Event: HKS Premium Day 2018 V.2 – Option Fuji Super Lap

There are always the core shops that participate in the Super Lap event at HKS Premium Day annually.  Names like Pro Shop Fukoh, Top Fuel, Garage G-Force, Auto Select, Esprit, Top Secret, Autech and the like; which is awesome because you get to see what amounts to basically a yearly update of how the cars have been getting on.  Development in time attack moves just about as fast as the cars nowadays, so it’s no surprise to see builds looking completely different year over year, as they put more and more research into obtaining as much aerodynamic grip as possible.

Speaking of which, we got to witness a somewhat frightening example of just how much downforce these cars are garnering at speed (more on that later).  I mentioned in the last article, that it seemed as if attendance was down this year comparatively.  However, for the fact mentioned above, their are staple shops of the sport that invest heavily into HKS and their products, that make it a point to attend each year.  So, despite a lower turn out, getting to see these particular shops benchmark their demo cars is along worth the trip out to Fuji Speedway.  Conditions this year were pretty good, although a bit colder than usual.  No doubt that the turbo cars are heavily favored in conditions where ambient air temps are low, which usually translates to faster times.  In Japan, the time attack season is held over the winter, where temps can range from the mid 40’s (Fahrenheit) to below freezing in the mornings.  Personal bests and records are consistently set in the first session of the day.  Tire warmers are used without question, so as soon as the out lap is over, the drivers are already on to setting times.  It’s a combination that allows the veterans to capitalize on ideal conditions, but puts a large emphasis on preparation.  Using data collected by logging their hot laps, shops and drivers will study the performance of the car and work tirelessly throughout the weeks leading up to events in order to remedy what prevented them from going faster.  It’s an accumulation of preparedness and skill that sets fast laps, and the participants of Super Lap are some of the best examples.

One of the most well know of all, is the Top Fuel S2000RR.  Having been a pioneer in working with Voltex to exploit as much aerodynamic grip as they could out of the chassis, it’s debut at HKS Premium Day some time ago set a bar for the rest to follow.  It’s return to Fuji in 2018, however, didn’t go as planned.

No stranger to high power builds, Top Fuel refreshed the motor which meant the S2000 was now pushing upwards of 900 horsepower – a significant increase in comparison to their last outing at Fuji, and one that may have ultimately lead to their early retirement.

Not having run the car since 2015, they had high hopes of returning to the mountainous venue to beat their previous time of 1’39.131, having improved from their 2014 time of 1’40.195.  The day started out somewhat smooth, setting a few very comparable times in their first outing.  On the last hot lap of the first session they were able to seal in the fastest time of the day for the 2WD class, as well as beat out their 2015 time with a 1’39.044.  That victory, albeit a memorable one, would turn out to be bittersweet come the end of the day.

Heading back out for the final session of Super Lap in the afternoon, the track conditions had held strong.  Cloudy weather ensured that the same conditions from the morning were maintained throughout the day, with temps lingering below freezing for the entire event.  All was on target to break into the 38’s, when the engine let loose, spewing coolant and oil over the underside of the car.  Top Fuel’s reign had ended.

Unfortunate to say the least. Whether or not their small victory was enough for them to justify rebuilding and sending it back out again next year is still up in the air.  Regardless it was nice to see it perform one more time at the famed Speedway.

Remember how I mentioned that we were able to bear witness to a frightening, albeit tangible, example of the downforce the modern day aero is achieving?  Well this is what I was referring to:

Towards the end of the front straight, the Evolution’s front passenger tire exploded, in a very unexpected fashion.  Luckily, Taniguchi was able to control the car to a stop, and walked away without incident.  I wrote something about this in the TRB-03 article I published last month, so I’ll just quote the majority of it here to reiterate:

The intense amount of downforce that these aero kits are making puts a very increased amount of stress on the tires causing much greater deformation than normal conditions. All of a sudden, vertical and lateral sidewall deflection solely due to aerodynamic grip becomes a factor. S-type tires weren’t necessarily designed with these stresses in mind, and as you’ll see shortly in our coverage, or may have already seen from other sources, this very topic became an issue for Garage G-Force at HKS Day when they suffered a burst tire towards the end of the main straight. Initial speculation was that the shear speed the EVO achieved, due in part to Fuji Speedways lengthy front straight, increased the downforce that the Voltex kit made enough to push the body into the tire shredding it. Some cited too soft of springs, despite them running somewhere in the range of a 38k-42k weight front spring. What actually seemed to have occurred though, was that the downward force generated at those speeds simply was too much for the tire to withstand.

Voltex engineers confirmed this after getting a chance to look at the tire, but regardless, it ripped the entire left fender off completely, and heavily damaged the front splitter, side skirt and under-tray, effectively ended the day for the team.  Not before they were able to secure the fastest lap of the day by a long shot though, with an incredibly fast 1’37.381; nearly 2 seconds faster than the Top Fuel S2000RR.  This time was achieved during the first Super Lap session, in which the car was in top form.

And clearly it was, as Taniguchi wouldn’t have been able to pip that 37 in a car without proper setup.

Unfortunately, G-Force weren’t the only team subject to bad luck that day.  In fact, this year’s HKS Day was the most incident filled event I’ve been to in a long time.  Reliability isn’t something I typically consider an issue at these events, simply for the fact that it’s not something I see plaguing the sport here in Japan.  All in all, four teams competing in Super Lap suffered major mechanical failures for one reason or another.  Top Fuel blew their motor in the last session, Garage Mak’s R35 threw a rod early in the day, the incident above with G-Force, ATTKD’s R35 was plagued with issues early on that prevented it from competing, as well as a handful of other difficulties throughout the paddock.

It didn’t take long for the Mak R35 to let go.  With Odori-san behind the wheel he was able to grab a 1’45.564 – which was good enough for fifth in the 4WD class.  No doubt they’d be able to get more out of the car if they had not suffered an early out.

Interesting enough, when I entered Esprit’s garage, I wasn’t treated to views of their flagship NSX, but to their newer 86 demo car.  Equipped with the HKS GTII turbo kit, tailored specifically for the FA20, the car produces a healthy amount of power – which we all know is one place the 86 is lacking in.

Modified RB over fenders allow proper airflow, as well as provide space for the wide Prodrive wheels and Bridgestone tires.

The car has been given a healthy dose of carbon treatment both helping to reduce the overall weight, and gain an aerodynamic advantage.  Custom front splitter, carbon mirrors, hood and GT wing are all staples of the Esprit shop.

Rear center exit exhaust sounded menacing coming down the front straight.

The team struggled with the setup though, and was only able to grab a 2’18.251 – at least the car looks great.

Back at it with one of the most bizarre choices in chassis selection, the guys at Prime Garage commissioned their C35 Laurel to compete in Super Lap once again.  With a major engine overhaul since last time I saw it, Tatsuya was able to grab 2nd place this year in the 2WD class, finishing second only to the Top Fuel S2000 – impressive!  Although the 1’47.772 was almost a full 8 seconds off pace from the 1st place powerhouse, the difference between Prime Garage and the third place finishers was only a few tenths.  I was stoked to see them beat out the competition with the C35.It is definetely a car that attracts a lot of attention both on and off the circuit.For good reason – just look at it!

Biting at the heels of the heavy sedan was a car that we’ve seen several times at Attack events in the past, but I’d never seen at Fuji – the Material Auto Supra.

The car is clad in a mixture of carbon and fiberglass Tamon Design body panels, and it’s somewhat iconic white and carbon cutaway livery.   Utilizing an HKS T04Z turbine, the 2JZ puts out a healthy 680ps which is plenty for the times Tatsuo Kitada has set for himself.  The combination of the well-developed car, and Kitada’s driving, placed him squarely in third place in the Super Lap 2WD class, securing the position with a time of 1’47.920.  It’s pretty cool to compare the average speed of the JZ and the C35, as they were nearly identical on their best laps – what a good match!

It’s wild to see this car barrel out of corners at full throttle – it looks so much larger to others in comparison.

Masahiro Sasaki and his team at Wing-Takeo brought out their R35 again to compete in the 4WD class.  With a solid drive, as usual, they were able to secure the last spot on the podium in the 4WD class with a 1’43.076 – just shy of breaking into the 42’s and losing out to Garage Ito by just one tenth.  The car has made immense strides from 4 years ago when it was running the 50 second range.

The car remains relatively unchanged from the outside, while the team relies solely on setup changes to best their times year over year.  An updated front end was introduced this year that gives the car a more aggressive look, and I’m sure helps with directing airflow.

Original Runduce was present in their Varis clad Subaru and although noncompetitive as far as times go, the car looked absolutely stunning.  This car makes a great case for the Subaru fans that message me constantly wanting to see more Subaru content.  Unfortunately, for whatever reason you want to pick, the platforms are just absent from time attack compared to the handful of other chassis that are so prominent in the sport.

I mean, just look at it…

From nearly any angle, the Varis kit does well to transform the mild mannered exterior of the new STi’s into a much for dramatic looking, aerodynamically efficient sports car.

Some of Arvou’s customers were competing in the Hiper Challenge.  Neither got podium winning times, but they definitely looked good enough to include in the coverage.

One of my personal favorites that run Super Lap consistently are the crew from the Mie based shop, Fukuoh.  Kataoka and his gang fell in the middle of the fray this year with a 1’50.605.  An unfortunate decrease in their times as they are typically in the mid to high 40 second range – they struggled with the tuning throughout the day, eventually settling for 6th place finish on the time sheets.

I like the new splitter fences – I see a lot of cars moving to a setup like this.

Extremely well organized engine bay.  It’s difficult to make rotary bays tidy, but there are a couple shops that seem to do it no problem – Pro Shop Fukuoh is among them.

A look at the interior of the shop car.

Out on track the car sounded normal, but you could tell that the corner exit speed of the FD was slightly slower than those ahead of them in the time sheets.

Cars like the Garage Ito R34 – a GTR that has been consistently fast throughout it’s development, giving cars with twice as much aero and power a run for their money.  It’s a testament to the fact that you can still have a very fast car that’s focused solely around tuning, than aerodynamics; something that often gets lost int his day of aero improvements.

Here you can see the team throughout the day making corrections in correlation to the feedback the driver, Hiroyuki Iida, gave them after each session.  The car is a performer, no doubt.  With the perfect conditions during the first outing, they were able to stop the clock with a 1’42.930 just slightly faster than the Takeo R35.


Although among the simplest looking of the cars in Super Lap, it’s usually one of the most well performing cars in the event.  If not only for a great day of racing, Super Lap provides a chance to see the shops various tuning philosophies in action.  It’s for that reason that it is still among my favorite of the year.


  1. Nice work mate! Definitely an event I want to get to.

  2. So many of these cars are not really taking advantage of the information we have on aero now. I’m not seeing many gurney flaps, decklid spoilers, 3d diffuser (both vertical and horizontal), double diffusers, front diffusers, swan neck wing mounts, etc.

    Also, many of these machines have wings fastened to the rear decklids, which is a total waste of time. These cars don’t seem like they need all that much braking because they don’t spend much time out on track to get a single laptime, so they could probably run some pretty small brake ducts and aerodynamic wheels, too.

    In my philosophy as an engineer, I absolutely go crazy with the cheap stuff, so when people spend so much money for parts that are not installed properly or optimized it kind of irks me a little bit. Just one simple course on fluid mechanics will reveal so much to you. It’s basically sad to see how people copy flawed designs from each other.

    The racer that develops a car that is way ahead on the first iteration is going to have a solid base from which to build a faster car.

    There’s a ton of development still to go with these machines. I’m surprised, they don’t seem to follow LeMans type cars.

    http://www.mulsannecorner.com is a really great website to get new ideas for aero designs. People should absolutely take advantage of the efforts of the big companies, they pay major money to develop those cars, and at the end of the day, it’s pretty easy to incorporate many of those design philosophies.

  3. sorry, I misspelled that, can’t find an edit button. http://www.mulsannescorner.com/

  4. Nick Generazio

    Jon….No one cares about you being an engineer. ^

  5. Any shots of the white other white supra parked behind the Material Auto Supra?

  6. Pingback:Feature: Garage G-Force – The Evolution of the Yamazaki IX

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