Chasing The Dream: Tsukuba Time Attack In An HKS-Built GR86

Tsukuba Circuit is hallowed ground in the time attack world, but for most enthusiasts outside Japan, the dream of hitting this iconic track in real life remains just that – a dream.

For Jacky Tse of JTune, a New Zealand-based tuner and die-hard time attack fan, however, that dream wasn’t something to just watch from behind a screen. It was something to be realised.

Alec Pender  - Speedhunters HKS-179
Alec Pender  - Speedhunters HKS-11

Jacky considers himself a “normal driver.” While he’s a casual track instructor, Jacky is not a professional racer. His goal was simple but ambitious: to prove that anyone could show up to Tsukuba for the first time in a street car and leave with a lap time that might seem unachievable for a novice enthusiast.

Alec Pender  - Speedhunters HKS-26

Of course, there was one crucial piece to this puzzle – the car itself.

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Shipping a car from Japan to New Zealand is affordable, given the massive number of used JDM vehicles exported each week. But sending a car in the opposite direction? That’s a different story. I’ve covered a similar story where four 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 New Zealand to Japan, car shipping costs are only the tip of a very expensive iceberg – and that’s before you factor in the return trip.

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For Jacky, sending a car from New Zealand didn’t make financial sense. A much better idea came during Tokyo Auto Salon 2024.

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A year ago at Makuhari Messe, HKS unveiled a wide-body GR86 to showcase a fresh initiative for the company: The HKS. Drawing from over 50 years of tuning experience, this division has been set up to create fully built street cars for customers – 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 car on display, with the intention of taking it to Tsukuba. The answer wasn’t completely straightforward.

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Initially, Jacky was told he could buy the prototype ‘The HKS’ GR86, but as it transpired, the car had already been sold – to another Jacky, which may explain some of the confusion. It wasn’t all lost though. If he was willing to wait, HKS could build another car – ‘The HKS’ GR86 customer chassis #1 – and then run it with him at a Tsukuba time attack event.

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This option turned out to be even better. Jacky could spec the car exactly how he wanted within the boundaries of what HKS defined as a ‘street car,’ and have time to properly prepare for the driving challenge. A few months later, a contract was signed, the deposit paid, and in June, ‘The HKS’ division began work on a new Toyota GR86 RZ in Crystal White Pearl.

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By August, the core of the build was finished. By December, it was fully completed – just in time for the second and final 2024 HKS Tsukuba Hiper Challenge. This is when I joined Jacky and over 40 of his friends and family for the occasion.

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Before diving into how the day unfolded, let’s take a look at the car…

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At a glance, it’s clear this is no ordinary GR86. Street legal? Yes. Subtle? Not even close. The car sports a full HKS Type-R body kit, widening the front by 55mm and the rear by 65mm (per side). This is further enhanced by HKS SPL CRFP (carbon fibre reinforced plastic) canards, vortex generators, and an under-panel, along with a custom HKS SPL CRFP swan-neck GT wing –all of which were CFD-tested to improve high-speed stability.

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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 car’s handling while Endless 6-pot front and 4-pot rear brakes ensure it can stop.

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Inside, the full HKS catalogue has been unleashed.

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There are HKS 50th (anniversary) Bride Zeta IV front seats, HKS 50th TRS 6-point harness belts, and an HKS 50th Nardi Sports 34S steering wheel. Not forgetting its street car credentials, HKS floor mats and a luggage mat in the trunk complete the look. For its day at the track, the passenger Bride seat and mats were removed, but everything else remained.

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Finally, the powerhouse and HKS’s bread and butter of the build – 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 includes forged pistons, I-beam connecting rods, and a forged crankshaft with a crank key.

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To bring the power, 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 variety of HKS parts, including a grommet-type head gasket, Fine Tune V-belt, Hi-Power SPEC-L II exhaust system, and an S-Type oil cooler kit. Dress-up parts, 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.

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The GR86’s factory ECU remains, but 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 power output? With 0.7bar (10.3psi) of boost dialled up, a conservative 350hp.

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This was the full HKS catalogue build, with no cut corners. However, Jacky had an extra request above and beyond the scope of the driveline upgrade, which initially just added an HKS LA (Light Action) clutch: Fitting a race-spec limited-slip differential, and a Quaife 69G 6-speed sequential transmission from Momentum Motorsport in the United Kingdom, one of Jacky’s long-standing partners.

At first, HKS wasn’t fully on board with this deviation. But when Jacky showed up at 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 came around. After all, even HKS had encountered issues with stock GR86 transmissions failing under boost on track, and a broken box was the last thing Jacky wanted to have prematurely cut short his day at Tsukuba.

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Originally, Jacky was supposed to get some test laps before the Hiper Challenge, but as often happens with these projects, the build went down to the wire. His first time behind the wheel would be at the event itself. And with only three short 15-minute sessions to work with, laying down a respectable lap time – Jacky’s goal being sub-1-minute – was going to be anything but easy.

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The day started with high spirits, but things took a quick turn. Jacky hadn’t even made it out of the pit lane when the engine stalled and couldn’t be restarted. After the car was pushed back to the HKS pit, the issue was traced to a loose crank angle sensor. Session one: done.

To properly solve the sensor issue, the transmission would need to come out of the car to give full access to it. There was no time for that, so a side-of-the-road fix was employed, allowing Jacky to head out for session two.

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Jacky had been preparing for this day for six months, running hundreds, if not thousands of laps on his simulator. But Tsukuba’s real-world elevation changes, corner camber, and track narrowness were all things he had to quickly adapt to. During the second session, he was understandably cautious, knowing that crank angle sensor failure at speed could end in disaster. Furthermore, the car was understeering, and the brakes weren’t performing as they should, mostly because the pads hadn’t been bedded in and the suspension settings needed tweaking. The big aero was hampering its straight-line speed too. Still, Jacky lapped at 1:03, a solid start.

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After some tweaks and with confidence that the crank angle sensor issue wouldn’t resurface, Jacky geared up for the third and final session. He had a strategy: warm up on lap one, then push for a time on lap two, and lap three if necessary.

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There was immediate improvement with a 1:01 first lap. But on lap two, the engine began to overheat, initially causing power loss and then a misfire. Jacky returned to the pits for a cool down, but on his return to the track the misfire persisted. Not wanting to risk the engine, the session was called.

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Although the teething issues didn’t allow Jacky to hit his lap time goal, the GR86’s performance was impressive for a first shakedown.

Hit play above to ride along with Jacky for a few laps around Tsukuba.

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At the end of the day, Jacky noted, “This project wasn’t just about a build or a lap time. It was about fulfilling a lifelong dream with my friends and family, and celebrating car culture at Tsukuba, the world’s most iconic time attack track.”

While this was supposed 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 New Zealand, there’s a chance 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.

In the meantime, you should definitely check out Jacky’s YouTube channel, Seat Time, where his ‘Road to Tsukuba’ has been documented in detail.

Alec Pender
Instagram: noplansco

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11 comments

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1

Props to Jacky, getting a 1:01 with a car you basically had less than an hour to get acclimated to is still quite the feat

2

Thanks, had less than 20 Laps the whole day running. The first outing was just make sure nothing falls off! Pretty sure the car will go faster if there was no fault on the day. But it’s a Day1 car and first time driving the car and the track, can’t expect to be prefect! But it was close! Hopefully we get a re run very soon!

3

The same lap times as a 991 GT3 RS. Not bad.

4

Hopefully once is tided up and fix up the driving the driving, we can shave abit more time off :)

5

How long have you been driving on tracks? Do you have any background in competition or is this more just for fun? Your driving is the most important thing to consider, but if you are knocking 1-2 seconds off from minor setup changes this would imply both the car and your track knowledge have room for improvement.

Until you are capable of clocking times within 0.500 consistently your driving should be the primary focus. You are also missing some low hanging fruit in the form of removing your side mirrors for drag. Unless these are required to run at Tsukuba they are doing nothing to help lap times. Shaving door handles is also low hanging fruit.

Not a bad time at all for a first outing. I think you can crack the 1 minute barrier for sure.

6

Im not a pro driver, seasonal racer or have done karting.
I just like to drive and this is a track that i loved to have a go on since a kid.
Im sure any JDM car enthusiast will be the same.

yes yes, the car had few fault on the day so we didnt get a prefect run. Im happy with the time for first outing. Pretty sure there is more time in it as it.
It is a full trim street cars with bolt on and nothing has been cut out or massive weight reduction

Ther Craftsqaure Mirrors was not fitted due to production time. But the concept of it for HKS, the car need to be complete or the same as their Concept. I would love to fit dry carbon bonnet and doors and boot to it.

If you have time check out seat time nz on youtube :)
And Yes! Hopefully we get a re run and will send it properly next outing!

7

I looked up your run around Tsukuba. Not bad driving, looks like you are still getting comfortable with the machine and the track. It takes a pro driver around 3-5 laps to get within 90% of what a vehicle can do. Would say getting a 59 at this point could solely be down to you getting more seat time.

The main reason I say this is I didn't notice any counter steering or movement from the chassis which implies the driver is where my attention would focus. I am mainly looking at your steering inputs. As you have said sounds like you are still learning so seat time, seat time, seat time.

Nice laps and build. You're very dedicated to the sport to do this. Before buying carbon bonnet, doors, and boot, I would take some money and work with a reputable coach in your area. I bet you could go 1.5 to 2 seconds faster with the car as it is right now.

Good luck. Have fun. God Bless.

8

thanks for watching!

The bonnet is more to get rid of
the heat or to lower the temp down. It won’t last a session at full pace, so it’s hard to actually get proper seat time.

I only had 20laps or really just 20min in the car, the first 10 or session was just making sure the car runs fine and getting a feel for it all.

Now with data and had a feel of the car and the track, I will know where I could go faster and shaved off sometime!

It’s one of those tracks, go slow to go faster! Throwing it in with speed doesn’t work well comparing to slowing right down and just let it flow around to turns.

Let’s see what I can do!
Need to make sure we actually get or secure a re run first!

Will do my best as always :)

9

Hi again Jtune,

Reliability is the most important thing in a circuit based racing car. If you can't do full sessions due to overheating this is the first thing that should be sorted out. Hard to get better if you can't consistently lap back to back to back.

As far as getting faster and improving I think analyzing data is something you could look at, but will not benefit you much at this point. You simply need to drive faster everywhere to get the car to start to act "wrong."

With regards to going slow to go fast: this is a good way to look at things in the beginning as an amateur, but you will find as you gain more experience that you need to go fast everywhere. Slow down to go fast is one of my least favorite phrases in driving. I was a professional coach for quite some time.

Generally speaking, corner entry is the final place where you will find lap times. You are wise at this point to focus on slowing into the corners so you can make sure you get a good exit and carry good speed mid corner. This also helps you adjust the attitude of the car easier as you don't have to make a correction and the get the car "back on line."

Right now I would say get your car reliable and then work with a proper coach. You have a long way to go but this is an excellent start. I hope to see you break the 1 minute barrier and accomplish your goals.

10

Yes!, Lets see what happens!
Long as the car is handle it, will just keep cutting laps and compare lines and data!
If there is next outing in this car there, improvement has to be made, just need few more faultless laps we should be in!

11

Undoubtedly a very cool story and I have to pay respect to Jacky for his driving and effort. But the story is way too far from "His goal was simple but ambitious: to prove that anyone could show up to Tsukuba for the first time in a street car and leave with a lap time that might seem unachievable for a novice enthusiast."

Someone who can afford to pay HKS the GDP of a small country or arrive at Japan carrying a 6 speed sequential gearbox doesn't quite fit the definition of a novice enthusiast. Moreover, we can argue all day about the definition of a street car and a normal driver. What he actually proved is that if you have the available resources and a crazy idea, you can make a cool story.

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