toddk911

"The only downside to burning these as a substitute or addative to gasoline"

Toulene IS the basis of gasoline from my understanding. They simply "water it down" to bring the octane levels down. Running Toulene/Xylene is about as close to "pure gasoline" as you can get.

"Despite an earlier claim, gasoline IS NOT mostly aromatic hydrocarbons. Last I read the limit was something like 20% in most states. " Correct. Once they "water it down" the levels are about 20%. But before they get their hands on it, gasoline is mostly aeromatic hydrocarbon.

Running alcahol (100-105 octane) ??? and IIRC, you can only run about 10-15% to be safe. So that does not allow you to mix with 93 and get much of an octane gain.

I think MTBE is your best bet for performance, but not practicality. As I believe MTBE actually has a higher kilocalorie potential then any of the others, plus the higher octane.

Xylene - 117 octane. Any questions???

Cheapest (for the long run) and most practical = water/alch or propane injection.

silverbullet

I've heard some people saying that xylene and other octane boosters can get past the pistons and into the oil, thus thinning it down. This doesn't seem possiple to me since 1. the gas/xylene is burning right away, and 2. you are not running rich enough for any gas to be wasted.

So I imagine that this is completely not an issue.

Does anyone know if the SFR or Lindsey fuel lines will hold up to the xylene?

951_RS

Yes they will.
Ignore most of the blah blah blah talk on here lol...

The threads basis was about toulene (now xylene also.)
Not about alchohol injection etc. or what's better...

Just do your math right and remember you probably have more gas in it then you think so in a matter like this where you can't monitor everything, overcompensate and be on the safe side. Just don't drink it

toddk911

If your fuel lines hold up to fuel, they will hold up to Toulene/Xylene.

"Ignore most of the blah blah blah talk on here " I agree

Porsche-O-Phile

Has anyone done a methanol conversion (or ethanol) for the 951? I'd be curious to see the results from this. 80% is a good start, but what kind of numbers do you get? How expensive is eth/meth per gallon? Are there issues with high alcohol based fuels eating rubber lines or deteriorating injectors (my understanding is regular gasolines help lubricate pumps and rejuvinate seals; alcohol will do nothing to assist in this). What other provisions would be necessary?

formerGMguy

In response to the earlier suggestion of using Acetone, I'd stay away from it. Its an extremely simple molecule and only contains 3 Carbon Carbon bonds. Even with a low physical density the energy per unit volume is low. Acetone is also a keytone and under incomplete combusiton it would be possible to partially oxidize and create acetic acid (vinegar). It also happens to be a great solvent for many plastics, you'd be much better off with alcohols.

And as for fuel lines holding up to high Toluene/Xylene content....Just because your lines hold up to gasoline doesn't mean that it will hold up to the aromatics well. Chemical structures of the two are very differant in general. Aromatic compounds tend to be much better solvents of polymerized materials due to their planar make up as opposed to a highly brached chain molecule. The action of the branched molecules is akin to stabbing someone with an egg whisp compared to a knife (i.e the aromatics).

I hadn't even considered running alcohols with an open loop oxygen sensor system. Good point.

ehall

"http://www.faqs.org/faqs/autos/gasoline-faq/part1/

http://www.faqs.org/faqs/autos/gasoline-faq/part1/"

The chemist who chimed in here provided the above links. Thses are really worth reading. There are a number of posts in this thread that can be cleared up and.or refuted by reading the entirety of what's in the links.
BTW as an aside one might wish to balance the validity of a post by an actual chemist vs the posts of "enthusiasts". I'm an enthusiast myself, so I'm not trying to throw stones.

BC

I think this is an important issue.

What about fuel additives for people who use thier cars for...20,000 miles a year? I mean how much are you using your car Special? Bill says 1500 miles. I couldn't imagine using my car that little if it was ready to drive.

I did the toluene thing - HUGE hassle, and it gave me serious headaches when I had to poor it in the tank. I suppose easier would be getting a 50gallon drum and pumping it in every week, but that sounds dangerous.

Bill

BrendanC,

First question you should ask yourself is "do I need more octane"? If you are running high boost like I am the answer should be "yes". If you are running stock boost levels, high octane is just a waste of money.

As with any modification (which changes in fuel apply), go with what makes sence to your needs. If using "T" is a hassle, buy 100 octain pump fuel. Both work. If you rely on your car for daily use, want the car to run trouble free mileage, maybe it would make sence to run stock boost and 92 octane. There is no one simple answer for everyone.

And the miles per year has no implication on fuel, with the exception - if you are detonating your car will last fewer miles.

try holding your breath when filling. J/K.

951_RS

high boost is not the only thing, but also advanced timing, however in the 944t world, I'm not seeing anything really about tuning timing, which to me is an uncomplete tune... I get crap excuses about how the stock computer does a fine job, but that doesn't satisfy me because every car is different and especially when you go to bigger turbos, new injectors, etc.

That's OT though.

ehall

It's very much on topic. It's the ability to turn up the boost without knock AND seriously advance the timing safely that allows 533 hp in a 2.5 turbo, as we have seen.

951_RS

Lol, no I meant what I said was off topic about how I dont see enough people tuning timing on 951's. Yes what you said was on topic.

ehall

most people don't have the tuning knowledge or ability to make the most of the technology available, regardless of fuel. That's what I was kind of saying.

dlr944

formerGMguy - can you be more definitive about wheather or not the stock fuel lines are capable of using aromatics? If not, what fuel lines (available for the 951) are more suitable for using aromatics?

Appreciate your thoughts.

BC

With 91 in CA, and the gas basically getting crappier every year, it is a major concern for people running boost in any motor. Especially more then OEM boost, or boost where there wasn't any before (me)