Option — Shōwa Car Tuning & Buyers Guide (2000 Edition)
An archive project by Flock MFGNew issue alerts →
About this issue
180 available scans from Option — Shōwa Car Tuning & Buyers Guide (2000 Edition), in right-to-left reading order. Japanese OCR and English translation drafts are available throughout. Drafts have not received exhaustive image proofreading; unreadable source remains recorded in the archival data.
Page 101 — English draft translation
The peripheral-ported 20B produces 450 PS in measured output. Unlike the quarter-mile setup, which revs to 13,000 rpm, this engine is shaped for efficient breathing around 8,500 rpm. Okada Engineering's 20B FC aims for 300 km/h without a turbo. The driver explains that unlike a turbo car, it needs revs to climb after entering the bank. The car therefore needs a rigid body with excellent weight distribution so the driver can enter the bank confidently. The 20B is about 20 mm longer than the 13B, so it sits roughly 10 mm farther back and 25 mm lower. The bulkhead, driveshaft, and members were modified. This preserves the original 50:50 weight distribution while increasing body rigidity...
Captions and page details
Swapped to a 20B! Naturally aspirated peripheral-port build targeting 300 km/h
Okada Engineering
Yatabe top-speed-spec FC3S with a 20B
This three-rotor FC was built for a top-speed feature in an automotive magazine. The 20B swap and resulting weight distribution received painstaking attention.
37000O0
The 20B was converted to a peripheral-port configuration centered around 8,500 rpm for top-speed running. This gives it a distinctive character for top-speed challenges, unlike a turbo setup.
The key to a top-speed tune!
ption
The FC's strength is how freely it can be modified.
Okada Engineering's 20B-powered FC has extensively modified chassis members.
The exterior stays nearly stock in appearance. The one-off stainless exhaust is original, with a 90 mm main pipe and a 100 mm outlet.
The suspension uses original adjustable-height aluminum coilovers. Since it is a naturally aspirated top-speed build, the goal is a setup that lets the driver stay firmly on the throttle through the bank.
For a straight-line top-speed run, that might be enough, but...
...for a top-speed attack that involves a bank, it is crucial that the body and suspension allow the driver to stay on the throttle through the turn. As the car transitions from vertical load to lateral G, its behavior can become unsettled very quickly. Body reinforcement and weight distribution must be reconsidered carefully.
Pan Speed, 2-7-8 Sekiyama, Hasuda, Saitama 349-0121; 048-764-2040. Okada Engineering, 1565-1 Miyakocho, Isesaki, Gunma 372-0801; 0270-25-9370.
Technical assistance: BORDER, 3-6-9 Nagaoka, Mizuho, Nishitama District, Tokyo 190-1232; 0425-57-7304
Option
99