Option — Shōwa Car Tuning & Buyers Guide (2000 Edition)
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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 80 — English draft translation
A 20-valve 4A-G swap presents several problems to solve. On this car, an Ultra simultaneous-ignition kit relocates the distributor, while the AE86's original wiring harness and ECU are retained. The ECU has been reprogrammed: it uses the 4-valve 4A-G map that operates TVIS, the variable intake system, to control the 5-valve engine's variable valve timing. The air conditioning and other electrical equipment still work, too.
OK Racing uses an AE111 20-valve engine. It has received a full tuning package, including Mahle forged pistons, connecting rods, a crankshaft, and high-lift cams. A Dems full-control ECU runs it, and that has another purpose: high-lift cams make the top end exciting but can dull response at low and midrange speeds. Fine control from the standalone ECU helps compensate for that.
Captions and page details
Engine swaps are the most important issue for the Hachiroku
The 20-valve 4A-G is an excellent foundation for a fully tuned engine. Its bottom end is designed to withstand high revs, and its cylinder head was revised to make power—making it completely different from the 4A-G originally fitted to the AE86.
AE86 Levin / Trueno
Motor Spirits Alpha Levin 20V
Looks like a stock Hachiroku on the outside…
…but underneath, it's an AE111!
An instant 40-PS increase!
The AE111 20-valve…
…is usable!
OK Racing Trueno
The standard four-throttle assembly on the 20-valve 4A-G is fitted with custom velocity stacks and left exposed. It just looks cool this way!
The distributor interferes with the bulkhead, so it is disabled and a simultaneous-ignition kit is installed here. This is an essential part of a 20-valve swap.
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Photos: Hiroki Iwashima. Report: Tadashi Uemura. With the cooperation of Motor Spirits Alpha, 3-13-1 Mikasa-gawa, Onojo City, Fukuoka 816-0912, tel. 092-503-1002; OK Racing, 1856 Shimohamada, Hamamatsu City, Shizuoka 435-0006, tel. 053-421-5151.