Toyota locked out the top five positions in the delayed 2020 curtain-raiser earlier this month, as TOM’S pair Nick Cassidy and Ryo Hirakawa breezed to a comfortable win.
Honda put up a strong fight in qualifying, with the #8 ARTA NSX-GT setting the pace in Q1 and bagging a spot on the front row in Q2. But in the race its challenge wilted, as the Team Kunimitsu car of Yamamoto and Tadasuke Makino was its top finisher in sixth.
Speaking to Motorsport.com, Yamamoto said he was surprised at how much extra time the Toyotas were able to find between Q1 and Q2, describing their step as “like witchcraft”.
The 2018 SUPER GT champion also said that the 10km/h top speed gulf between the GR Supra and the new front-engined NSX-GT was unlikely to be down to aerodynamics alone.
“From the Sepang test onwards, I knew the Supras were focussing a lot on long runs, and that they were running well, so I thought they might show their strength in the first race,” Yamamoto reflected. “But finally, they were even stronger than I had expected.
“The engine seems to be in a different dimension. The aerodynamics and the shape of the body are different, so it could be due to drag, but all the same it’s hard to believe that a 10km/h difference is all down to the body.
“After the season opener, when I looked back, it seemed in practice and Q1 the NSX-GT had the edge over its rivals, but then [Toyota] suddenly improved its laptimes in Q2.
“Given that conditions in Q1 and Q2 were mostly the same, I don’t know how the times changed so suddenly for cars from a particular manufacturer. It seemed like witchcraft. It was if they [Toyota] had flicked a switch or something.
#100 RAYBRIG NSX-GT、#36 au TOM’S GR Supra
Photo by: Masahide Kamio
“Did they hide their speed until Q2, or did they, seeing the speed of the NSX-GT up until Q1, try something different? I’m not sure, but that step up in speed was difficult to think about.
“We take the fact that the Supras have shown this sort of strength seriously, and we want to make sure we have the ability to challenge them in the next race.”
Yamamoto took the start in the #100 NSX-GT, holding second position for many laps in the early stages as he held up the faster #36 TOM’S Supra of Sacha Fenestraz.
After conceding the position to Fenestraz, Yamamoto handed over to new teammate Makino for the second stint, but the second safety car period left Makino vulnerable to the faster Supras behind and he was eventually demoted to sixth.
Makino said post-race he was suffering with tyre pick-up, something that Yamamoto believes is an inherent characteristic of both the current and previous-generation NSX-GT.
“When the tyres were new, I felt the grip of the tyres allowed the car to maintain its balance and fighting power,” Yamamoto explained. “However, as the tyres started to wear and as the grip decreased lap after lap, that nervous behaviour began to appear [more and more].
“There was quite a bit of pick-up, but this issue hasn’t changed compared to the previous NSX-GT. Even if the position of the engine has changed, the same thing is happening. Unless something fundamental somewhere in development is reviewed, I have a feeling we will be stuck with this problem forever.
“As well as the engine position changing, there are more common suspension parts [this year as a result of the Class One rules], so what had been said to be the cause of the problem [before] has been eliminated [as a possibility].
“Because this year the differences with the other manufacturers are less [because of the new rules], I think there must be another reason.
Naoki Yamamoto（#100 RAYBRIG NSX-GT）
Photo by: Masahide Kamio
“When the temperature drops or downforce increases because of the conditions, or indeed when running alone, we can demonstrate 100 percent of the strength of our car, but in a race situation where other elements come into play, it’s easy to get pick-up.”
Yamamoto said he was buoyed by the pace shown by the NSX-GT in qualifying, as ARTA driver Nirei Fukuzumi ended up with a new track record courtesy of his Q1 effort.
But he admits that Honda needs to create a car that can excel in a wider window of conditions to be able to threaten Toyota when the series returns to Fuji for the second round of the season on August 8-9.
“If the performance of the car is fundamentally poor, I think we could not fight for the top positions in qualifying,” said Yamamoto. “If we can show the performance that we did in practice or Q1, I think we have the strength to beat any car.
“But in terms of making a car strong in all conditions, our understanding of the car is still low and we haven’t been able to find the answers.
“The time until the second race is short, but in that time we need to improve our weaknesses and we need to make a car that is also strong in the race.”
#100 RAYBRIG NSX-GT
Photo by: Masahide Kamio