Above all the classes in Japanese time attack, the ‘Naturally Aspirated’ group has become known for developing it’s own set of interwoven rivalries among the drivers. Whether it’s for the fastest NA time overall, the FF NA record, or chassis specific contention, there’s sure to be close battles on track each season.
The S2000 challengers specifically, have become a fixture of this public infighting within the NA class. Season after season, the times continue to drop, leaving only those that push themselves both on track and with off-season developments at the front. Drivers like Juroku Tomiyoshi and his Imola Orange ‘Fura’ S2000 have had to bow out, unable to keep up with the frontrunners – despite having extremely competitive times (57.376 for Juroku). The intense competition has left just two main competitors standing; an almost David vs. Goliath setting (…kind of…). Yoshitaka vs. Hiroki, Arvou vs. ASM.
If you currently search for ‘The Fastest NA S2000’, or ‘Tsukuba NA S2000 Record’, you’ll be overwhelmed by incorrect search results from 2018 or so from when Hiroki Katoh in the ASM S2000 set his, at the time, record lap of 57.051. Seeing as Yoshitaka Ishii broke that record years ago, after ASM halted development on their car, I figured it was high time we attempt to change that. I suppose it’s partially our fault; we haven’t really highlighted the Kimidori S2000 since 2018 in this article here. While we did write an extensive feature on Shibata and Arvou last year, which featured a gallery of Yoshitaka’s current setup (you can view that here), we just briefly mentioned his old NA S2000 record of 56.855 – nowhere else in the article did we really highlight that he was the current record holder in this regard. This article featured photos of the newly built 2.4 liter F22C, which is still being used this season. This current engine makes upwards of 350hp, about 30hp more than the previous engine. Where his car has shown the most improvement though has been in the overall weight. The pair have gotten the AP1 down to a mere 1,000kg (a mere 2,200 pounds), and are looking to reduce that even further.
This season, Yoshitaka is no longer using the prototype Winmax calipers he had been testing. Instead, he opted for a new Endless kit in order to reduce weight; unsprung weight at that. Aside from that, and small changes in suspension and ride height tuning, the car is relatively the same as last season. On December 25th 2022, Yoshitaka updated his NA Record at Tsukuba with a 56.426 – just shy of a half second improvement. In talking with Shibata this week, he mentioned that they are aiming to dip into the 55 second range next season with this current setup.
With ASM slated to return to Tsukuba as well, we are excited to see these two back on track together. No doubt it will make for some good racing.
Here are the current, notable S2000 standings:
Taniguchi – Top Fuel S2000 – 51.762 (set in 2016!)
Yusaku Shibata – ARVOU Supercharged AP1 – 53.887
Yoshitaka – ARVOU NA – 56.426 (current S2000 NA Record) – updated 12/25/22 A050GS
Hiroki Katoh – ASM NA S2000 – 56.875 (Attack 2019)
Juroku ‘Fura’ Tomiyoshi – IMOLA Orange NA S2000 – 57.376 (retired – return unknown)
Enjoy the gallery and in-car of his record lap.
Shibata and Ishii work very closely together, to the point where Ishii’s S2000 is very much representative of what Arvou is capable of. Although he is a privateer and customer of Arvou, Yoshitaka’s S2000 has become very much like an Arvou demo car.