Now that DSC has posted its GT500 previews, which you can find below, its time to shift focus to the GT300 class, which is made up of GT3, JAF-GT and Mother Chassis. This two-parter begins with a look at JAF-GT and Mother Chassis entries.
GT500 preview links: PART 1 (Lexus), PART 2 (Honda), PART 3 (Nissan).
While these are two very distinct sub-classes of cars, the JAF-GT300 category and Mother Chassis cars are close enough to one another in terms of specs and performance that, at least on the surface, they are worth being grouped together for this portion of our 2018 Super GT preview.
But underneath the shell of these cars, they are very different machines all together.
The original JAF-GT300 category has fallen out of vogue in recent years, but still produces some of the most intriguing and exciting concepts in recent Super GT history. These are cars constructed from scratch by the manufacturers and constructors. The Mother Chassis, a platform launched in 2015, provides privateer teams and constructors with a common monocoque, a list of off-the-shelf common components including an ex-Nissan 4.5 litre V8 engine, for which any silhouette body can be built around it.
Once upon a time, all GT300 cars were built to JAF-GT300 regulations that the Toyota Prius and Subaru BRZ are built to, but the arrival of FIA GT3 at the start of the decade provided privateer teams with a more cost-effective solution just after a major recession. The Mother Chassis platform, then, was introduced as a cost-effective alternative to the FIA GT3s, one that would allow constructors and engineers more design freedom.
Where the GT3 cars find their advantage mostly on horsepower and awesome customer support from the manufacturers, these cars’ strengths lie in their downforce and light weight, with enough ponies under the bonnet to make it a fair fight with Balance of Performance factored in.
There is one less Mother Chassis entry this year, but there are still five very strong teams using the MC platform, coupled with three JAF-GT cars built by Toyota and Subaru:
Mother Chassis
Leaders of the Mother Chassis contingent are Tsuchiya Engineering, three-time GT300 champions who won it all with their Dome-built Toyota 86 MC in 2016.
They’ve reverted back to their old name, with a new title sponsor, and they’ve also brought in a new driver: Ultra-talented Toyota young driver Sho Tsuboi, who won two races last year with LM Corsa in their Lexus RC F GT3 and finished runner-up in last year’s All-Japan F3 Championship.
Tsuboi joins the brilliant duo of engineer and taskmaster Takeshi Tsuchiya, in his second year as deputy team director, with his increasingly-rapid protegé Takamitsu Matsui returning as the lead driver of the #25 Hoppy 86. They were quick at the Okayama test, and have consistently been the top challengers out of the Mother Chassis runners, and they’re determined to rebound after a shocking finish to their title defense last year.
Reserve driver and former Porsche Carrera Cup champion Tsubasa Kondo will spell for Tsuboi at the Fuji 500km.
Team Upgarage are a team with massive breakthrough potential in 2018, now an independent team after three years partnered with Racing Project Bandoh.
They’ve assembled a young, yet experienced and quick lineup of two former Honda GT500 drivers to lead them: 2013 GT300 champion Yuhki Nakayama returns for his fourth season as Upgarage’s lead driver, now joined by the exciting free-agent acquisition, former ARTA driver Takashi Kobayashi.
Team Upgarage have yet to score a podium finish in their three years in Super GT, but by adding Kobayashi, a race winner in GT500 last year, and a GT300 class winner every year from 2013 to 2016, to partner Nakayama, Makoto Ishida’s team is expected to deliver podium finishes, and their first GT300 win.
Team Mach have entrusted their Mach 5-inspired 86 to the youngest lineup on the GT300 grid. Former Honda young driver Natsu Sakaguchi returns to the team for his second season. His rookie teammate is Yuya Hiraki, a graduate of the FIA Formula 4 Japanese Championship.
Last year, with a youthful lineup and a new technical alliance with Tsuchiya Engineering, Team Mach ended a 7-year scoreless drought with an 8th place finish at Autopolis, and had the pace for more, were it not for some runs of bad luck. Expect this team led by longtime privateer racer Tetsuji Tamanaka to improve on their 2017 form.
In their second year, Saitama Toyopet GreenBrave and their funky Toyota Mark X MC look to build upon a solid finish to their trying debut Super GT campaign and score their first top-ten finish.
The fan-friendly GreenBrave squad, with their team of service mechanics turned race mechanics, will retain their veteran driver lineup of 2011 GT300 champion Taku Bamba, and GT300 stalwart Shigekazu Wakisaka, younger brother of Juichi.
The only mid-engined Mother Chassis is the Mooncraft-built Lotus Evora MC of Cars Tokai Dream28. They were one of the surprises of pre-season testing, following two lacklustre seasons and crashing into the cellar of the GT300 Teams’ Championship in 2017.
The long-tenured pro-am combination of Kazuho Takahashi and Hiroki Katoh, two time runners-up in the GT300 championship, remain together as they have almost every year since 2005. Katoh is still mega quick at 50 years old, but the pleasant surprise was 65-year-old gentleman racer Takahashi (oldest driver in the field) posting a genuinely quick lap at the Okayama test as well.
Dome Racing have taken over the general maintenance of the car, and Mooncraft have basically rebuilt the Evora from scratch with a new monocoque and redesigned aero. If their testing form holds true, it could be a dream season and return to form for Cars Tokai Dream28.
Toyota
One easy way to sell a new Super GT fan on the engineering ingenuity of the GT300 class is to tell them that there’s a mid-engined Toyota Prius with an ex-LMP1 V8 engine and hybrid system with as much downforce as a GTE car.
The two Toyota Prius GTs of apr Racing had a tough season in 2017, scoring only a single podium finish at Fuji in August. In year seven of the Prius project, the car may be showing a little age, but it’s still a capable machine with it’s RV8K engine, which is set to be retired after the season for a new Toyota customer racing engine.
Both Toyota Prius will now use the same capacitor-driven hybrid powertrain, which puts the number 30 car on even footing with the 31, but they will both use different tyre suppliers still, Yokohama for the #30, Bridgestone for the #31.
Two-time GT500 Drivers’ Champion Kohei Hirate returns to GT300 with apr, back for the first time since 2008. After a star-crossed 2017 campaign that saw him win a wild and memorable race at Sugo, only to be demoted after being caught up in a number of in-race clashes, Hirate is looking forward to his new challenge in the ultra-competitive GT300 class with the #31 Prius, the flagship car of the operation.
His co-driver is Koki Saga, another veteran who’s been part of apr since the start of the Prius project. Saga and Hirate did have a couple of incidents in testing, but they were also very fast at Okayama, and a driver of Hirate’s caliber can easily get them back in contention for victories on a regular basis.
The #30 car, running Yokohamas and now equipped with the more potent hybrid system, retains the pro-am duo of Hiroaki Nagai, and 2005 GT300 champion Kota Sasaki, the drivers who won last year’s Super Taikyu ST-X title with ARN Racing. Sasaki is still a top pro, and Nagai has improved as a true gentleman driver, so the #30 car is also due an uptick in form.
Subaru
Subaru and R&D Sport’s collaboration extends into 2018, and every element of the boxer-engined #61 Subaru BRZ has been refined for the season to come, from the turbocharged Flat-4 engine, to the aero, to the cooling, to the transmission.
All in another bid to capture a GT300 championship that Subaru just haven’t been able to compete for despite the years and funds invested into their factory GT300 programme.
The team have made no changes to their driver lineup of Takuto Iguchi and Hideki Yamauchi, who just missed out on a victory at Autopolis by less than a tenth of a second. They make no changes to their tyre supplier, their relationship with Dunlop still strong.
There is new leadership, with Subaru Technica International installing a new general manager in Makoto Shibuya to lead the sporting side at R&D Sport.
The 2016 Suzuka 1000km is Subaru’s only victory since the start of the Iguchi/Yamauchi era, and the team cannot afford to bookend their 2018 season the way that they had in 2017, starting the year with a mechanical DNF, and ending the year with back-to-back retirements, also attributed to mechanical failures.
Subaru’s supporters and their head staff are expecting this to be the year that they finally win a GT300 championship. Testing showed that the revamped BRZ has addressed some of its major weaknesses in performance from 2017, but it will be reliability and consistency that will define whether or not they will contend for the championship in 2018.
Images courtesy of: Toyota, Subaru, apr Racing, Team Upgarage, Natsu Sakaguchi, and the GT Association (GTA)
