I was sent this response from Turbobuicks.com website member GNX7 concerning octane boost. Here is a cut and paste of the threads:
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GNX7-
When you mean octane booster I hope you don't mean out of any can you can get from your local auto parts store. When they say they bump it up 3 to 7 points they mean to following: 92 octane becomes 92.3-92.7

You should check out your local paint distributor and get a 5 gallon container of Xylene (117 octane) or Tuolene(114 octane).

7 gallons of 92
3 gallons of Xylene 3 ounces of Marvel Mystery Oil yields 100 octane safely.

Adding only one gallon to 7 gallons of fuel will yield around 94.5 octane which will help with poor fuel octane quality.
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Carfixxer-
How much does a 5 gal can of that cost? Does it have any ill effects on pump, injectors, seals, etc?
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GNX7-
I think I paid $32 for 5 gallons of it. It is a component of gasoline and won't hurt anything as long as you stay at/below the 30% mix ratio.
People have been running it for years without problems.
-GNX7
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So I tried this today because all they have in Hawaii is 92, (Ultra-PING)
Home Depot sells pure Xylene in a 1 Gal ($10.) can its not as cheap as the 5 gal but it was late on a Sunday. And it worked great I ran the car up a tourture test hill and had my scanner monitoring and there was a 75% reduction in knock counts. And it was something you could actually feel with your right foot!

 

Good info there. I've been throwing around the idea of trying something like that myself. The other day, I pulled my coil wire off the cap and cranked it over and it still did ole "wants to start studder" for a breif moment. When it runs though, i don't hear any audible knocks or pigs. I have the Holley Knock sensor kit for my HSR system so I guess it's time to hook it up, lol.


Tom

 

you know, if you pour several bottles of store bought octane booster in, it has the same effect..


i believe street cars should be made to run on street fuel... now in the case of boosted cars, i can understand the desire to run higher boost (andtherefore need more octane) at the track..

thats what race gas is for. at the track, its still cheaper then $10 per gal last time i checked...

 

[GNX7-
When you mean octane booster I hope you don't mean out of any can you can get from your local auto parts store. When they say they bump it up 3 to 7 points they mean to following: 92 octane becomes 92.3-92.7 ]

That is so wrong......
When I was running octane boost instead of 100 octane unleaded, I forgot the stuff one day and made a run without it, much to my horror the car ran 14.10 @ 94mph. I went and got the stuff and poured it in and the very next run produced 13.32@102. There is no way that was just a .3-.7 increase.

(NOS street octane boost is not the good stuff)

 

if you were teetering on the edge before, that could be enough to move you from the edge back into the safe zone.... think about it, cars ping on 89 but not 91? thats only 2 points diff..... fact is, with EFI, you can get very close to the edge...

 

Octane is a detonation retardant( basically making gasoline less flammable) the whole idea is keeping pre detonation down if you put higher octane fuel in a engine but do nothing with the timing you havent accomplished anything. On computer controlled engines the ecm will keep the timing pushed to the max via the knock sensor on non computer controlled engines you have to find your max timing advance for the level of octane you are running
Advance is a good thing if you can keep the "ping gremlins" under control

 

You know, I have read that somewhere as well. I think that's a turbobuick myth that has floated around quite a bit.

 

I dont know too much about octane boost, but I did notice much different winaldl readings when running a bottle of 104 octane boost. Knock count dramatically decreased among other things.

 

Call the makers of Octane booster they never claim to raise octane 3-7 NUMBERS! It says 3-7 POINTS.

I did my own test on my own car I put 1 can of NOS street octane boost w/ 92 octane as per their directions. Drove up a steep incline at 1/2 throttle on the highway with my scanner attached and it was knock count 60.
Week later after that tank was near empty same hill, same weather, 1 gal. xylene 5 gal 92.
70% drop in knock! And I could feel thedifference.
My car has the turbo buick engine so its more sensitive than a 305 350 etc,.
These automotive chemical companies make a foutune off claims like this. Another example is motorflush, which is kerosene in a 18 oz. can at the price you can get 2 gal.
I put this info out to people like me who live in an area where hi-grade fuel is not available and the track out here does not have race gas pump. The auto stores sell race gas in a can but its $58. for 5 gal. I just know it works and if people claim its a myth, then its fine with them. To anyone not sure I say do some research, make some calls, whatever but I put this post to alert everyone that 3-7 points is not numbers.

 

now, put the same amount of xylene as you did octane booster... or put in a gal of octane booster like you did with the xylene...

its the same chemicals....

fact is, on any kind of a road trip or daily driving, i donno about you guys, but i dont want to carry a gallon of ANYTHING...

now if my pushed-to-the-edge-on-premuim motor needs a can of octane boost to make up for some bad fuel, thats fine.... keep a small can of it, or even a bottle of xylene in the rear hatch compartment... but you shouldnt need this stuff on a street motor to begin with..

 

Xylene and octane booster is NOT the same.
Xylene and toulene is a distillate of petroluem on a higher level than gasoline.(without getting too technical)
Octane booster may contain xylene or toulene but its main additive ingedient is MMT if you add a gallon of octane boost you will foul your plugs and o2 sensor,in no time and eventually foul out the catalyst for those who still have them. Then you will lower the octane rating believe it or not!
Hey this is not for everyone......but sometimes this is what an individual has to do to meet performance requirments on their own personal vehicle. And this information is helping you with that choice.

 

My opinion is that some folks are taking this in the wrong direction. There is way to much hype floating around here.

1. The knock sensor does not allow a motor to run on the edge of detonation, under the factory tune the knock sensor pulls ALOT of timing out of the curve as the knock sensor reports to the ecm, hence slower. The KS is a safety device not a realtime integrated self tuning device for the ECM.

2. One gallon of 100_race_gas can not be compared to one gallon of toulene. It would take multiple gallons of 100_race_gas to raise the total octane level of a full tank of gas that 1 gallon of toulene would accomplish. At least double the price.

3. A factory engine combination is tuned to run on pump gas, 91 octane in performance cases. However not all mechanical devices, ie: the engine, have identical requirements. Then add age, mileage, poor air density, high temps, etc... to the eqaution and you may run over the border of detonation. A can of 104+ or NOS booster may bring you back within the circumstance of control. OVER THE COUNTER OCTANE BOOSTERS ARE NOT DESIGNED TO ALLOW A HIGH PERFORMANCE ENGINE WITH COMPRESSION AND EXTREME LEVELS OF PISTON SPEED TO OPERATE ON THE STREET OR TRACK PROPERLY!!!!!!!!!!!!! I HOPE EVERYONE GETS THIS!!!!!!

4. If by chance in this free country someone decides to build a high performance high compression motor they first off better know exactly what they are doing or they will fail from the get go. Polished combustion chambers, cold air intake, proper quench, proper spark plug heat range, proper dynamic compression ratio, and the list goes on.

Now for my .02

Anyone who is smart enough to make it past the above point #4 can run whatever the helll they want for fuel as they will have already sunk enough time and money into their motor to know what they are doing. They can run AV_Gas, Toulene, 100_Race_Gas, or Xylene to maximize ET at the strip. However I would also venture to guess that someone that smart will be running considerably less timing advance on the street to keep the motor safe.

 

Putting it in simple terms the ecm will try to advance timing until it determines that there is to much advance ie knock, once that has happened it will retard timing briefly then start advancing once again until it is too far advanced, this happens at incredably fast pace but it is a continuing battle between advance and retard once again this is a simplifed version (bottom line more octane less knock more advace) I personally would not run anything but good fuel that is also why I have a MSD timing contol so I have 15 degrees of timing contol from the drivers seat but I also dont have a computer controlled fuel and ignition system

 

Anyone that wants further info. on this subject needs to visit corvetteforum.com. These guys have years of experiece with this octane boost. I also have my own exp. with toulene. I have a 12:1 motor, in which I did everything possible to keep out heat form the chambers, except coated headers, and I'm able to effectively run 93-94 oct with NO detonation. Of course this was with temps in the 30s and 40's so I'll see what it does when I get it out of the garage this spring. Even if I do detonate a little when it gets warmer, there's nothing a little toulene cant fix. It's simple math really. Take 10 gals 93 gas (66%) 5 gals toulene 115 oct (33%) and you get the equivilent to 100 oct. race gas for much cheaper assuming you can get a 55 gal drum of toulene from a local paint manuf. for about $4.50 a gal.