Home-Made Race gas? Options

[mark95turbo]

I was looking around on DSMtuners.com and found a few articles on making home-made 116 octane race gas. It seems that if you mix 1 part toluene(industrial cleaner) to 9 parts 91 octane gasoline it will yield a 116 octane mix. I was wondering if anybody had tried this? I was thinking about testing it out for the 30th.


Heres one of the articles. There are a few more, but this one seems to be the best.
http://www.dsmtuners.com/forums/showthread.php?t=96893

[awdnot2]

I think TurboTension has had some sucess with this.

[mark95turbo]

After I get the TSi back together im gonna run a tank full of this and see how she does. I'll post my results. Hopefully I can get some logging done before and afterwards.

[ICGerms]

Actually, going by R+M/2 for octane rating, a 10% toluene mix will only yield slightly higher than 94 octane, but that's starting with 92 octane unleaded, not 93. This is a good article that I found a while ago...

http://www.elektro.com/~audi/audi/toluene.html

[awd4me]

i've got some formulas that ill try to dig up later that i learned in school....tolulene or xylene is what i've heard...

[mark95turbo]

Great link ICGerms!

[MidwestDSM]

I think TurboTension was running xylene last year...

[ICGerms]

Great link ICGerms!

Yeah, I actually found quite a bit of info. on raising your octane level. Now, the question that I have is: Does higher octane actually increase HP (I doubt it), or does it simply allow you to run higher boost w/o knocking (more likely)? I believe that it has more to do with the latter, however, some people have said (guys in Australia, I think) that there was a noticeable gain from running higher octane. Maybe they were getting timing retard from knock w/the lower octane and this diminished once they increased the octane of their fuel...I don't know. Anyway, I have decided to just mix 99 octane with my normal 93 octane on race days...I'm not getting any significant knock at 22psi, but a little higher octane certainly can't hurt.

[natedogg]

Your suspicions are correct, ICGerms. I run 100 octane in my Talon. This allows me to run much higher boost levels than I would be able to run on regular pump gas. I am currently running 26 psi on my BR500 with no knock whatsoever and 25 to 27 degrees of timing advance.

Higher octane fuels actually burn slower than lower octane. This allows higher compression (such as that dynamically provided by turbos or superchargers) because the fuel will burn slower and not detonate or pre-ignite before normal combustion even in very hot, high compression situations. In other words, it waits for the spark rather than ignite on a hot spot (such as a valve edge, casting imperfection, or ring landing) in the combustion chamber. There are other situations that cause pre-ignition and/or detonation as well such as overly hot intake air charges due to an ineffecient turbo or insufficient intercooling, but higher octane helps defeat all of these.

[mark95turbo]

That article also said that the higher octane burns hotter which can cause quicker turbo spool by the kenetic energy caused by the hotter combusion. I'm not sure how much spool difference this makes for our normally daily driven cars at relatively low boost levels (compared to 20PSI and up track monsters), but squeezing everything out of these cars is what owning a DSM is all about.