Option — Shōwa Car Tuning & Buyers Guide (2000 Edition)

As you push a naturally aspirated tune further, you will inevitably want the engine to rev higher. With an injected engine, the key is how far the ECU's maps can take you. That is where MoTeC control comes into its own. In a highly developed naturally aspirated injection setup, people tend to remove as many correction functions as possible. Then, as with a carbureted car, the engine becomes sensitive to air temperature and pressure. MoTeC lets you build the maps from the ground up, so the engine can be controlled to suit each individual engine.

Raising compression also depends on fuel and ignition tuning. If the ECU or carburetor settings are wrong, an engine with a higher-than-stock compression ratio can knock and eventually suffer engine failure, so take care. The 4A-G's original D-Jetronic system already has limited scope for control, and the stock ECU has a low ceiling. For precise control, MoTeC offers an additional level of capability…

In the 16 years since its debut, the 4A-G has continued to evolve. Later Levin and Trueno models advanced to 20-valve engines with four individual throttles, and parts from those cars transformed the world of Hachiroku tuning. The AE111 in particular brought fundamental upgrades to parts such as the connecting rods, pistons, and cylinder-head design. By using those parts—or swapping in a complete 20-valve engine—tuners achieved higher power and revs; naturally aspirated 4A-G builds making around 200 PS are no longer unusual. As engine power and vehicle speed rise, the tires and suspension must keep pace. Tire grip is much higher than it was at the car's debut, which calls for a firmer suspension and then a stronger body. This level of tuning represents the leading edge of today's Hachiroku scene and gives people a reason to think, ‘Maybe I should drive an AE86 again.’