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Discussion Starter #1
It's been brought up before in private. It's been whispered about in back rooms by shady individuals too embarassed to say in public that they have run paint thinner in their gas!

Toluene is a pure aromatic hydrocarbon, already in your gasoline, has an RON of 121 MON of 107 and wait for it ... waaaait for it ... it's cheaper than octane boost OR race fuel!!


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

This would be a life saver for those turbo guys having detonation issues under extreme heat and/or load conditions! Towing a trailor in warm weather? Running hard in a hot dyno room? Going to the track on an unusually warm day? Up your octane and spare your engine!

Yours Truly,
Dubbya

p.s. Many thanks to Vigge for initially bringing toluene to my attention and causing me to do a little researching! Can't wait to try it. Will of course report back when I do. (Though it's cold enough this time of year that I'm not in a hurry.)
 

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Hi Adrian,

Here something for you to look at since you became interested on the topic on Tolune.

Octane:
Toluene 114
Xylene 120

Source: most paint stores

These two hydrocarbons are aromatics and are a significant portion of normal pump gas. (25 - 45 %)

A while ago there was a post asking about using toluene injection. This would create on boost enrichment and enhance the octane of the AF mixture. This would require an auxilary fuel tank, pump, pipes, FPR and controls. This would work, so would bigger injectors. Only a few application would merit entertainment of that idea.

There are posts on the net concerning adding these to pump gast to get improved octane and power. Some claims are for greatly improved power. In these cases the subject vehicles were getting higher boost and the ECU and knock control functions had been holding things back becuase of lack of sufficient octane in pump gas.

Octane averaging calculations:

C = tank capacity
X = volume of octane enhancer to add
Op = octane of pump gas
Oa = octane of addative
Ot = octane target

( (C-X)xOp + XxOa ) /C = Ot

moving the terms around yields:

X = Cx(Ot-Op) / (Oa - Op)

for 92 octane pump gas, a target of 94 octane, a 50:50 mix of toluene and zylene for a Oa of 117 and a 17 gallon tank

X = 17X(94-92) / 117-92 = 1.36

So for 1 17 gallon tank, adding a 1.36 gallon 50:50 mix of toluene and xylene will produce an estimated octane of 94. The concentration of 1.36:17 is not very high! Obviously adding any oil as a lubricant is not warranted for low concentrations.

You can see why those weeny cans of octane increaser in the store shelf are ineffective. When those state that they increase octane by 4 points, they are talking about 4 10ths of of one octane level. They really don't explain that to they? And those off the shelf addatives can contain oxygenates and ?MBTE? that fake out trionic systems that use spark plug knock sensing and you may actually get less power and boost!

You will probably end up spending $15 for that increase of two octane numbers. You cannot afford to do this as a permanent solution to any problem.

What could you expect to gain? By increasing the octane you can evaluate if there are any improvements with higher octane or problems that go away. Spending $20 on these addatives is certainly a definative way of making such an evaluation. Compare this cost to shop time at the dealer to chase down a vague running problem. Compare to a large bottle of Techron Concentrate at $10. Certainly one should first use Tecchron Concentrate to deal with any acquired octane demand from deposits and such.

With a Trionic system you probably are not going to see massive increases in boost and power as these are already limited by the ECU. But hesistation, bogging down, a loss of boost or perhaps things like a part throttle increasing power over that of full throttle may respond to higher octane. If they do not, you can conclude that such problems are not octane related or not responsive to the octane increase that you created.

If an octane fortified tank of fuel does produce some obvious running benefits, I don't see a good permanent solution other that water/alchohol injection.

For those at lower altitudes, 93 and 94 octane fuels are available. For those in California or higher altitudes, many turbo applications can suffer. With the Trionics, the boost target against the absolute pressure sensor reading. And with the 9-5 Aero, and Viggen as well as boost modified systems, there may not be any pump gas available that will allow things to run as they should. So there is a good method to evaluate if higher octane will improve things.

I am not suggesting that everyone should do this. But a few will, and if they post their observations, we can all learn by that.

Text by Dean Smart[/b]
 

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Discussion Starter #3
Well I HAVE tried race gas recently. HUGE improvement in warm weather! 70 degrees and it ran full boost all the time. Beautiful! But that stuff is WAY more expensive than Toluene considering that Toluene is 114 M+R/2 and street legal race gas is only 100 (race gas: $7.00/gal, Toluene: ~$4.00/gal), and I only really *need* it for track days, and perhaps any warm weather dyno visits. Water injection is next on the slate for a more permanent solution once money is saved up.

Note: Do not run race gas with iridium spark plugs. For whatever reason, they don't like eachother. Problems only arise however, when driven hard. They seem to be ok at first, then at some point Trionic decides that it's not happy and sets itself permanently at base boost. Can't explain it! Put the platinums back in again, and voila' problem solved. I think boost builds slower with the platinums for some reason. It would build much faster with the Ir, but then go straight to base boost.
 

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Originally posted by Adrian W:
[qb]Do not run race gas with iridium spark plugs.  For whatever reason, they don't like eachother.  Problems only arise however, when driven hard.  They seem to be ok at first, then at some point Trionic decides that it's not happy and sets itself permanently at base boost.         Can't explain it!  Put the platinums back in again, and voila' problem solved.  I think boost builds slower with the platinums for some reason.  It would build much faster with the Ir, but then go straight to base boost. [/qb][/b]
What gap are you running on those plugs. I know saab recommends 1.0-1.1mm for the Gap. A common belief is that gap should be reduced as boost goes up.
I run my modded viggen with 0.8mm gap (BCR8ES9).
 

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Discussion Starter #5
That's the trouble with Iridiums! You can't *safely* gap them because of how fragile the very small center electrode is. Same with Platinum, though I've seen it done sucessfully.

I think the trouble with re-gapping and/or electrode diameter changes has to do with the way the IGS system works. It's based significantly on the volume of the cyllinder created between the electrode edges at the gap.

[ electrode gap X (electrode radius)^2 X pi ]

Changing the dimensions effects (at least slightly) how it reacts. However the Iridium plugs seemed to have a chemical reaction. They're closer to the stock plugs than any of the standard plugs out there in terms of dimension. They're even very similar design wise, and are made by the same manufacturer, but they just didn't get along with the race gas. Work great on 91 octane! Just not 100 ...

I look forward to WI, and perhaps this summer when the sea level drag strip opens up I'll be able to get some appropriate (for my power anyway) time slips! The last time slips were at high altitude, in warm weather, and not on full boost! (because of the heat) I really can't wait to see what it will do with some Toluene.

____________________________

BEWARE! IGS works in part of the NOX content of your combustion gasses!! If you put in too much Toluene these levels will drop significantly! This is because Toluene does not contain any Nitrogen! Just be forewarned! Even as much as 25% should be ok, but don't get any ideas about running on pure Toluene!
_____________________________

Your engine does have a backup knock sensor to the IGS, but it's best not to force it to use it!

Cheers,
Dubbya

edited for spelling
 

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Originally posted by Adrian W:
[qb]____________________________

BEWARE!  IGS works in part of the NOX content of your combustion gasses!!  If you put in too much Toluene these levels will drop significantly!  This is because Toluene does not contain any Nitrogen!  Just be forewarned!  Even as much as 25% should be ok, but don't get any ideas about running on pure Toluene!  
_____________________________

[/qb][/b]
About 25% or slightly less seem to be the most common rate over here. I personally have not tried on my car, but my friends run it in theirs when on strip and dyno (TT supras, skyline aso). When on strip you can usually run more boost without the risk of knock when toluene is in the picture. The trouble with saab is that you cant really **** in a manual boost controller to add max boost. So the gain is proportional when more boost cant be added.

I quess the best solution would be to get an ECU with a "strip" software. This could be mapped so that I will give you more boost than regular gas can handle.
 

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Discussion Starter #7
True Vigge. But race gas does not lower your EGT nearly as much as water injection, and combining too much boost with a stock Saab is not a good idea. On a Viggen you might get away with it because of the Nimonic alloy exhaust valves and stock mandrel bent exhaust. But I wouldn't reccomend it for most of the older ones.

As for me? Even right now with the temp at 18 degrees C my car will not run full boost. California gas really is pants!

I don't *need* better gas, but I'd like to see numbers at the drag strip more proportional to a car that has 213 whp. Toluene oughtta help out with that!

Cheers,
Dubbya (aka PhD Evil ... Dr. Evil's cousin who was too cheap to go to Evil medical school.)
 

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Originally posted by Adrian W:
[qb]True Vigge.  But race gas does not lower your EGT nearly as much as water injection, and combining too much boost with a stock Saab is not a good idea.  On a Viggen you might get away with it because of the Nimonic alloy exhaust valves and stock mandrel bent exhaust.  But I wouldn't reccomend it for most of the older ones.  

[/qb][/b]
And what comes to the stock viggen IC, simply it sucs! Here is some test results from the Swedish boys.

Test car
9-5 Aero M/02
Outside temp +1.0 C
Up to operatin temp by driving 80-90 km/h.
Slow down to 1500 rpm in 3:rd gear, fullgas to 6100 rpm, change to 4:th, fullgas to 5600 rpm. After this manifold temp +40 C vid 5600 rpm in 4:th gear. In other word 39 C ower outside temp.

One can only imagine, what the temps are in modded viggens and aeros with original IC.
Soon I'll get a better IC.
 

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Originally posted by Adrian W:
[qb]"One can only imagine, what the temps are in modded viggens and aeros with original IC.
Soon I'll get a better IC." --- Vigge

Sounds awfully familliar ...

Intercoolers Thread

Bigger IC or Larger T thread

Finally some evidence to back up things I've been saying for ages!      

Yours,
Dubbya [/qb][/b]
Here are some more fiqures from Nordic tuning dyno.

We tested it on a 9-5 aero (modified).
With stock intercooler was it 92degres
inlet tempreture in 6000rpm.
With the intercooler (this is with nordic cooler for 9-3 and 9-5) was it 41 with full boost and 6000rpm.
 
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