Ok, so I was watching my laptop as I was driving home today and i am getting constant spark retard any time i touch the gas ... not only when I get any knock (false knock). For example, 5% throttle at 70mph i have .1 or .2 degrees of spark retard. 40-50% throttle at 70mph around 4-5 degrees of spark retard. There is a linear (or close enough to it) relationship between the two examples.

I am running 11.5:1 compression with 91 octane and one bottle of octane booster. The only thing I can think is that the octane isn't enough, and the computer is sensing this and retarding the spark. Any ideas?

I did notice after a 2.5 hour drive when I came to an intersection and it idled it was missing a little bit. This got better as I started driving more around the city.

Now that I'm back in Texas, I'll have 93 to put in her so that will be a real test (tomorrow when I fill up).


[Modified by Glock'94, 10:25 PM 4/25/2002]


[Modified by Glock'94, 10:25 PM 4/25/2002]

 

ttt

 

How's that 93 doing? 11.5 & 91 seems on the line.

 

I just filled up about 2 miles from home, so I'm not sure if I got any of the 93 in yet or not. It didn't seem to be missing as much. Hopefully that's all it was. I'm going to go out with my laptop and do some readings after I'm done working on an infrastructure project.

You ever use Visio Scorp?

 

I made a diagram of the entire bunker here and our computer systems with it.

 

:cool: I've used it WAY too much this semester. I have probably 100mb worth of diagrams :( ERD's, CLD's, DFD's etc....

 

Well, i'm happy to say that all my spark retard is gone now that I have 93 octane in there. It's amazing what computer technology in our cars does. I could definitely feel more power in the car (and i should have with 4* more of advance!). Needless to say .. i think from now on while in Oklahoma I'm going to have to put some Toulen in my tank with the 91. I don't like running with spark retard. There is too much of a chance the computer won't retard it and i'll get detonation at the wrong time.


[Modified by Glock'94, 1:07 AM 4/27/2002]

 

if you cut the gas with about 15% toulene you'll get 93-94 octane, xylene is even better i use it

btw 30% xylene will give you 100 octane

 

Where do you get Xylene? I have 1 gallon of toulene

 

same place you buy toulene

I get mine at home depot, right beside the toulene, they have other chemicals you can try too but xylene is pretty much the best at 117 octane
theres some other options..check this out, be aware all this stuff is bad for rubber lines, dont leave it sitting in your fuel system for long periods, the best choice is proper 94 gas, but these can be good boosters for racing.


Formula #1 - Toluene
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 Toluene. 12-16 ounces will only raise octane 2-3 *points*, i.e. from 92 to 92.3. Usually mixed with Toluene 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 toluene 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", combine 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.

Sample Mixture
To make your own octane booster, it is easiest to make up a large batch, and then bottle it up in "dosage-size" uses.
Below is the basic formula of one of the popular octane booster products. To make eight 16 ounce bottles (128 oz = 1 gal):

100 oz of toluene for octane boost
25 oz of mineral spirits (cleaning agent)
3 oz of transmission fluid (lubricating agent)
This product is advertised as "octane booster with cleaning agent *and* lubricating agent!". Diesel fuel or kerosene can be substituted for mineral spirits and light turbine oil can be substituted for transmission fluid. Color can be added with petroleum dyes.




[Modified by nsimmons, 12:59 AM 4/27/2002]

 

HMmmmm This sounds interesting. What are the drawbacks if any? Does it affect injectors, cats, pump etc?


[Modified by 90_roadster, 7:29 PM 4/27/2002]

 

It's bad for any rubber lines in your fuel system (including washers). Also, if you mix it at too high of a concentration, you might eat away at the linings of the tanks and gas lines.

 

Maybe I'll turn the ricer down the street on to this then. Buwahahahaha