luscombe

if one used unleaded 100+ octane racing fuel, would the detonation sensor allow more spark advance, and therefore result in higher HP?

the inverse is that using lower octane results in retarded advance and less HP. i think i know this.

thanks

doug

jasoncool

i have used 100 octane in mine and let me say! i can tell a big difference however this fuel is so expensive that it prevents me from doing it often

Admiral

Higher octane is worthless unless you truely need it (compression, psi, n2o). Save your money and pass on the race fuel unless you want to pay for the smell.

The idea of higher octane to prevent detonation (hence spark retard) is totally valid. In a stock and even most modified (head/cam) motors, race fuel is a waste of money!

luscombe

i realize that higher octane than what is needed is a waste, but my question is " does the knock sensor allow more advance when using higher octane fuel, which would result in higher HP ".

it may be that Chevy programed a maximum spark advance, optimum based on 93 octane, and using higher octane has no advantage, but if Chevy programed the spark advance to increase until knock was sensed, then, higher octane would result in higher HP.

thanks

doug

HalM

Dyno results are showing that the C6 yields nominally more horsepower if you increase the octane. My butt meter agrees.

Race tracks out here (Like Sears Point) have 91 and 100 unleaded race fuel. It's fun to do once but not a very practical solution for everyday driving...Unleaded race gas mixes approximately linearly. So if you have a half tank of 91 and you top off with 100 you get about 95-96 octane...

luscombe

thank you, i thought it would increase HP but not sure, and i knew it wasn't an everyday practical way to get an increase,

doug

SCZ28

If you aren't getting any knock retard then higher octane won't give you more spark advance. There are spark tables and knock retard tables with fixed values(a big matrix).

Also remember that you can have false knock that causes retarded timing so it isn't always from detonation. A degree or two of timing is not worth a significant amount of hp.