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Old 10-03-2002, 10:49 AM
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Post Octane vs performance

My 428 runs just fine on 87 octane gas. I have been reading about the home brew octane boosters and got to wondering if my car would benefit from higher octane or if I am just wasting my money. Here is the formula:

To make eight 16 ounce bottles (128 oz = 1 gal):
o 100 oz of toluene for octane boost
o 25 oz of mineral spirits (cleaning agent)
o 3 oz of transmission fluid (lubricating agent)

Adding 10% Toluene to the gas would increase octane rating about 2.4.

Does a higher octane gas tend to burn cooler? What are some of the other side effects? If I switch to 92 how long will it take to notice any difference if I do? Since octane reduces knock, I would be able to advance my timing some but if it is already at optimum total and no knock, would there still be a benefit?

I know this is an old question. A little more pondering probably wouldn't hurt.

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Old 10-03-2002, 10:57 AM
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There is really no benefit in running higher octane than your engine requires. Gasolines, regardless of octane rating, generally have the same amount of BTUs per pound which is about 20,000 BTUs per pound of fuel. There is alot more to fuels than one would suspect, however.
If your engine runs fine on 87 without detonation, I wouldn't bother mixing octane boost, or buying higher cost fuels.
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Old 10-03-2002, 01:25 PM
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Just out of curiousity, where in the heck did you get that formula?

It actually sounds crazy, like someone pulled it out of their butt!

Why do people think they need octane boosters? If they want to run higher octane, just mix pump gas with racing gas.

Anyways,

Jason
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Old 10-03-2002, 01:29 PM
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[QUOTE]Originally posted by Mertz:
[QB]My 428 runs just fine on 87 octane gas.

END OF STORY. i agree w/nairb. my truck lugs bad at @ 1500 rpm when i ran regular, but doesn't with shell or 76 mid-grade, but did again with AM/PM premium, so gas is different. at least am/pm gas sucks. but i wasnt able to say my motor ran fine on 87 as you do, so stick with 87.
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Old 10-03-2002, 01:37 PM
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The formula has been posted on many web sites. It is about the same as the formula of the prepackaged octane boosters. I understand some people just use straight toluene.
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Old 10-04-2002, 07:33 PM
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Dig this man, octane is ,{R+M)/2, a rating of a grade of gasoline to resist detonation. If your FE motor is running fine on that fire water you've got in it, don't worry about.
the more you raise the octane the slower the gasoline burns, that why you can raise your ignition timing to make more power. I've only see the pure stock muscle car boys do something similar, one guy had a 73' 401 amc javalin, they've got about 8.5:1 c.r. and he ran 106 octane and jacked the timing to about 41 degrees B.T.D.C., and it seemed to help his E.T.'s, so unless you are drag racing I would'nt mess with it ever.
I almost forgot, if you were going to raise go for performance, there is some stuff known as nitropropane, not nitromethane, this stuff mixes with gasoline and it carries 2 molocules of oxygen along with alot of carbon, the rule of thumb is to increase your jet size my 1 size per percentage point of nitropropane, it's like having a little bit a N20 without the plumbing, expect about 10% more power with the maximum 10% mixture, oh by the way you might want to invest is some colder heat range spark plugs and retard the timing a few degrees when experimenting with it. remember lean = pistons through hood.

[ October 04, 2002: Message edited by: Jay396 ]</p>
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Old 10-05-2002, 08:29 AM
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Note on NAIRB's comment on heat content of fuels - that rule of thumb works for any hydrocarbon fuel. Natural gas, propane butane, jet fuel, gasoline, crude oil, all generate very near the same heat per pound of fuel. I use 18,000BTU/# (lower heating value) instead of 20,000BTU/# (higher heating value) but either is close enough for government work.

High octane does nothing more than allow higher compression w/o pre-ignition. Use the lowest grade you can without ping. In fact, I have worked as an engineer for oil companies for 33 years and with what I know about fuels, I buy the cheapest gas I can that isn't loaded up with alcohol. I know some people swear buy one brand or another and I don't want to offend them but from everything I have learned, and I have access to some pretty high level info, the only difference in gasolines is the octane rating and price.
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Old 10-07-2002, 09:59 AM
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Isn't the only difference is gas brands the additive packages they use?
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