Originally Posted by
venom2727 but this only happens when launch is activated ? meaning after launch the tach will read accurately ?
Yes, with spark cut enabled, the ignition signal is interrupted to keep one or more plugs from firing. While this is happening, the signal to the tach is also interrupted and the tach needle jumps around, but only when the rev limiter is active. When the launch speed is exceeded, or the RPM is below the launch rev limit, the tach reads normally.
I'll add an option to enable spark cut while launch rev limit is active. This will be in addition to the anti-lag retard and fuel enrichment features.
Dave