Super GT News

Subaru says its decision to replace the almost 20-year-old ECU on its SUPER GT challenger is akin to “upgrading from Windows XP to Windows 10”.

After winning last year’s GT300 title for the first time, the R&D Sport-run Subaru outfit has been busy upgrading its BRZ for the 2022 campaign, showing off its revised machine last week during a shakedown event at Fuji Speedway.

Chief among the changes are a revised front bodywork section, designed to increase straight line performance, and a new ECU for the car’s two-litre, four-cylinder turbo engine.

The BRZ uses the same base EJ20 engine that Subaru once deployed in its World Rally cars, with team manager Masahiro Ozawa also having been part of that project as an engineer.

Subaru driver Takuto Iguchi, who was in charge of shaking down the BRZ at Fuji, noted that the change in ECU has left the car facing a shortfall in straight line speed which may take time to alleviate.

“We are starting from scratch, so to be honest we haven’t been able to set it up correctly yet and we haven’t reached our previous engine performance,” admitted Iguchi.

“I think we have to set it up during testing to reach at least the same level as last year, otherwise we won’t be competitive.”

But Ozawa said he was convinced the time to replace the ECU had come, as it had been using the previous unit for so long.

“Up to now we had continued using the same ECU as we had during the WRC era, since around 2003,” he said. “It’s like upgrading from Windows XP to Windows 10, so to speak.

“If the underlying ECU is old, it won’t be as accurate [as newer ones]. So, we decided to change to a new type and try and extract everything from the engine with higher accuracy.”

SUBARU BRZ Shakedown
Photographer:Motorsport.com / Japan

Besides the engine, Ozawa said that Subaru had been focusing on being able to maintain its current straight line performance even with anticipated Balance of Performance changes in the wake of its 2021 title triumph.

He also said the team was aiming to maintain its supremacy in terms of handling via changes to the suspension.

“We think that winning the championship means we will be given a BoP that reduces our power to weight ratio,” he said. “Therefore, we have been developing in such a way that even if our weight increases, we can keep our top speed by having better aerodynamics.

“As for the chassis, we were able to show a strong performance in the second half of the season, but after the final race we put the car on the [shaker] rig, we evaluated the suspension and some weaknesses were revealed.

“We found things we can improve further, so we are aiming to increase the accuracy of the set-up and make a car that can corner even faster.”

Iguchi gave his approval of these changes, adding: “Already last year we reached a high level with the chassis and aero, and the parts we’ve changed have raised the standard even further, so I hope that can make up for whatever performance we lose with the BoP.”