So I mixed 5gl of toluene with 8gl of 93 yeilding 106oct? not big difference on X but much smoother.

[spartanS4]

Gonna go up 5 degrees and see what happens. I just haven't felt any gains when running on 100 octane with x stg 3.

[PSmalls::DoggieStyle]

[No More B5 S4]

[M3KILR]

[M3KILR]

[Audi2ptzero]

you have to add a little more fuel. Same goes when you start to increase the boost levels.

[PSmalls::DoggieStyle]

[Audi2ptzero]

Nice thing about my car is I just get out and turn the fuel pressure down at the rail. I am sure glad I went that way because I need to run 40psi on the street and 50-52psi at the track.

[evils4]

thats what alot of guys did when I raced motocross.

[Rican_S4]

Here is some info i've come upon on different forums but *USE AT YOUR OWN RISK*

SUNOCO "Standard"
Color...Purple
Research Octane...115
Motor Octane...107
R+M/2 ...111
Specific Gravity...0.725
Reid Vapor Pressure... 8#
Distallation temp, degrees F
Initial...90
10%...160
50%...220
Final...360


SUNOCO "GT Unleaded"
Color...Natural
Research Octane...105
Motor Octane...95
R+M/2 ...100
Specific Gravity...0.760
Reid Vapor Pressure... 8#
Distallation temp, degrees F
Initial...90
10%...150
50%...210
Final...230

SUNOCO "Supreme"
Color...Blue
Research Octane...116
Motor Octane...109
R+M/2 ...112
Specific Gravity...0.715
Reid Vapor Pressure... 8#
Distallation temp, degrees F
Initial...90
10%...155
50%...215
Final...260

SUNOCO "Maximal"
Color...Red
Research Octane...118
Motor Octane...115
R+M/2 ...117
Specific Gravity...0.700
Reid Vapor Pressure... 6#
Distallation temp, degrees F
Initial...100
10%...150
50%...220
Final...240


Richard Lassiter's "How to Mix Your Own Brew"

FORMULA 1
Toulene
R+M/2...114
Cost...$2.50/gal
Mixtures with 92 Octane Premium
10%...94.2 Octane
20%...96.4 Octane
30%...98.6 Octane
Notes: Common ingredient in Octane Boosters in a can. 12-16 ounces will only raise octane 2-3 *points*, I.e. from 92 to 92.3. Often costs $3-5 for 12-16 ounces, when it can be purchased for less than $3/gal at chemical supply houses or paint stores.


FORMULA 2
Xylene
R+M/2...117
Cost...$2.75/gal
Mixtures with 92 Octane Premium
10%...94.5 Octane
20%...97.0 Octane
30%...99.5 Octane
Notes: Similar to Toulene. 12-16 ounces will only raise octane 2-3 *points*, I.e. from 92 to 92.3. Usually mixed with Toulene and advertised as *race formula*.


FORMULA 3
Methyl-tertiary-butyl-ether (MTBE)
R+M/2...118
Cost...$3.50/gal
Mixtures with 92 Octane Premium
10%...94.6 Octane
20%...97.2 Octane
30%...99.8 Octane
Notes: Oxygenate. Very common in octane booster products. Has lower BTU content than toulene or xylene, but oxygenate effect makes the gasoline burn better and produce more energy.


FORMULA 4
Methanol or Ethanol
R+M/2...101
Cost...$0.60 - $1.75/gal
Mixtures with 92 Octane Premium
10%...94.3 Octane (Methanol)
10%...94.7 Octane (Ethanol)
20%...Not Recommended
Notes: Methanol is wood alcohol. Ethanol is grain alcohol and found in Gasohol in 10% ratios. Both alcohols are mildly corrosive and will eat gas tank linings, rubber and aluminum if used in excessive ratios. Main ingredient in "Gas Dryers", combines with water.


FORMULA 5
Isopropyl Alcohol and Tertiary Butyl Alcohol
R+M/2...101
Cost...$0.60-$1.50/gal
Mixtures with 92 Octane Premium
10%...94.5 Octane
20%...Not Recommended
30%...Not Recommended
Notes: Similar to Methanol/Ethanol. Isopropyl Alcohol is simply rubbing alcohol.

When oil companies blend their gas, they have to mix the cheap stuf, usually 'straight run' components, with the good (high octane/expensive) stuff. It is a fine balancing act, they run as much of the cheap stuff as they can to meet the octane spec.
Xylene (and its buddy Toluene) are magnificent gasolines. Toluene is about 114 octane, and xylenes can be anywhere from 115 to 121, depending on the makeup of the different isomers.

Both are very high energy fuels.

(Don't confuse octane with energy potential, we mix in a lot of Butane/Propane into the gasoline because it is cheap and has a nice 94 octane, but it is an awful fuel, not dense, no oomph, results in a poor 'drivability' index, another spec we have to meet.)

You can read in various Formula 1 articles of a time when teams ran 80% toluene mixes, until that was banned.

Xylenes have lots of uses outside gasoline, as you know we can sell it for lots o'cash as paint thinner/solvent, and toluene is also worth plenty - we make it into Styrene plastic and ship it to Japan and the USA. We don't like to have to put it into the gasoline. But gas pays the bills, so if a blend comes up short on octane, in goes just enough 'X&T' to get them out of the jam.

I can assure you that one or two gallons of xylene (or toluene) to nine of good quality pump gas will do wonderful things for your power, from an octane and from an overall power point of view. Trust me, you will not get anything like it from an oil company - most 'race gas' still has Lead additives to boost the octane, not X&T.

It is also relatively simple to work out your final octane in your tank - just add the octane of the pump gas and the octane of the X/T. So 8 gals of 94 octane and 1 of 114 octane = 866, divide by 9 = 96.2 ( if there is no Lead involved, it screws up the result)
It is best to keep it less than 40% of the total, because you are also diluting the other additives, the detergents/anti-static/stability package.

And never believe the crap on the "Octane Booster" bottle - 'adds 2 to 4 octane points' - they mean points as in "point one of an octane" 12 ounces to ten gallons may make 0.1 difference (very expensively!)

**this link may have some repeated info**
http://www.elektro.com/~audi/audi/toluene.html