Re: 98 Octane?

["David R Johnson" <johnsnd@domain.elided>]

Jorge,

sorry if I told you something you already knew.  The way I read your message it
sounded like the octane was the property you were interested in, so thats what
I concentrated on.  As I understand it, a general rule is that higher octane
fuels burn more slowly, which is how they avoid detonation.  This I believe to
be true at least for standard street fuels.  I think high-octane street fuel
may actually contain less available energy than lower octane fuel, but I am not
sure on this point.

I am not very knowledgable about the race formulations, so it may very well be
possible to extract more energy in a shorter time with a properly formulated
race gas.  I know for example that the methanol powered dragsters often use
high compression ratios (in excess of 14:1) _and_ superchargers without
detonation problems, but I don't know how the other properties of methanol
compare to regular gas.  Sorry I can't provide any further information, I just
wanted to make sure you were not expecting a power increase from the octane
boost alone.

Thanks,

Dave J. (needing more patience to avoid double-posting - doh!)
1982 GTV6 (some assembly required)

On Mar 31,  9:39pm, JMazlumian wrote:
> Octane rating is only one of the fuel qualities.  I know that higher octane
> alone will not do much unless there is a turbo or supercharger and hence
> compression is increased.  I mentioned it for ID purposes.  However, fuels
> have other qualities such as Burning Speed, (the speed at which a fuel
> releases its energy.  If the fuel is still burning after peak cylinder
> pressure, it's a waste, and perhaps counterproductive).  Energy Value, an
> expression of the potential energy in the fuel, measured in BTU's per pound.
> Cooling Effect, related to the heat of vaporization, the higher, the better,
> but granted, more inportant in 2 stroke engines than in 4 stroke.
> So I thought that these higher quality racing fuels might be of some
> benefit.  Since I have no racing experience I thought I ask.  By the way I
> failed to mention they cost about 3 times more!

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