Toyota’s promise that unlocked Rovanperä’s domination

Having lost to Hyundai in Finland last year, Tom Fowler and the technical team told themselves it couldn't happen again


For a car made on the world’s fastest rally roads, the Toyota GR Yaris Rally1 simply wasn’t fast enough last year. Watching Hyundai beat them at home on Rally Finland hurt. Tom Fowler and his team made themselves a promise: it wouldn’t happen again.

Kalle Rovanperä’s dominant performance at last week’s Rally Estonia would indicate the Jyväsykylä squad is on the money. And Fowler’s delivered on his promise. And now – with the Tartu winner’s trophy well and truly locked away – DirtFish can reveal why the engine upgrades that powered the 22-year-old to the win so nearly didn’t happen.

“Where we struggled last year,” Fowler said, “was engine performance and hybrid delivery – the combination of which we call the power unit. This was particularly against Hyundai. We were a bit mediocre and that really held us back.

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“The driver can put as much effort in as possible, I mean, you can have the best-handling car but if every time you accelerate out of a junction at full speed you lose half a second it’s demoralizing. And you then have to take so much more risk to try and get that back – and we really saw that’s what happened with Kalle last year, particularly in Finland.

“So we made a promise to ourselves that that wasn’t going to happen again, and the engineering team has pushed really, really hard in the last 12 months to deliver something for here.”

But what is it? What made the difference? What got Kalle out of those junctions quicker and gave him the tools to deliver total domination of the weekend?

Fowler: “The main part we’ve changed in the engine is actually the exhaust system, and the exhaust system’s obviously heavily linked to how the turbocharger is operating and the turbocharger is linked to airflow in general through the engine.

“We’ve been working a lot on the air path to make sure that the airflow into the car is working well with the body shape and the aerodynamics. Obviously internal, external flow is all linked.”


The location of the turbo has also been changed along with better optimization of the gear ratios. The impact of those changes was obvious from testing, but when it came to the homologation process, there were more than a few sleepless nights.

“Honestly speaking,” said Fowler, “a few months ago it was looking like we wouldn’t get everything done.

“With the situation we have in the world now, the delivery times on parts is so slow. To be able to do the design, order the parts, get them into the test car, prove them out for reliability, check that it’s really going to do what we think it’s going to do… at the moment, that process is slower than it was three years ago.

“So it’s difficult to bring updates and be really sure they’re what you want and reliable – and it definitely was a couple of months ago [when] the deadline from the FIA was coming nearer.


“The engineers and the team together really had to push hard to get this stuff here. I would say I’ve been particularly nervous because to bring such a big update, that’s so important, and to be rushing it through at the last minute never feels comfortable.

“Of course, we haven’t taken any unnecessary risk because we want to remain reliable, but for sure when you have so much going on in such a short timeframe you open the door to miss things and, hopefully, we haven’t done that.”

Estonia offered the strongest indication possible that nothing’s been missed.

The cake, however, sits ready to be iced in Jyväskylä a week on Sunday.