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Discussion Starter #1 (Edited)
I am looking for some real-world experience on this topic in Supras, (not looking to hear from the #nevermeth crowd, but thx).

Details: So far, it appears I am avoiding timing pull up to 21 psi with meth on 91 octane just as well as running 105 oct. But I am ready to start nudging the boost towards a goal of 24 - 25psi. I will keep monitoring for timing pull, but wondering if other meth-inject guys think 91+meth can truly deliver the detonation-prevention of 104 oct at these higher boost levels?

If I just can't run that much boost on 91+meth, I guess I'll have to save the 25 psi for the rare splurge on race gas.

Setup is hybrid twins, stock ECU, safc.
 

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Spraying 50/50, 22 psi was my limit before significant timing pull. Honestly, I was always apprehensive wondering if there was an even spread between cylinders and of a system failure at 22. Eventually I quit using it. I'm running E85 now since it's readily available here in Colorado, however, it was very expensive to convert.
 

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I've basically maxed out timing on 50/50 at 27 PSI on a 74 mm turbo and 93 octane, on the dyno.
 

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Correct me if I'm wrong but isn't meth kits primary use to be a cooling agent/aid not an octane booster? I know gus use it for lower psi range.
 

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You can use it to supplement actual methanol, which is higher octane. Just use larger nozzles and replace the 93 octane going into the cylinder.

Or, as you say, use it for lower boost and higher timing.

The issues are tuning and if something goes wrong, it's going to hurt the engine.

If you do a lot of brake boosting or hot lap the car, I'd let it cool off between runs if on supplemental fuel injection. Heat from the manifold, intercooler, etc. will reduce the cooling ability before it goes into the cylinder.
 

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Discussion Starter #6
I am not using it to add fuel, ie not tuning for the added octane/fuel of methanol. I am using it 50/50 water to cool charge air and prevent detonation, so more as an alternative to high octane.

So far, looks like 400hptt's experience is an example for me to save the high-boost action for race gas only, while 220's experience was maybe I can make 25 psi work without race gas.

220, you must have been on stand-alone-EMS, right? When you say "maxed out timing" do you mean had it every bit as advanced as the stock ECU tries to do?
 

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Some people say you shouldn't exceed 25psi (not sure why) on meth but I have seen supras on here running (I think) 31 psi. I'm planning to run 25psi.

Meth reminds me a lot of the mentality of nitrous. Those without any real experience try to scare you away but those with experience are all for it as long as it's used properly.

Without a doubt it does deliver a safe octane to do so, my only concern with your setup is the stock ecu. With an aftermarket unit you could perhaps have it adjust boost or retard timing in the event it detects knock at x value and set it at a lower threshold or something. With the stock one obviously you can't.
 

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I used 50/50 meth injection last year and ran 27 psi regularly. Only issue I had was trusting the system. Car ran great but was always looking at the meth flow gauge etc.

I converted to E85 and so glad I did.. I will never use meth again. Rather stay at 18 psi on pump and run E85 once in a while then drive around worried sick my motor is gonna blow up.

Ryan
 

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Use a quality kit such as alkycontrol or aquamist. Do not use aem or snow. If you're looking for cooling qualities use 50/50 mix of vp m1 and water. I run straight m1 @ 25psi safely with room for more. I'm only held back by my current injectors.

Meth is great for cooling and supplementing octane. No reason to use race gas unless you're running super high boost when you can use premium plus meth or e85. However, the conversion to e85 is expensive. If you ever wanted to run even higher octane, all you'd have to do is run race gas and meth.

To avoid uneven distribution to the cylinders, use 3 to 5 tiny jets vs 1 or 2 large ones for better atomization, and run them at the intercooler so that the charge is saturated by the time it goes into the manifold.
 

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I used 50/50 meth injection last year and ran 27 psi regularly. Only issue I had was trusting the system. Car ran great but was always looking at the meth flow gauge etc.

I converted to E85 and so glad I did.. I will never use meth again. Rather stay at 18 psi on pump and run E85 once in a while then drive around worried sick my motor is gonna blow up.

Ryan
This hits the nail on the head....Meth/water WORKS but you are constantly worried about the setup. I had a direct port setup that I ran for years but swapped to E85 as well. I even went to a single fuel pump setup to get rid of concern of a single pump dropping out.

I wouldn't hesitate to use water/meth as an additional aid in a car not being pushed to hard.....but relying on it while tuning on the edge gets to be more worry than it is worth.
 

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I am going to be subjective on this, since that is the true way of life.

I do not think it is a good idea to use meth as a substitute for octane.
The only thing I would run the meth for, is to cool down charge air temperatures.
But I would not turn my boost up or really change anything tune-wise. If the system fails, the car is still running at 100%
Think of it like dumping ice in the intercooler, but much more efficient.

Agree with Ryan as well. It seems as though (IMO) that many spend more time thinking about the system failing rather than enjoying the car.
Which is not surprising when people run 2x the recommended boost with windshield washer fluid coursing through the intake
 

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I also ran 28psi on 50/50 water/meth. and 14gph injector IIRC

I had a fail safe through AEM EMS, so wasnt that worried. When the pressure switch activated, it activated the Nitrous map with the extra timing. Ran around 8 degrees more than with regular 94 octane. Switched to E85 when it came available.
 

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Water injection serves 2 closely related functions on a turbo engined
car. Firstly it cools the charge air temperature by utilising an effect
known as the latent heat of evaporation. This property can be self
demonstrated very easily. If you pour something that evaporates quickly
like petrol on your hand it feels very cold. This is the rapidly
vaporising spirit removing heat from your skin and bloodstream by the
aforementioned process. By spraying a very finely atomised mist of water
into the inlet of a turbo engine when under boost conditions the
evaporation of the water into steam causes a temperature reduction in the air and
fuel intake charge. A cold charge is less likely to be subject to
detonation than a hot charge. A cool charge is also denser, able to
carry more air and fuel mix per unit of volume. These 2 properties of
water injection allow either less chance of detonation at a given boost,
maybe allowing lower octane fuel to be used, or to allow a rise in boost
pressure usage without detonation. These are very desirable goals for
any modifier of a turbo engine, or one using an engine mapped to run
on a higher octane fuel than generally available in the US. Japanese
import turbo cars for example.

People ask whether squirting water into an engine causes corrosion. In
fact this is not a problem, the combustion temperatures under boost
ensure the water is turned instantly to steam and is ejected out of the
exhaust. The water mist is injected only when high boost is sensed via
a supplied pressure sensor switch. The basic combustion process of
hydrocarbon fuels causes LOTS of water to be generated anyway, which is why cars
not driven on regular long journeys will rust out a mild steel exhaust
system from the INSIDE out. If water is added in the correct volume, via
the supplied, calibrated jets, this is not a problem.

Even when used alongside a larger or more efficient intercooler, or
indeed when an intercooler is used in an application where one was not
present as standard, water injection can and does increase charge cooling
still further. Water can be stored either in the existing windscreen
washer bottle or in a separate, dedicated, container. In cold conditions
it is essential to add an anti freeze additive to the water to stop pump
damage through freezing. Windscreen washer additive serves this purpose
fine and the engine won't mind ingesting this solution at all. Or you
can add neat methanol, which is usually the anti freeze additive in
washer fluid anyway. Using a 50 / 50 percent by volume water / methanol
mix will actually help increase the octane of the intake charge, as an
added benefit. As a yet further advantage the latent heat of evaporation
of methanol is extremely high. A win / win situation. It is not however
obligatory to use methanol as an additive. All components of the water
injection kit that are in contact with the fluid are stainless steel or
able to tolerate water and methanol or screen washer additive without
degradation. A properly set up system does not use a vast amount of
water, in fact a modern car sized screen washer bottle used also for the
water injection reservoir will suffice admirably. A water filter is
included to keep any sludge out of the pump or jet. This should be
checked regularly for contamination and blown out if residue is
apparent within.

A more technical explanation:

Let us take a quick look at ignition. Those who have a Heywood can look it up
- mines on loan so going by memory. The first thing that happens is a plasma
cloud is formed by the arc consisting of super heated electron stripped atoms.
When this cloud "explodes" a ball of high energy particles is shot outward.

The highest energy particles are the hydrogen atoms - and they penetrate the
charge about 5 times as far as the rest of the particles. As they lose energy
and return to normal temps - about 5000 k - they begin to react chemically
with any surrounding fuel and oxygen particles. The effectiveness of spark
ignition is directly related to the availability of free hydrogen. Molecules
containing tightly bound hydrogen such as methanol, nitromethane, and methane
are far more difficult to ignite than those with less bonds.

During combustion - water - H2O ( present and formed ) is extremely active in
the oxidation of the hydrocarbon. The predominate reaction is the following:

OH + H ==> H2O
H2O + O ==> H2O2
H2O2 ==> OH + OH
Loop to top and repeat.

The OH radical is the most effective at stripping hydrogen from the HC
molecule in most ranges of combustion temperature.

Another predominate process is the HOO radical. It is more active at lower
temperatures and is competitive with the H2O2 at higher temps.

OO + H ==> HOO
HOO + H ==> H2O2
H2O2 ==> OH + OH

This mechanism is very active at both stripping hydrogen from the HC and for
getting O2 into usable combustion reactions.

Next consider the combustion of CO. Virtually no C ==> CO2. Its a two step
process. C+O ==> CO. CO virtually drops out of early mid combustion as the O
H reactions are significantly faster and effectively compete for the available
oxygen.

Then consider that pure CO and pure O2 burns very slowly if at all. Virtually
the only mechanism to complete the oxidization ( Glassman - Combustion Third
Edition ) of CO ==> CO2 is the "water method".

CO + OH ==> CO2 + H
H + OH ==> H20
H2O + O ==> H2O2
H2O2 ==> OH + OH
goto to top and repeat.

This simple reaction accounts for 99% + of the conversion of CO to CO2. It is
important in that fully two thirds of the energy of carbon combustion is
released in the CO ==> CO2 process and that this process occurs slow and late
in the combustion of the fuel. Excess water can and does speed this
conversion - by actively entering into the conversion process thru the above
mechanism.

The peak flame temperature is determined by three factors alone - the energy
present and released, the total atomic mass, and the atomic ratio - commonly
called CHON for Carbon, Hydrogen, Oxygen, and Nitrogen. The chemical
reactions in combustion leading to peak temperature are supremely indifferent
to pressure. The temperatures and rates of normal IC combustion are
sufficient to cause most of the fuel and water present to be dissociated and
enter into the flame.

As can be seen above, water is most definitily not only not inert but is a
very active and important player in the combustion of hydrocarbon fuel.
Ricardo and others have documented that under certain conditions ( normally
supercharged ) water can replace fuel up to about 50% and develop the same
power output, or that the power output can be increased by up to 50% addition
of water. This conditions were investigated by NACA and others for piston
aircraft engines. It is important to note that these improvements came at the
upper end of the power range where sufficient fuel and air was available to
have an excess of energy that could not be converted to usable pressure in a
timely manner.

As a side note - Volvo recently released some SAE papers documenting the use
of cooled EGR to both reduce detonation and return to a stoic mixture under
boost in the 15 psi range - while maintaining approximately the same power
output. Notice - they reduced fuel and still get the same power output.

When you consider that EGR consists primarily of nitrogen, CO2, and water ( to
the tune of about two gallons formed from each gallon of water burned ), you
might draw the conclusion that it also was not "inert". They peaked their
tests at about 18% cooled EGR - which would work out to about 36% water
injection and got about the same results under similar conditions that the
early NACA research got.
 

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For all those saying its dangerous, there is nothing to worry about when running meth so long as you have the right setup.

There is no failsafe for the system per se, but there is a way to ensure that the motor isn't destroyed. Aem "failsafes" are bullshit.

What you need is a quality meth system and a very competent tuner. You need to have multiple tunes on a standalone and have a manually setup failsafe that will detect a failure of the meth system and automatically switch to a pump gas tune. That's what I have.

Anything is possible when enough thought and effort is put into it. Imo, meth is easier, cheaper, and more convenient than e85 as an alternative to race fuel if done properly.

There is no out of the box solution. You need a tuner that is good with wiring, trip/pressure sensors and switches to manually build you a failsafe that will run from your meth kit's brain and pump to your standalone.
 

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I'll never use it again. Was on a Stinger 4424.
 

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1. AEM kits are just as good as anything else out there. Been reliable to me for over 8 years and counting...
2. I'm running 93oct and ~70meth/30water, making great power and making it reliable at 30psi here in NJ. No easy access to E85.

Although, I run an AEM ecu and reduce my timing more than most folk to achieve it, needs a very precise tune since I am on the edge and can tell by slight knock activity. My fuel map is a bit different than others due to the onset of extra meth at full boost. I don't have any special safe switches.

One thing I wouldn't recommend is running high boost with the stock ECU (with or without the meth), mainly because it will demand quite a bit of timing out of the engine to start, and that could hurt the advantages you would get with additional boost+meth.
 

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I personally ran into a problem early on when I first started using the system and thinking it was straying since the light came on, but the meth water never went down. Turned out the line lost its prime due to under tightened fitting. Air got in the system and was unable to push past the output check valve. It has been several months, and My meth injection system is working great.

While I am still in a very safe zone, I do agree with everyone that there is a fear that the system would fail you somehow. I check my tank every time now just to make sure it is going, and perhaps I should look into a flow sensor and tap into my emb to remove the MAF clamp when not flowing. Maybe you can have a failsafe system like that before going max boost.
 

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AEM kits are just as good as anything else out there. Been reliable to me for over 8 years and counting...
It may have worked for you over the past 8 years, and that's great, but it is not just as good as anything else out there. The aem kit to alkycontrol/aquamist, is autozone to HKS.
 

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It may have worked for you over the past 8 years, and that's great, but it is not just as good as anything else out there. The aem kit to alkycontrol/aquamist, is autozone to HKS.
To each his own, but the kit works just as well as anything out there with regards to features, reliability, and safety mechanisms. Any of these kits have a tendency to fail. Quite frankly, I can't find a kit that has NOT had a few failures. Tell me specifically why you do not think it is "not just as good as anything else out there"?
 

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It may have worked for you over the past 8 years, and that's great, but it is not just as good as anything else out there. The aem kit to alkycontrol/aquamist, is autozone to HKS.
Have you used both the AEM and Aquamist on your own car for an extended length of time? If not, you're not contributing here.

I trust people with a LOT of experience with the AEM who are responsible enough to know what the fuck they're doing, while also loving their Supras - dre, agm, and Nick 95 6sp - they all have AEM and speak highly about it. While you say AEM is "autozone" and the failsafe is "bullshit," it sounds like you have zero actual experience with it. I used to be a die-hard Aquamist fan, but after helping a friend install an AEM on his 2g GSX and seeing what happens when a 50/50 water/meth injection pops off during peak torque on a pretty "on-edge" pump gas tune, I'm comfortable in saying the AEM failsafe is not bullshit. It saved his motor as he had the failsafe immediately dump boost and retard timing. When he went to a 2.3L stroker, the pistons and bearings showed no signs of damage.

That line pop-off was due to highway tire debris from a line he left hanging and he's now got that covered up, so even that wasn't a flaw in the AEM product. As for the Aquamist - he took that one out because the flow sensor kept melting repeatedly, and it was only in the engine bay on the intake / cool side of the engine. Sorry, but that's not "HKS." I'm still debating between AEM and Aquamist as there are pros and cons to both, but I see it more of a Greddy vs HKS decision than eBay/Autozone. They're both good, but neither are perfect.
 
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