J-Rod

As stated, upping your octane without having something to take advantage of that extra octane is a waste. More octane does not equal more power. As correctly stated below more octane = resistance to detonation. Once your fuel isn't detonating adding more octane just slows down the burn.

Xylene and Toluene are better to use than most over the counter octane boosters that contain nasty stuff like MMT (like Torco). Lots of Vette guys in Cali like Torco, and it is pushed alot on some other sites. I personally wouldn't run it. Xyelene and Toluene are already in fuel, you're just upping the percentages. Also Xylene and Toluene are in many of the other octane boosters, you see in stores. The differnece is, you can buy a few gallons of Tolune or Xylene for what it costs to buy a small bottle of octane booster.

Here are some good guides on it.

http://www.gnttype.org/techarea/misc/octanebooster.html

http://www.gnttype.org/techarea/misc...explained.html

The only time you will see any more power with higher octrane fuel is if generates more BTUs/hr than your normal fuel and/or it is oxygenated to allowing more air/fuel in the chamber (we're talking about max of ~5Hp on an engine dyno).

S_J_H

Only problem with toluene is it is a very sooty fuel. You'll notice the plugs will carbon foul easily at higher %'s.
And if you leave it in the tank to long you'll find yourself fouling plugs in a matter of seconds. I made the mistake of leaving a 30% toluene mix in my tank over the winter and have never seen a fuel go so bad in 3 months!

J-Rod

Toluene is actually very clean burning. If you have soot, you have the ratio too high, and incomplete combustion.

Toluene is a pure hydrocarbon (C7H8). i.e. it contains only hydrogen and carbon atoms. It belongs to a particular category of hydrocarbons called aromatic hydrocarbons. Complete combustion of toluene yields CO2 and H2O.

Because toluene is such an effective anti knock fuel it also means that it is more difficult to ignite at low temperatures. The Formula 1 cars that ran on 84% toluene needed to have hot radiator air diverted to heat its fuel tank to 70C to assist its vaporization. Thus too strong a concentration of toluene will lead to poor cold start and running characteristics. I recommend that the concentration of toluene used to not exceed what the engine is capable of utilizing. i.e. Experiment with small increases in concentration until you can no longer detect an improvement.

God Forgives I Dont

here is some more information on the Homebrew Octane Booster. I haven't tried it yet, but I am going to get some soon to see it for myself.

http://www.ls1camaro.net/sections.ph...ticle&artid=63

http://www.ls1camaro.net/sections.ph...ticle&artid=64

Patman

When I mentioned how the Fuel Power product raises the "effective octane" by one point, it does mean one octane rating. So putting this stuff in 91 octane gas gives you the same knock retard readings that 92 octane would.

S_J_H

Have you much experience using toluene? I have used quite a bit of it. I read all the net info on it years ago which is what got me interested in it.

Well like much on the internet I feel there is a lot of exaggeration going on with this subject. It works but is not all that great IMO.
First off, we don't get complete combustion. That's not possible especially when your running poweradders and NEED a rich A-F mix.And most guys who need more octane are using a poweradder.
Most power adder guys run from 11.0-12.0 A-F mixes. That leaves behind a lot of unburned fuel and the resulting chemicals from incomplete combustion. Benzene is also a byproduct of incomplete combustion of toluene.
The very first thing I noticed when I began using toluene and xylene was increased carbon on the plugs. I pull plugs religiously as a part of my tuning. Nothing major but I did notice it.But the fuel did breakdown horribly when I left the mix in the tank for 3 months.I thought I had somehow ruined my pcm it ran so bad. I finally figured out it was the fuel that had gone bad.

Toluene is not an easy fuel to vaporize also. It does smell. Anybody who has ever made plastic models will recognize the smell as it's the primary chemical in plastic model cement. Load 30% or greater in your tank and your car smells like model cement.
It's not cheap either. I don't know when the internet articles on this were first posted. But it's usually around 8$ per gallon at most places unless you buy it by the drum.

To get any real effect from it IMO you need at least 30% mixed with pump 93 octane IMO. If you need less octane than 100, I would suggest tuning the motor to just run fine on 93 as I don't see why you would want to mess with mixing fuels for a final octane under 100.

I normally ran 3 gallons to 5 gallons of 93 pump about a 37% mix. That gave me ~ 100.5 octane and worked out to about 4.20$ gallon for 8 gallons of fuel in the tank. I can just buy a true 100 octane unleaded locally at the gas station for around the same price and it works better. So I stopped using toluene.

I have tried Torco many times, both the leaded and unleaded. Unleaded version seems to be LOADED with MMT as it will really color the plugs burnt orange. It works good but not sure how hard it is on the o2's or cats.

For the open loop guys with no 02's who can't find race fuel, there is octane supreme 130- http://www.kemcooil.com/product_info.php?pId=61

It can take pump gas up to 109 octane. It's real lead and that is still the best octane booster ever developed.

Steve

SSINFUL

Best response. Listen to him.