Editor's
Note :I've
reproduced this information verbatim as requested by the author.
However, some external links may have been changed. If you know
where these documents can be found, please let me know. Thanks Background I started experimenting with octane boosting by first adding small doses of over the counter octane boosters and noticed immediate improvement. The engine ran smoother and quieter, was more willing to rev and had noticeably sharper throttle response. The octane shortage was confirmed by the sticker on the filler cap that stated that 93 octane fuel was needed. Since the highest octane rated fuel that was commonly available in Washington state is 92, I decided to investigate long term cost effective octane boosting so that I could fully enjoy the performance that this car offered. My other car at the time, a 1990 Audi V8 quattro had an even more dramatic response to octane boosting. I managed to convince a few good friends to try it and the reaction was overwhelmingly positive. When I attempted a broader based dissemination of this exciting find, I was greeted largely by broad unyielding skepticism and plenty of FUD (fear, uncertainty, doubt) regarding toxicity, safety and engine damage. There arose a need to more clearly explain the details of octane boosting, hence giving rise to this article. Q: Will my
car benefit from octane boosting? Modern vehicles now use computerized engine management systems that can react to engine knock and retard ignition timing if low octane fuel is being used. Consequently cars are now being manufactured with very high compression ratios that appear to give good fuel economy and at the same time good performance. This combination does assume that fuel of adequate octane is being used. Q: Why bother
to boost octane at all since my engine can run just fine on lower
octane fuel? For turbocharged or supercharged engines, insufficient octane will also lead the engine management system to curtail the amount of boost which in turn defeats the purpose of these engines. Q: How did
you discover using toluene? A motorsports journalist, Ian Bamsey, was able to obtain Honda's cooperation for his book "McLaren Honda Turbo, a Technical Appraisal". The book documents the key role that the toluene fuel played in allowing these tiny engines to run so much turbo boost without detonation. The term "rocket fuel" originated from the Formula 1 fraternity as an affectionate nickname to describe its devastating potency. Thus I concluded that I should focus my research on using toluene for my octane boosting project. Individuals with good long term memory will recall that when unleaded gasoline was first introduced, only low octane grades were available. While it is not entirely clear that high octane super unleaded gas came about as a result of the advances in fuel technology in Formula 1, there is every reason to suspect that this is indeed the case, since many of the major oil companies were involved in the escalating race to develop increasingly potent racing fuel during this era. Q: Why do you think
toluene is better than other types of octane boosters? Mindful of the evil reputation of octane boosters in general, toluene is a very safe choice because it is one of the main octane boosters used by oil companies in producing ordinary gasoline of all grades. Thus if toluene is indeed harmful to your engine as feared, your engine would have disintegrated long, long ago since ordinary pump gasoline can contain as much as 50% aromatic hydrocarbons. Toluene is a pure hydrocarbon (C7H8). i.e. it contains only hydrogen and carbon atoms. It belongs to a particular category of hydrocarbons called aromatic hydrocarbons. Complete combustion of toluene yields CO2 and H2O. This fact ensures that the entire emission control system such as the catalyst and oxygen sensor of your car is unaffected. There are no metallic compounds (lead, magnesium etc), no nitro compounds and no oxygen atoms in toluene. It is made up of exactly the same ingredients as ordinary gasoline. In fact it is one of the main ingredients of gasoline. Toluene has a RON octane rating of 121 and a MON rating of 107, leading to a (R+M)/2 rating of 114. (R+M)/2 is how ordinary fuels are rated in the US. Note that toluene has a sensitivity rating of 121-107=14. This compares favorably with alcohols which have sensitivities in the 20-30 range. The more sensitive a fuel is the more its performance degrades under load. Toluene's low sensitivity means that it is an excellent fuel for a heavily loaded engine. Toluene is denser than ordinary gasoline (0.87 g/mL vs. 0.72-0.74) and contains more energy per unit volume. Thus combustion of toluene leads to more energy being liberated and thus more power generated. This is in contrast to oxygenated octane boosters like ethanol or MTBE which contain less energy per unit volume compared to gasoline. The higher heating value of toluene also means that the exhaust gases contain more kinetic energy, which in turn means that there is more energy to drive turbocharger vanes. In practical terms this is experienced as a faster onset of turbo boost. Chevron's published composition of 100 octane aviation fuel shows that toluene comprises up to 14% alone and is the predominant aromatic hydrocarbon. Unfortunately composition specifications for automotive gasoline is harder to pin down due to constantly changing requirements. Chevron's web site also describes the problems of ethanol being used in gasoline. MTBE was heavily touted as a clean additive several years ago, and became a key ingredient in reformulated gasoline that is sold in California. But recently new studies arose that showed that MTBE was far more toxic than previously imagined. Organizations such as oxybusters have formed around the country to eliminate the use of MTBE in gasoline and several states, including California have passed new laws to eventually outlaw MTBE. Q: How much
toluene should I use per tank of gas? (14.6 * 92) + (1 * 114) / 15.6 = 93.4 The Audi A4 1.8T is a good example of a car that has very high octane needs if it has been modified to produce more turbo boost. The base compression ratio of this car is a very high 9.5:1 and when an additional 1 bar (14.7 psi) of turbo boost is applied on top of it, the resulting effective compression ratio is way beyond what 92 or 93 octane fuel can ever hope to cope with. Most modified 1.8Ts running without octane enhancement are running with severely retarded ignition timing and boost. Q: Will toluene
damage my engine or other parts of my car? Even in the unlikely event that the 92 octane gas has a aromatic content of 45% the resulting mix would still be within the bounds of gasoline sold in other countries. Q: Isn't toluene
an extremely toxic substance?
Note that the ATSDR also
rates gasoline
as a hazardous substance. Mobil's spec sheet for toluene even goes as far as saying that "Based on available toxicological information, it has been determined that this product poses no significant health risk when used and handled properly." Q: Isn't toluene
an active ingredient of TNT (trinitrotoluene) and is thus deadly? Q: How much
does toluene cost, and where can I buy some? Q: Can I just
dump in 100% toluene into the tank like the F1 racers?
vroom vroom vroom Because toluene is such an effective anti knock fuel it also means that it is more difficult to ignite at low temperatures. The Formula 1 cars that ran on 84% toluene needed to have hot radiator air diverted to heat its fuel tank to 70C to assist its vaporization. Thus too strong a concentration of toluene will lead to poor cold start and running characteristics. I recommend that the concentration of toluene used to not exceed what the engine is capable of utilizing. i.e. Experiment with small increases in concentration until you can no longer detect an improvement. Q: Why not
simply use racing gasoline or aviation fuel? A2: Racing gasoline could be a much more convenient way to run high octane fuel compared to having to constantly mix in toluene with each fill up. There are, however a few caveats:
Q: Ok, what
is the catch? Q: What safety
measures can you recommend in handling toluene? Q: Do you
have testimonies of others who have tried this?
I didn't get to drive the car until PIR the next morning, (my GF doesn't like the 200; it's too big) but the report was that there was no change for a mile or so, and then all of a sudden, the engine seemed to smooth out and became quite eager to rev and run. Well, by that calculation, I only managed to bump the octane to just shy of 93, but it seemed to make a big difference. I ran the car hard all day, (for reference, it's got an '87 MC turbo motor, K26, 12psi boost, and currently no intercooler) and even at 12 pounds of boost, I never once felt the ECU backing the timing off. Granted, the ambient temps never got above 50, and my water and oil temps were rock solid. (Oil just pushing above 100C) The only cars that I had
to get out of the way for was an Integra Type R and a couple
of race-prepped P-cars. I even managed to lap the NSX once! It
was a really good day! <grin> Okay, kids, gather round. This is important: we spend lots of money for our car, lot of money modifying and taking care of it, lots of effort and pride in owning it. So if someone comes along and proposes to give you something that would increase your enjoyment in driving by exponential measures and it would only cost you two or three bucks per tank of gas, would you be suspicious like the 100MPG carburetors? Would you listen long enough to real-life testimonies to consider this improvement for yourself? Well, this is the case for Toluene and what it can do for your V8Q if you been using anything less than 92+ octane. Get some.Try it. No harm, no risk. Use about 24-32 ounces per 1/2 to full tank. You will not look debonair. You will have to suspend your "cool" look. You may want to try this alone. YOU WILL HAVE THE SHITTEST, MOST PLASTER, GRIN ON YOUR FACE YOU HAVE EVER HAD! It won't come off. You'll tell the kids, daddy has his own "transformer". It will be like a new car...no, better than new! I took my family out to
dinner tonight and could hardly keep from dropping it into manual
and showing off like some teenager (I don't think my 17 year
old daughter was inpressed). I wanna see some posts here with
personal experiences by you guys using this stuff - I wanna know
that my car is normal and hasn't been deprived ever since I've
owned it. I did the Rocket Fuel thing tonight on my Extremely Modified 5KCSTQ that runs 24 PSI of boost... And I can tell you not only does my ears and my butt say that the Rocket fuel is doing it's job but My ECU Data logger that gives me the timing value for all 5 cyls says it's working too. Before Rocket Fuel I was
running full retard (14 Deg of timing) on boost and would still
on occasion get some knock, now I'm getting timing numbers around
22 Deg's with ZERO knock ever. I'm running 2 Gallons of Toluene
7oz of ATF and 17.5 gals of 93 oct gas for a net octane of 95.15.
I'm next going to try 3 Gallons of Toluene (96.23 Octane) to
see what timing numbers I get. After being convinced that my car was running below it potential - Owners manual recommends octane rating between 95 and 99, although it_will_run on octane as low as 91 - I stopped by Sherwin Williams and picked up a gallon. It was on sale for $5.85! Anyway, head to the chevron and pour a half gallon into the tank before pumping in the premium. The car took 16 gallons so there was still 4 gallons in the tank. I take off....nothing (obviously burning the fuel still in the lines). About 10 miles later, HOLY SH*****T!!!!!!!!!! It really does everything advertised by the list. It is so much more responsive from a stop and low speed, it really is impressive. I would agree with the sentiment that it feels like a totally different car. For the non believers, you really should try to get some higher octane fuel in your tank, whether through the use of Toluene or not. The owners manual recommends 95 to 99 octane** for optimal performance. With the half gallon of Toluene I added to the 92 octane, I was only running at approximately 92.6 octane and the difference was simply amazing! If you haven't tried it, do yourself a favor and give it a whirl - I swear you'll be impressed. (**note: this person confused RON octane mentioned in the
owners manual with R+M/2 octane that is sold in the pump. 95-99
RON is roughly equivalent to 91-94 R+M/2) After trying rocket fuel for two weeks, I can only say I love it. The first tank, however, was a disappointment. I think I did not add enough of rocket fuel for the first tank. So I added a little more for my second tank, it ran better but not too much improvement. Then on my 3rd tank, what a difference, the car feels like a "Rocket" now, even though it is an "Auto". I always feel there is more power available for me. I think for my 1st and 2nd tank, I did not have enough rocket fuel in it, even though I added one gallon per tank. Then, on my 3rd tank, I had enough because of the left overs from my 1st and 2nd tank. (I fill up my tank at about the 1/4 mark). Now I only have about 2 gallons of rocket fuel left, I better get more now!!! :-) Reference materials: 2. McLaren Honda Turbo - a technical
appraisal 3. Chevron's excellent Motor
Gasolines Technical Review |