Tsukuba Circuit is hallowed ground within the time attack world, but for many enthusiasts outside Japan, the dream of hitting this iconic track in real life stays just that – a dream.
For Jacky Tse of JTune, a Latest Zealand-based tuner and die-hard time attack fan, nevertheless, that dream wasn’t something to simply watch from behind a screen. It was something to be realised.
Jacky considers himself a “normal driver.” While he’s an off-the-cuff track instructor, Jacky shouldn’t be knowledgeable racer. His goal was easy but ambitious: to prove that anyone could show as much as Tsukuba for the primary time in a street automobile and leave with a lap time that might sound unachievable for a novice enthusiast.
In fact, there was one crucial piece to this puzzle – the automobile itself.
Shipping a automobile from Japan to Latest Zealand is reasonably priced, given the huge variety of used JDM vehicles exported each week. But sending a automobile in the wrong way? That’s a special story. I’ve covered the same story where 4 Australians shipped their drift cars to Japan for a month of track days, and I’ve kept tabs on their ongoing adventure. From Australia or Latest Zealand to Japan, automobile shipping costs are only the tip of a really expensive iceberg – and that’s before you think about the return trip.
For Jacky, sending a automobile from Latest Zealand didn’t make financial sense. A significantly better idea got here during Tokyo Auto Salon 2024.
A 12 months ago at Makuhari Messe, HKS unveiled a wide-body GR86 to showcase a fresh initiative for the corporate: The HKS. Drawing from over 50 years of tuning experience, this division has been set as much as create fully built street cars for patrons – from mild to wild. Knowing HKS already had a successful time attack GR86 in its R&D fleet, Jacky asked if he could purchase the automobile on display, with the intention of taking it to Tsukuba. The reply wasn’t completely straightforward.
Initially, Jacky was told he could buy the prototype ‘The HKS’ GR86, but because it transpired, the automobile had already been sold – to a different Jacky, which can explain among the confusion. It wasn’t all lost though. If he was willing to attend, HKS could construct one other automobile – ‘The HKS’ GR86 customer chassis #1 – after which run it with him at a Tsukuba time attack event.
This feature turned out to be even higher. Jacky could spec the automobile exactly how he wanted inside the boundaries of what HKS defined as a ‘street automobile,’ and have time to properly prepare for the driving challenge. Just a few months later, a contract was signed, the deposit paid, and in June, ‘The HKS’ division began work on a brand new Toyota GR86 RZ in Crystal White Pearl.
By August, the core of the construct was finished. By December, it was fully accomplished – just in time for the second and final 2024 HKS Tsukuba Hiper Challenge. That is once I joined Jacky and over 40 of his family and friends for the occasion.
Before diving into how the day unfolded, let’s take a take a look at the automobile…
At a look, it’s clear this is not any unusual GR86. Street legal? Yes. Subtle? Not even close. The automobile sports a full HKS Type-R body kit, widening the front by 55mm and the rear by 65mm (per side). That is further enhanced by HKS SPL CRFP (carbon fibre reinforced plastic) canards, vortex generators, and an under-panel, together with a custom HKS SPL CRFP swan-neck GT wing –all of which were CFD-tested to enhance high-speed stability.
The GR86 runs two sets of 18×11-inch +30 Yokohama wheels – Advan GT Beyonds and Advan Racing TC4s, which were wrapped in Yokohama Advan A050 295/30R18 semi-slicks for Tsukuba. HKS Hipermax R coilovers enhance the automobile’s handling while Infinite 6-pot front and 4-pot rear brakes ensure it could stop.
Inside, the full HKS catalogue has been unleashed.
There are HKS fiftieth (anniversary) Bride Zeta IV front seats, HKS fiftieth TRS 6-point harness belts, and an HKS fiftieth Nardi Sports 34S steering wheel. Not forgetting its street automobile credentials, HKS floor mats and a luggage mat within the trunk complete the look. For its day on the track, the passenger Bride seat and mats were removed, but the whole lot else remained.
Finally, the powerhouse and HKS’s bread and butter of the construct – the engine. From its original 2.4L naturally aspirated specification, HKS stroked the GR86’s flat-four to 2.5L using their Short Block Step 2 kit, which incorporates forged pistons, I-beam connecting rods, and a forged crankshaft with a crank key.
To bring the ability, an HKS GTIII-RS turbo kit was added, complete with the turbocharger, exhaust manifold, 113mm catted downpipe, intercooler, and a Super Power Flow air filter. Supporting the upgrades are a wide range of HKS parts, including a grommet-type head gasket, Fantastic Tune V-belt, Hi-Power SPEC-L II exhaust system, and an S-Type oil cooler kit. Dress-up parts, just like the HKS dry carbon fibre engine cover (removed in these photos) and fuse box cover, and the HKS oil filler cap, complete the engine bay.
The GR86’s factory ECU stays, however it now has an HKS F-CON sub-ECU, HKS EVC 7 boost controller, HKS ATK A/F Knock Amp, and an HKS VAC II (speed limiter removal) running alongside it. The ability output? With 0.7bar (10.3psi) of boost dialled up, a conservative 350hp.
This was the total HKS catalogue construct, with no cut corners. Nonetheless, Jacky had an additional request above and beyond the scope of the driveline upgrade, which initially just added an HKS LA (Light Motion) clutch: Fitting a race-spec limited-slip differential, and a Quaife 69G 6-speed sequential transmission from Momentum Motorsport in the UK, one in all Jacky’s long-standing partners.
At first, HKS wasn’t fully on board with this deviation. But when Jacky showed up on the Fuji HQ mid-build with a Cusco RS 1.5-way LSD in his carry-on luggage and the news that the Quaife gearbox was en route, the team got here around. In any case, even HKS had encountered issues with stock GR86 transmissions failing under boost heading in the right direction, and a broken box was the very last thing Jacky desired to have prematurely cut short his day at Tsukuba.
Originally, Jacky was purported to get some test laps before the Hiper Challenge, but as often happens with these projects, the construct went right down to the wire. His first time behind the wheel could be on the event itself. And with only three short 15-minute sessions to work with, laying down a decent lap time – Jacky’s goal being sub-1-minute – was going to be anything but easy.
The day began with high spirits, but things took a fast turn. Jacky hadn’t even made it out of the pit lane when the engine stalled and couldn’t be restarted. After the automobile was pushed back to the HKS pit, the problem was traced to a loose crank angle sensor. Session one: done.
To properly solve the sensor issue, the transmission would wish to come back out of the automobile to present full access to it. There was no time for that, so a side-of-the-road fix was employed, allowing Jacky to move out for session two.
Jacky had been preparing for this present day for six months, running tons of, if not hundreds of laps on his simulator. But Tsukuba’s real-world elevation changes, corner camber, and track narrowness were all things he needed to quickly adapt to. Through the second session, he was understandably cautious, knowing that crank angle sensor failure at speed could end in disaster. Moreover, the automobile was understeering, and the brakes weren’t performing as they need to, mostly since the pads hadn’t been bedded in and the suspension settings needed tweaking. The massive aero was hampering its straight-line speed too. Still, Jacky lapped at 1:03, a solid start.
After some tweaks and with confidence that the crank angle sensor issue wouldn’t resurface, Jacky equipped for the third and final session. He had a technique: warm up on lap one, then push for a time on lap two, and lap three if essential.
There was immediate improvement with a 1:01 first lap. But on lap two, the engine began to overheat, initially causing power loss after which a misfire. Jacky returned to the pits for a cool down, but on his return to the track the misfire endured. Not wanting to risk the engine, the session was called.
Although the teething issues didn’t allow Jacky to hit his lap time goal, the GR86’s performance was impressive for a primary shakedown.
Hit play above to ride together with Jacky for a couple of laps around Tsukuba.
At the tip of the day, Jacky noted, “This project wasn’t just a couple of construct or a lap time. It was about fulfilling a lifelong dream with my family and friends, and celebrating automobile culture at Tsukuba, the world’s most iconic time attack track.”
While this was purported to be a one-hit Tsukuba deal, with HKS returning the GR86 to its HQ after the event and immediately prepping it for export to Latest Zealand, there’s a likelihood Jacky will get a second shot at that 59-second lap before Japan’s 2024/2025 time attack season is over. HKS has fixed the crank angle sensor issue and is currently fine-tuning the setup, so we’ll see.
Within the meantime, you must definitely take a look at Jacky’s YouTube channel, Seat Time, where his ‘Road to Tsukuba’ has been documented intimately.
Alec Pender
Instagram: noplansco
This Article First Appeared At www.speedhunters.com
