Octane vs Timing

[Marc Lublin]

Does anyone know if there is some kind of formula in regard to advancing the timing when using higher octane fuel in a SC car. For example if at 93 Octane I am pulling 10 degrees of timing out at 10lbs of boost, what could I put back in as far as advance goes if I were running on 100 octane fuel. I recently found a station here on Long Island that sells Sunoco 100 octane unleaded, so it would be nice to fill up with it and have a secondary program ready when I do. I know there are no absolutes, but just want to see if there is a general rule.

 

[Bill B]

No real formula that I know as there are many factors. But with 100 octane you should be able to add about 2 degrees.

 

[KenH]

I had pulled this info off one of the SC manufacturers sites. Not sure which one.

1° spark advance = +0.5 octane
1 air/fuel ratio = +2 octane
20° temp = +1 octane

-- Ken