SPD signal ECU

[firehawk]

The 180km/h limiter is mandated by japanese traffic law which requires that all new cars sold in the japanese home market are equipped with it. So if your engine is imported from Japan, it most likely has the limiter. This is usually overridden (well, raised to 360km/h - should be enough) with a simple frequency halving circuit which loses every other pulse. If you generate the SPD signal yourself with a reed switch, it'll be even easier - use only two magnets per revolution.