Yesterday was August 23rd (Sun.), and on this day Aug. 24th (Mon.), just one day after the running of the 2026 AUTOBACS SUPER GT Round 5 race, the “SUZUKA 300km RACE” a total of 17 cars, including three GT500 class cars and 14 GT300 class cars gathered at Suzuka Circuit in Mie Prefecture to participate in the 2027 Official Tire Test. Following the 1st tire development test held on Aug. 3rd after the Round 4 race at Fuji, this time the 2nd test was conducted.
◎Test Run: 9:00～12:00 Weather: clear skies / Track surface: dry
From the 2027 season it has been decided that the official tire supplier for the SUPER GT GT500 class will be Bridgestone and for the GT300 class it will be DUNLOP. For this reason, the season’s 2nd Tire Development Tests were held on the day after the Round 5 race, The “SUZUKA GT 300km RACE” at Suzuka Circuit. The previous development tests held the day after the Round 4 race were run under cloudy skies from start to finish with the air temperature rather low, but this time the tests at Suzuka, although it was comparatively cool in the morning, soon there were sunny skies overhead and the temperature became hot, as it had been for the Round 5 race.
The schedule for this day was to hold just one test session from 9:00 in the morning to 12:00 noon. When the course was opened, three GT500 lass cars and 14 GT300 class cars took to the track, but 10 minutes into the session the No. 87 OPEN HOUSE Lamborghini GT3 (Kohta Kawaai / Natsu Sakaguchi) crashed at the 130R Corner. Because of the need to repair the tire barrier there was a 28-minute stoppage. Also, from about 2 hours and 25 minutes into the session, Takuto Iguchi driving the No.61 SUBARU BRZ R&D SPORT (Takuto Iguchi / Hideki Yamauchi / Shunji Okumoto) suffered from transmission trouble coming out of the NISSIN Break Hairpin and came to a stop. This caused the Red Flag to be shown for the second time.
In the GT500 class, three cars, the TGR-D No. 90 GR Supra, the HRC No. 99 HRC Prelude-GT and the NISMO No. 230 Z NISMO GT500 joined the session as they had at FUJI. Driving the No. 90 car were Sho Tsuboi and Nirei Fukuzumi, and the No. 99 car was driven by Tadasuke Makino and Kakunoshin Ohta. Also, the No. 230 Z NISMO GT500 was driven by Katsumasa Chiyo and Mitsunori Takaboshi. The GT500 class had cars running menus of short and long runs. All of the cars ran best times in the 1’46 sec. range. The 1’46.019 sec. lap run by the No. 90 GR Supra was the top time of the day.
Among the 14 GT300 class cars, the six cars including the No. 2 HYPER WATER INGING GR86 GT (Yuui Tsutsumi / Kazuhisa Urabe), the No. 60 Syntium LMcorsa LC500 GT (Hiroki Yoshimoto / Shunsuke Kohno). The No. 62 HELM MOTORSPORTS GT-R (Yuya Hiraki / Reiji Hiraki), the No. 65 LEON PYRAMID AMG (Naoya Gamou / Togo Suganami), the No. 88 VENTENY Lamborghini GT3 (Takashi Kogure / Daniil Kvyat), and the No. 666 seven x seven PORSCHE GT3R EVO (Sven Müller / Taichi Watarai) all ran tests for 2027 as dictated by DUNLOP.
Also participating were the No. 60 LC500 and No. 65 AMG, and the three No. 666 PORSCHE cars ran development tests as they had at the 1st tests at FUJI, while the other cars, including the No. 11 GAINER TANAX Z (Ryuichiro Tomita / Kazuki Oki), the No. 20 SHADE RACING GR86 GT (Katsuyuki Hiranaka / Eijiro Shimizu), the No. 22 R’Qs AMG GT3 (Masaki Kano / Hisashi Wada / Masaki Jyonai / Yuma Shoji), the No. 25 HOPPY Schatz GR Supra GT (Takamitsu Matsui / Ryota Horachi), the No. 31 apr LC500h GT (Kazuto Kotaka / Miki Koyama / Charlie Wurz), and the No. 61 BRZ and the No. 87 Lamborghini participated.
During the 3 hours, many of the cars conducted serious tests such as running a full 61 laps, and the top time in the GT300 class was the 1’57.170 lap run by the No. 30 apr GR86 GT (Hiroaki Nagai / Hibiki Taira / Manabu Orido). The second fastest time was that of the No. 2 GR86 while running development tests and third fastest time went to the No. 60 LC500.
○ Sho Tsuboi (No. 90 TOYOTA GR Supra)
“I felt the difference between the development tires and the one-make tires, but since we don’t know what the actual structure is or what compounds are being used, it felt like we were able to drive on them with no preconceptions. In a sense it was like we were driving the tests blind. I had a feeling that something was different compared to the test at Fuji, and the tires felt unlike the ones we had been using previously. That said, since it is a Bridgestone tire after all, the feel is completely different, yet I don’t get the impression that there has been a truly dramatic change. However, being able to discuss what the aim in restricting things to one tire brand was between the three car makers and the tire maker, and what kind of tires would make it more exciting for the spectators to watch, these are things that feel like they have just begun to deal with. As a first step I felt that they were very good tires, but we want to know what they are aiming for from here going forward.”
○Mitsunori Takaboshi (No. 230 Nissan Z NISMO GT500)
“I can’t make an unconditional comparison with what we used in the Round 5 qualifying at Suzuka. but I got the impression that the performance hasn’t dropped in comparison with the tires we are using now. I got the same feeling as with the tires we used in the Fuji (tests), but I feel that there is a difference in the characteristics compared to the tires we are using in races now. And since they have a different feeling from the tires until now, there is a need to get used to them, and I feel that adjustments have to be made in the way we use them and the direction of the car’s setup. But I feel it is amazing that although they have a different feeling the times we are running don’t change much. At this stage, I feel a big difference between the hard, medium and soft compounds, but in a race, we have to choose one type and then it doesn’t make any difference what the compound is. So, it is difficult because of the fact that the difference may be too big or small.
○Tadasuke Makino (No. 99 Honda HRC PRELUDE-GT)
“As it was with the tests at Fuji, I honestly don’t feel much a difference with the tires we used at Fuji, so I am just running the same as usual. Of course, the opinions of the other (car) makers may be different, but for us we don’t feel much difference, so we are able to run without much feeling that something is strange. Even looking at the lap times, I don’t get the feeling that performance has gone down much. On the contrary. I get the feeling that the times could go down somewhat, but then there is also the influence of running with the GT300 cars, and that also makes it difficult during races. When we did long runs at Fuji the pace was quite good, so I thought that might even be a problem. As one of the items that might make the races more interesting, I think it might be good if the tire performance is better.”
Sho Fukuzaki Bridgestone Corporation Engineer
“Basically, the development is going well. Having done tests twice, last time at Fuji and this time at Suzuka, although in the development of the soft, medium and hard compounds the same issues that came out at Fuji were also coming out at Suzuka, since we are narrowing down the issues, we want to continue to narrow down the specs until the final round of the season at Motegi so we can arrive at specs to go into next year with. We want to continue the development diligently until then.”
○Togo Suganami (No. 65 LEON PYRAMID AMG)
Regarding the level of grip, I felt that it is not inferior to the current competition compound. In terms of times as well, since we are getting times in the middle of the 1’57 sec. range, the times are on a good level compared to the times at the day before yesterday’s (Round 5) Qualifying. The impression is that the grip is very good. Of course, since the character of the tires is different from the tires we are used to using, and adjustments need to be made in things like the car’s balance, we are still able to run the same way as usual, which makes it fun to drive with now. We have now prepared three compounds, a soft, medium and hard, if we can get tires that are clearly good in each of them, I believe it will be a strategy that will give interesting results.”
○Yuya Motojima (No.88 VENTENY Lamborghini GT3)
“I was surprised at how easy the tires are to drive on. First of all, they warm up very quickly, and the peak grip was better than during the Qualifying. Also, in long runs as well, since I got times that would have put me in 2nd or 3rd place in the race of Round 5, I am really surprised. Also, the tires are very easy to handle, and in terms of sliding it is mild and easy to grasp. They were completely different from what I expected. I did long runs using both the soft and medium specs and I found that the soft compound warmed up after about two corners. And when I kept going for about 15 laps the performance didn’t drop at all. With the medium compound the front felt a bit hard, but I got a good time from the very first lap. So, I think it is a tire that anyone will find easy to use.”
○Yuui Tsutsumi (No. 2 HYPER WATER INGING GR86 GT)
“Although it is a one-make tire, the grip isn’t really inferior compared to the GT300 tires we race with, and even in these hot temperatures the times of the soft compound didn’t drop much, and it still had enough speed to be able to compete on this course, so being surprised was my first impression. The handling was also good. I ran on all three specs, the soft, medium and hard, and with the soft compound, despite the fact that we expected cooler temperatures, I got good times from the very first laps. As for abrasion, I believe we will have to see about that in the future. Also, with the medium and hard compounds I felt that I was getting the good balance I expected. I think that is amazing, isn’t it? So, I got a very positive impression.”
○Yuya Hiraki (No. 62 HELM MOTORSPORTS GT-R)
“Regarding the NISSAN GT-R NISMO GT3 we are using, the tire size is different from what we are used to, so we used the same tires front and rear. The impression at Fuji wasn’t bad for any of us, and we got good information about how to run on them. So, we went out with good expectations, but to tell the truth the results weren’t good. We usually use harder tires, but when we are using tires with the same structure and compounds as the other teams, the peak (performance) was weak, and the long-run performance was inferior. Since this is the condition we were in, it appears that the people at DUNLOP felt there are things that need to be improved going forward.”
Naoya Kubo Assistant Manager Motorsports Dept. Sumitomo Rubber Industries, Ltd
“Because we are in a position where we don’t really have much choice, since the Round 4 tests we have initially been thinking about to some degree making one-make tires in a package that won’t be impossible to match a variety of car models, and with this aim we have proceeded since the (Suzuka) tests. From there, since we were shown three types of compounds, and in the severe environment of mid-summer Suzuka we checked the tendencies regarding performance and degradation over time, and this has been the focus of the tests this time. The aim was to choose six types of cars and to check a wide range of elements including power train and distribution of weight. Considering the fact that there were differences in the GTA-GT300 regulation cars and the FIA-GT3 regulation cars as well as the position of the engine in the GT3 cars, another aim was to check a car like the NISSAN GT-R NISMO GT3 with its low front and 330 size for their performance. By our expectations, we thought the lap times would be in the range of 1 to 1.5 seconds slower than those achieved with competition tires, but the impression this time is that the gap is in the range of 0.5 to 1 second. In that sense, more grip than we had expected was achieved. Since there will be a variety of conditions, it can’t be said for sure, but it appears that the outlook may be moving in a good direction. The west course at Suzuka has new pavement so it might have been difficult to measure the difference in soft, medium and hard specs. Also, since the conditions are different for a car with a 330 front package (NISSAN GT-R NISMO GT3), we may have to look at the data and think about how things will work out going forward. Since these are one-make tires, there are factors such as reducing the rigidity and prioritizing durability, as a company we will be taking good looks into what adjustments should be made.”
