The Tsukuba circuit is holy soil in the time attack world, but for most enthusiasts outside of Japan the dream remains to enter this iconic circuit in real life exactly: a dream.
For Jacky TSE However, from Jtune, a Tuner and Die-Hard Time attack fan established in New Zealand, that dream was not something to just look from behind a screen. It was something that had to be realized.
Jacky regards herself as one “Normal driver.” Although he is a normal job instructor, Jacky is not a professional racer. His goal was simple but ambitious: prove that everyone could appear for the first time in a street car at Tsukuba and could leave with a round time that may seem unfeasible for a starting enthusiast.
Of course there was one crucial piece in this puzzle: the car itself.
A car shipping from Japan to New Zealand is affordable, given the huge number of JDM vehicles used that is exported weekly. But send a car the other way? That is a different story. I told a similar story in which four Australians shipped their drift cars to Japan for a month of circuit days, and I have monitored their continuous adventure. From Australia or New Zealand to Japan, the shipping costs for cars are just the tip of a very expensive iceberg-and then you have not included the return trip.
For Jacky, sending a car from New Zealand was not useful financially. A much better idea arose during Tokyo Auto Salon 2024.
A year ago, HKS unveiled a GR86 with a broad body at the Makuhari Messe to demonstrate a new initiative for the company: The HKS. Based on more than 50 years of tuning experience, this division was established to create fully built street cars for customers-from mild to game. Know HKS already had a successful time attack GR86 in its R&D fleetJacky asked if he could buy the car exhibited, with the intention of taking him to Tsukuba. The answer was not very easy.
Initially, Jacky was told that he could buy the prototype ‘The HKS’ GR86, but it turned out that the car had already been sold – to another Jacky, which could explain part of the confusion. However, it was not all lost. If he was willing to wait, HKS could build another car-‘the HKS’ GR86 customer chassis no. 1-and then let it ride with him during a Tsukuba time attack.
This option turned out to be even better. Jacky was able to specify the car exactly as he wanted, within the limits of what HKS described as a ‘street car’, and he had the time to prepare well for the riding challenge. A few months later a contract was signed, the deposit paid and in June the ‘The HKS’ division started with the construction of a new Toyota GR86 RZ in Crystal White Pearl.
The core of construction was completed in August. In December it was fully completed – just in time for the second and last HKS Tsukuba Hiper Challenge of 2024. This is the moment when I added to Jacky and more than 40 of his friends and family for the occasion.
Before we comment on how the day went, let’s first look at the car …
It is clear at a glance that this is not an ordinary GR86. Street legal? Yes. Subtle? Not even nearby. The car is equipped with a full HKS Type-R body kit, where the front is widened by 55 mm and the back by 65 mm (per side). This is further improved by HKS SPL CRFP canards (with carbon fiber reinforced plastic), vortex generators and a bottom panel, together with a customized HKS SPR CRFP GT wing with swan neck-all of which are CFD tested to improve the high speed Stability .
The GR86 has two sets of 18×11-inch +30 Yokohama wheels: Advan GT Beyonds and Advan Racing TC4s, who are covered with Yokohama Advan A050 295/30R18 Semi-Slicks for Tsukuba. HKS Hipermax R-screw sets improve the driving behavior of the car, while the endless brakes with 6 pistons in front and 4 pistons behind ensure that the car can stop.
Inside, the full HKS catalog has been released.
There are HKS 50TH (Jubilee) Bride Zeta IV preferences, HKS 50th TRS 6-point harness belts and a HKS 50th Nardi Sports 34s steering. And last but not least the characteristics of a street car, HKS floor mats and a luggage mat in the trunk complete the look. For his day on the circuit, the passenger seat and the mats were removed from the Bride, but everything else remained.
Finally the powerhouse and the bread and butter from HKS: the engine. From the original 2.4 liter atmospheric specification, HKS has brought the flat-four from the GR86 to 2.5 liters using their short block Step 2-kit, which is forged pistons, i-beam-rods and a forged stoolshaft with a cranks key.
To convey the power, a HKS GTIII-RS turbo kit was added, complete with turbo compressor, exhaust manifold, 113 mm Catted Downpipe, Intercooler and a Super Power Flow-Air Filter. In support of the upgrades, a variety of HKS parts is supported, including a head gasket of the implementation type, Fine Tune V-Riem, Hi-Power Spec-L II Exhaust system and a S-Type oil cooler set. Dressing parts, such as the HKS dry carbon fiber bonnet (removed on these photos) and the lid of the fuse box, and the HKS oil filler cap, complete the motor compartment.
The factory ECU of the GR86 will continue to exist, but it now has an HKS F-Con Sub-ECU, HKS EVC 7 Boost controller, HKS ATK a / F Knock AMP and a HKS VAC II (removal of speed limiter) next to it. The power? With a boost of 0.7 bar (10.3 PSI) that is a conservative 350 hp.
This was the entire construction of the HKS catalog, without cuts. However, Jacky had an additional request that went beyond the upgrade of the powertrain, in which only a HKS LA (Light Action) coupling was added: mounting a racing-specific spare differential and a quaife 69g sequential six-speed gearbox of MominSport in the United Kingdom, one of Jacky’s long -standing partners.
In the first instance, HKS did not quite agree with this deviation. But when Jacky appeared in the middle of construction at Fuji headquarters with a Cusco RS 1.5-way LSD in his hand luggage and the news that the quaife gearbox was on the road, the team came by. After all, even HKS had encountered problems with standard GR86 transmissions that went under boost on the circuit, and a broken container was the last thing Jacky wanted his day at Tsukuba would be demolished prematurely.
Originally it was intended that Jacky would run a number of tests before the Hiper Challenge, but as often happens with these projects, construction went to the limit. His first time behind the wheel would be at the event itself. And with only three short sessions of 15 minutes to work with, putting down a respectable lap time – Jacky’s goal was less than 1 minute – anything but simple.
The day started cheerfully, but things quickly took a turn. Jacky had not even come out of the pit lane when the engine turned off and could not be started anymore. After the car was pushed back to the HKS-Pit, the problem could be traced back to a separate stool corner sensor. Session one: ready.
To properly solve the sensor problem, the transmission should come out of the car to get full access. There was no time for that, so a solution was applied to the side of the road, allowing Jacky to go to session two.
Jacky had prepared for this day for six months and drove hundreds, if not thousands of laps on his simulator. But Tsukuba’s height differences in the real world, corner equation and narrowness of the track were all things that he had to adapt quickly. During the second session, he was understandably careful because he knew that a defect on the crank -corner sensor could end up on a disaster at high speed. Moreover, the car had understeer and did not perform the brakes as they should, especially since the brake pads were not embedded and the settings of the suspension had to be adjusted. The large aerodynamics also hindered the speed in a straight line. Yet Jacky drove a round of 1:03, a solid start.
After some adjustments and with the confidence that the problem with the Krukhoeksensor would no longer pop up, Jacky prepared for the third and final session. He had a strategy: warming up in the first round, then pushing for a while in the second round and if necessary in the third round.
There was an immediate improvement with a first round of 1:01. But in the second round the engine started to overheat, which initially caused power loss and then caused a misfire. Jacky returned to the pits to cool down, but on his return to the track, the misunderstanding continued to exist. Because I did not want to risk the engine, the session was invested.
Although Jacky was unable to achieve his lap time goal due to the teething problems, the performance of the GR86 was impressive for a first shakedown.
https://www.youtube.com/watch?v=KRAPIKEEP-Q
Press ‘Play’ above to ride a few laps around Tsukuba with Jacky.
At the end of the day, Jacky noticed: “This project was not only about building or lap times. It was about fulfilling a lifelong dream with my friends and family, and celebrating the car culture on Tsukuba, the world’s most iconic time attack circuit. ”
Although this would be a one-off Tsukuba deal, where HKS brings the GR86 back to the head office after the event and immediately prepares it for export to New Zealand, there is a chance that Jacky will get a second chance in that round of 59 seconds before. The Japanese time attack season 2024/2025 is over. HKS has solved the problem with the Krukhoeksensor and is currently refining the setup, so we will see.
In the meantime you should definitely view Jacky’s YouTube channel, Sitting timeWhere his ‘road to tsukuba’ is documented in detail.
Alec Pender
Instagram: No Planco
