[texan]

If you can make greater voltage, yes it's true. Once the spark has jumped the gap additional voltage makes no significant increase in spark size, but increasing the gap along with enough voltage to jump it certainly does. Companies love to show pictures of how "hot" the spark is and so forth, but I've seen better evidence that increasing the gap with a strong coil makes much more difference in power output than just increasing the voltage. Also remember this is assuming there's something inadequate about the current setup, which if the motor is NA and fairly stock is not the case.