The Basics on Why Static Ignition Timing Affects the Powerband
A brief and basic description of why static timing adjustment affects the powerband. This will help you understand why the MSV Racing “Faraday” High Power Adjustable Stator can dramatically change you engines powerband and over all power potential. Adjusting the static timing allows you to set your CDI’s ignition map to the type of powerband characteristics you want from your engines set-up.
Retarding the timing reduces the hit of the powerband in the low and mid-range, but extends the top-end and over-rev. The reason is that the temperature in the pipe increase with the retarded timing. When the timing is retarded, the burn cycle starts later and continues into the pipe. Raising the exhaust gas temperature raises the velocity of the waves, making them more in time with the piston speed and port timing of the cylinder.
Advancing the timing increases the low and mid-range hit of the powerband, but makes the power flatten out at high rpm. The earlier spark lead time causes a greater pressure rise in the cylinder before TDC. This produces more torque in the low and midrange, but the high pressure contributes to pumping losses at high rpm.
As a general rule the more you advance the timing from your current OEM setting the higher the fuel octane required. This requirement will depend on YOUR build, elevation, tuning etc.
Note*MANY if not MOST people running a race fuel are way over octain’d for their engine’s needs.