banflu

Hi again everyone,

Some of you may remember my last post regarding knock (https://www.s2ki.com/s2000/topic/844...#entry20321378)

To recap, I live in Malta and I have a 1999 JDM S2000 with Mugen ECU, Mugen cooling mods, Mugen exhaust and Spoon throttle body.
In Malta there is only one type of petrol/gas fuel available. It should be 95 RON but in reality its probably closer to 92 RON (87 AKI)

My S, being JDM, has a compression ratio of 11.7 .. and added to the advanced timing of the Mugen ECU, resulted in "low speed knock" on multiple occassions.
For example, going uphill at 2-3000 rpm .. more than 50% throttle results in audible knocking.

I've been experimenting with octane boosters, and have found that TORCO accelerator works fine, BUT ... it contains MMT. And I've found out that MMT will foul the plugs and is not recommended, especially for a street car.

Someone on the board recommended Toluene - I managed to find a chemical supply store locally and bought some.
After some experimenting with it, I can confirm that when using toluene, mixed with our fuel at around 25%, knocking is reduced by a great margin. I did some "acid tests" I like to call them ... using WOT on steep uphills in higher-than-usual gears (2 to 3,000 rpm) .. with no audible knock whatsoever.
So, I am very pleased with toluene

The only problem I see is this -- a lot of websites say that you should add some cleaning agents and lubricating agents when using more than 20% toluene.
They recommend "mineral sprits" (or DIESEL) as cleaning agents, and Marvel mystery oil (or ATF) as lubricating agents.

Well ... I dont know what mineral spirits are ... and I really dont trust the contents of local diesel fuel .. so I didnt add any cleaning agents.
But I did add 150ml of ATF Dexron 2 with every 5 litres of toluene used.

I am now thinking of using 2-cycle oil instead of ATF, as this was specifically designed to lubricate the upper cylinder parts ... but will it also help to keep the rubber seals etc from drying?
Also .. what can I use as cleaning agents? A friend of mine said that I shouldnt use diesel because diesel has sulpher, and the molecules of sulpher can bond with those of toluene and create "solids" ... I have no idea in chemistry so I dont know what he's on about

Any help would be appreciated !! Thanks in advance

zeroptzero

go to bobistheoilguy.com and sign up as a member for their forums. There is a forum dedicated to fuel additives and general car maintenance. There are some chemical experts on the forums from the oil and gas industry and many other industries, I think you could get some very good advice over there, it's a great forum for oil and fuel related matters.

Sideways

I ran a Mugen ECU for a few years and 94 or 95 octane was adequate to quiet up the ping when not pushing it. I would think a couple liters of toluene to the tank would take care of your needs and not push the lubrication ability of your petrol.

IMHO, just keep it under 20% and don't put those other products in your fuel. Much less hassle and expense.

I also suggest you have the factory ecu near by for when you don't have toluene available. It only takes a moment to switch out.

banflu

Thanks for the replies boyz. I just registered at bob is the oil guy .. waiting for my account to be verified ...

@sideways: I am currently using a mixture of 25%, but next time I am planning to use 30% .. because on one occasion I heard one instance of knock ..
I would like to see if it goes away completely if I use the "maximum" mixture of 30%.
And I really do not want to use 30% toluene with no other additives .. it just wouldn't feel right after all that I've read on the subject.

I would live without the cleaning agents, but it seems that the lube is needed to keep all the rubber parts from drying, to properly lube the fuel pump, and to avoid upper cylinder wear .. as, Toluene is quite a harsh solvent.

Funny you should mention the stock ECU. I did use it for about a week, because at one point I was fed up of experementing with octane boosters etc etc ..
So for the first time, I ran it with straight pump gas and used the stock ECU ... after a day or two, the timing was so retarted that there was MAJOR hesitation, and MAJOR flat spots all over the place. Whenever I used WOT the car would immediately "bog down", and then start to pick up slowly ... then vtec kicks in .. flat spot at 7,000 rpm ... some power .. flat spot at 8,000 rpm .. etc etc etc !
This is what actually led to some major research on toluene ... and luckily I found a local place that sells it

so .. no more OEM for me, it just doesnt work with our local fuel.

xveganxcowboyx

Is there any possibility of buying high octane fuel at a race track? It seems like you are mixing a lot of chemicals in the hope that everything does what it is supposed to. It would seem simpler to find one thing (such as race gas) to mix in and raise your octane instead of several.

Also, what about the possibility of water or alcohol injection? A lot of turbo guys use windshield wiper fluid to keep knock down. It's cheap and readily available.

banflu

I did look into mixing race gas with pump gas, but with local prices it is definitely not worth it.
unleaded petrol sells for 1.38 euro per litre ... sunoco racing fuel (109 octane) sells for around 4.50 per litre !!!
to get a good octane rating i would need to mix at least 40% sunoco.

so, it makes much more sense to buy toluene @ around 2.50 per litre (114 octane) and mix it in 30% concentrations ..
the cost of throwing in ~300 - 400 ml of ATF / 2-cycle oil in every tankful is negligible .. only costs around 1.50 euro



re water / alcohol injection .. i've seen this mentioned in some forums but I cant understand how it works or what its used for ... what is it exactly?
a mixture of water and alcohol is injected in the intake manifold? I believe I read that it doesnt get mixed correctly with the air/fuel mixture ..
and it is sprayed continuously or at certain revs only?
Somehow I think that using a higher-octane gas (however it is derived) is safer for the engine ...

xveganxcowboyx

The cost makes sense on high octane fuel. It is less expensive here compared to standard gas.

Water/alcohol injection is pretty much how you described it. The liquid is injected in to the intake track and mixes with the air and fuel entering your engine. It can be setup to do so on a switch, throttle position, boost pressure, etc...depending on your needs. The combustion temperature is decreased quite a bit. I'm not sure how much of this is due to displacement of air (similar to an EGR valve) and how much is due to the alcohol's cooler burn. I'm sure the water itself absorbs a lot of heat as it vaporizes. Alcohol is best, but the standard blue windshield washer fluid works pretty well and as I mentioned before it is very cheap. You get an added benefit of keeping your engine clean.

There are several manufacturers of quality kits. The Snow kits seem pretty popular.

FAQ

Maybe the right kit?

Supra-holic

I've used toluene in my Supra, only added Mystery Oil. Didn't know the cleaning agents were needed.

Didn't do it much because it was a pain to work with. If I was in your shoes, I would be sourcing a OEM ECU that can retard the timing to eliminate the knock.

drmthtr59

I have used toluene on my KA-T 240sx. I used pure toluene since I work at a chemical analysis company and I am also a chemist. My 240SX ran great at 9psi for 3 years with multiple autox and track events. I've since sold the car and I have yet to try it on my S. Will let you know how it turns out.

banflu

So as a chemist, do you think you can determine if using 2-cycle oil is better than ATF? Will it help in not drying out the rubber parts? Is my mixing ratio of 150ml to 5 lt toluene correct?

I find it strange that you used straight toluene in your car. I understand that straight toluene will make the engine impossible to start when cold.. Unless you were pre heating your fuel?