hasted, present to monitor progress.

"We're really happy to have ticked off 520km with no issues," said Walkinshaw TWG team principal Carl Faux to Speedcafe. "We also did 250km on Monday at the ride day, which is a terrible duty cycle for the engine, and something we've not been able to do for a while."

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Faux added that they made good progress with fuel mapping alongside Supercars on Friday. However, he remains cautious about declaring Toyota's troubles over. Walkinshaw and Swindon had already implemented a fix for valvetrain issues after a failure in testing last year, but other problems emerged once racing began.

"From an engineering point of view, all of the numbers say that we've made a significant step forward in this area," Faux explained. "But we did thousands of kilometres in testing [ahead of the season] and when we got to go racing, other issues were highlighted. So am I 100 percent confident? No one in their right mind would ever say they're 100 percent confident. You can never be that. Am I happy that we've made a significant step in the right direction by reducing load on the valvetrain? Yes, I am."

The new specification engine underwent a preliminary run on Hasted's official Supercars dyno before being installed in the Supra. It will need to return to Brisbane for final sign-off before its competition debut at the upcoming Ipswich Super440. Faux hopes to have two updated engines—one for Walkinshaw TWG and one for customer Brad Jones Racing—in action at Ipswich.

If all goes to plan, that will be followed by a full rollout across the five Supras in time for the Enduro Cup opener at The Bend. Even with the update, Faux admits scheduled mid-event engine changes may occur to minimize failure risk at Bathurst 1000. "We'll see how many engines we have available at the time," he said. "Obviously, we've done a few precautionary [engine changes] this year because of things that we've seen. We may have to do that again."