I've been reading a bit on WI and have only seen info on not having to retard timing and reducing the chance of detonation. Would keeping those timing values be the only way to make more power on a VF22 pushing 19-20 psi already? Would running WI enable the VF22 to push more psi or is the size of the exhaust housing the limiting factor?

It's no different than any other tuning. You're still trying to find the best balance of fuel, timing, and boost for your given hardware. There's nothing stopping you from running more boost on pump fuel without WI, you'd just need to run richer AFRs.

Maybe I should phrase my question differently.

Obviously there is a limit on the amount of air the 2.0L can push through the exhaust housing of the VF22. Can that limit be reached on pump gas? If not, would WI be able to push the 2.0L to that limit?

Not sure where you're going with that. Through the exhaust housing? I think the cold side is a bigger limitation than the relativeely large P20 housing. If I understand what you're asking, the answer is yes, you can explore the relatively meager flow limits of the VF22 on pump fuel (which will be somewhere around 18-19psi @ 7000rpm on a 2L - ~500cfm). That certainly doesn't mean you can explore the horsepower limits.

I have heard an current indepth discussion on the waterinjectioninfo/phpBB2 forum that you can extend the turbo operating range by a great amount by injecting water before turbo.

Here is the link:
http://www.aquamist.co.uk/phpBB2/viewtopic.php?t=267

Warning - highly technical.

On a 2.0 liter motor, 20psi is nowhere near the limit of the vf22. However, it IS near or beyond how far you can boost with that turbo on 93 octane pump gas. If you run WI, you should be able to get 21-23psi pretty easily. You will likely have to spring the wastegate to hold it steady. You will also be able to run more timing at a given boost-pressure without knock.

I would probably avoid pre-turbo water injection. Post turbo will have more than enough charge-cooling and octane-boosting effect to let you run it to 12.5:1 or 13.0:1 on 93 octane, AND run more timing and boost. Some people swear that pre-turbo water injection is groovy, some people say no-go. NOBODY says post-turbo water injection is a problem for your turbo.

Remember, after you get richer than about 13.5:1 on gasoline, you're just wasting fuel as in-cylinder coolant. And fuel is a lousy coolant.

I've seen a dyno with the 18G on 93 octane at 309 AWHP and 365 AWHP on C16. Can similiar results be obtained with water or water/alcohol injection and 93 octane as obtained with C16?

18G>VF 22

Yea, the 18G is better in that it costs more to achieve the same results.. NASIOC logic ;) :p


Back on topic, no, you should not count on WI giving you the same results as C16. Perhaps in a very well tuned, muli-port injected setup, it could be possible.

Yea, the 18G is better in that it costs more to achieve the same results.. NASIOC logic ;) :p


Back on topic, no, you should not count on WI giving you the same results as C16. Perhaps in a very well tuned, muli-port injected setup, it could be possible.

Well, the 18G spools quicker and has more top end, but it does cost more.

93 octance with water or water/alcohol injection would be like what level of octane?

Here's a thread you should visit: http://www.aquamist.co.uk/phpBB2/viewtopic.php?t=457&postdays=0&postorder=asc&start=0

When tuning for water injection not only is more timing desireable and available, but it's necessary to keep from losing power. Don't let that scare you away, it WILL allow more power, but it slows down the flame development angle. The Flame Development Angle is NOT related to the rate at which the charge actually burns, known as a Rapid Burn Angle. Think of water injection as "delaying" the ignition of the fuel. You advance timing to compensate for the delay, usually about 5 degrees, but it has no adverse effect on overall cyllinder pressure.

And here's a graph you may find usefull.

x axis = fuel/air ratio (inverse of air/fuel ratio)
y axis = Indicated Mean Effective Pressure (essentially torque)

Red = Straight Fuel
Blue = Water Injection @ 50% constant relative to fuel
Green = Methanol/Water 70/30 Injection @ 50% constant relative to fuel

As you can see, water alone allows about 12% more torque (3-5 more psi), and a mixture of 70% methanol with 30% water allows 60% more torque without detonation.

However it should be noted they were injecting more than three times as much water as is usually injected today. Modern setups are a little different ... but you can still expect significant improvements in power when done correctly.

http://www.imagehdd.com/d1y2004/3187NACA821_Intercooled.jpg

Adrian~

Also note that your typical 11-13:1 AFR's are the WORST for water injection. You can actually run 14.7:1 or leaner without generating any addition knock when done correctly.

There are big differences between Subaru engine's and the engines in that graph, however the point is clear: water injection requires drastically different tuning to straight gasoline.

Think of water injection as "delaying" the ignition of the fuel. You advance timing to compensate for the delay, usually about 5 degrees, but it has no adverse effect on overall cyllinder pressure.

This is true, but a rich mixture also slows burn rate, so unless you leave fueling alone (which you won't), you can't look at it as just the changes from the water. You also have to account for the changes from removing fuel. In practice you cannot apply any standard rules like this, you just have to re-tune.

Also note that your typical 11-13:1 AFR's are the WORST for water injection. You can actually run 14.7:1 or leaner without generating any addition knock when done correctly.

It should be noted that the theoretical case bares little to no resemblance to a real-world case (i.e., a turbocharged subaru engine). Don't go trying to tune your WI'd motor to 14.7 if you want to get good power out of it.

What I was trying to point out with the 5 degrees is the typical amount of advance required when fuelling is constant.

For instance if you take it to someone for tuning they may not wish to advance an additional 5 degrees over what they are "used to" at that particular A/F ratio and boost. It's just meant as a general guidance.

Many tuners are afraid to advance the timing that far beyond what they consider normal, even when you say you are using water injection. This is probably because they do not fully understand what water injection is doing. While both a rich mixture and water injection require more timing, water injection delays the Flame Development Angle, not the Rapid Burn Angle. Because of this the extra advance is not harmful as long as your WI system is well maintained. If you were advancing that much from adding fuel alone you could cause abnormally high cyllinder pressures.

If you are doing the tuning yourself, or you have a good tuner, the tuning process won't be any different ... you'll just end up with a few extra degrees of ignition advance or an extra pound or two of boost when you are finished because that's where the new knock limit will lie.

Adrian~

Most turbo stock engines, especially Subie, pretty much run at near their full capacity by 4000rpm. It would mean that at maximum torque area the engine is receiving more fuel than necessary. As the engine is revved beyond that point, the a/f ratio is getting towards ideal.

Unfortunately at the same time the turbo efficience map and the VE map of the engine is also decreasing, so the engine still run pretty rich.

Once a bigger turbo is installed, you need to either put bigger fuel injectors in or just run water injection to replace the original excess fuel, now used for producing clean power.

It is often claimed by tuners that you need bigger injector because you are "running out of fuel" to get more power - a very mis-leading statement often used. The truth of the matter ism the engine is not running out of fuel for power but excess fuel for cooling.

One should be able to get 400 BHP at 2 litre of fuel per minute, not even have to run lean to achieve that. Regardless of octane (within a few points). I am sure there will be a great deal of disagreement on this claim, especially from tuner that encourage the use of bigger injectors.

In order to extend the limit of the vf22, water injection is the only item needed plus a few pound of boost - leave the ignition timing to the Subie's ECU to dial in the extra timng. There are a few real life proof on this board ove rthe years and it is not an un-proven claim. Leaner and Meaner is the way to go.

That's an interesting theory peter, but I don't think the stock ECU map's fuel and timing curves are anywhere near optimal for a larger turbocharger or water injection. It'll run too rich in the mid range where there's plenty of injector (stock ECU runs low 10.x AFR) and then lean out up top as the injectors go static. It'll also run way too much timing advance up top to account for the tiny stock turbine housing. I would not consider that a good tune for power let alone reliability, even with WI used to keep it from knocking. YMMV, of course. Perhaps with a reflash and careful tuning the stock injectors could be used, but it's always nice to have some headroom. Or perhaps you're talking about a turbocharger that's just slightly larger than stock, not something like a VF22 or bigger.

I'm not sure what stock Subaru turbo hits peak demand around 4000rpm. That's extremely low. Mine achieved the highest MAFS value around 6000rpm. *shrug*

so much info, i think im getting dizzy. My question is, what kind of ECU would be best for this type of setup? Im sure a UTEC can handle it just fine, but could a reflash pull the same thing? im guessing so just as long as the tuner has had experience with WI and knows what he/she is doing.

That's an interesting theory peter, but I don't think the stock ECU map's fuel and timing curves are anywhere near optimal for a larger turbocharger or water injection. It'll run too rich in the mid range where there's plenty of injector (stock ECU runs low 10.x AFR) and then lean out up top as the injectors go static. It'll also run way too much timing advance up top to account for the tiny stock turbine housing. I would not consider that a good tune for power let alone reliability, even with WI used to keep it from knocking. YMMV, of course. Perhaps with a reflash and careful tuning the stock injectors could be used, but it's always nice to have some headroom. Or perhaps you're talking about a turbocharger that's just slightly larger than stock, not something like a VF22 or bigger.

I'm not sure what stock Subaru turbo hits peak demand around 4000rpm. That's extremely low. Mine achieved the highest MAFS value around 6000rpm. *shrug*

I am not sure of the VF22's flow map compared to the stock turbo. Since the engine has two load-sensors, MAF, TAS and MAP, there must be some real-time correction factors - it is like towing heavy load at 5000 feet. For a given conditon, the MAF's signal must be engine's primary input for load. Since I don't know, I could only assume

In your case, wherever the injectors hit peak torque peak, the fuel demand will be greatest - power plus cooling. At 6000 where your MAF received peak reading, but I think the fuel injector has already reached it peak delivery rate well before there.

In order to gain extra power, you need to extend the engine's RPM or at least sustaining the boost pressure without extra heat. The VF22 has the ability to achieve both. My question is, can the stock injector supply enough fuel to keep the a/f ratio between 12.5-13.1 and WI perform the in-cylinder cooling.

Getting way off topic now.. sorry about that..

In your case, wherever the injectors hit peak torque peak, the fuel demand will be greatest - power plus cooling. At 6000 where your MAF received peak reading, but I think the fuel injector has already reached it peak delivery rate well before there.
Assuming you keep a fixed air/fuel ratio throughout (this is a bad assumption, but otherwise the subject is open to much interpretation), the point with the highest fuel demand will be the point at which the most air is being consumed by the engine. The MAFS tells us where that is. With non-flat fuel curves, this may vary.
In order to gain extra power, you need to extend the engine's RPM or at least sustaining the boost pressure without extra heat. The VF22 has the ability to achieve both. My question is, can the stock injector supply enough fuel to keep the a/f ratio between 12.5-13.1 and WI perform the in-cylinder cooling.
I think it could be made to work based on the IDCs I see with larger injectors, but you'd surely be running the injectors static at points in the map and have very little headroom for dense air on extra-cold days.

You are absolutely right, it is best not to assume. We'll try to return to the topic in hand.

I wonder if the car's lambda sensor will be affected by the use of water and alcohol.

If WI makes the lambda read rich, the engine management will automatically reduce fuel and return to rich mixture in the absence of water, then there is no need to put any safe guard on WI systems?

It has not been my experience that adding water has a serious effect on O2 readings. However, even if it did, the ECU does not gather O2 data for fuel trimming within the operating range where WI would be used. Unless you started adding water all the time, even at light throttle (when the ECU does monitor O2 data for fueling), it shouldn't make any difference.

Depending on the amount of water you are injecting, I have seen about a tenth of a point difference between water and no water runs (water shows a tenth point leaner).

To that end I have a lowly VF30. In winter, high atmospheric pressure and -10F will get me running at most 80% IDC on 560 CCm pinks. I don't have any AFRs to go with that, sorry. But I think they were fairly rich (around 12).

A buddy of mine is going to plop WI on his VF22 w/ utec and wideband O2. After we get that done, I can give you info on how TXS tunes his setup with pinks, and then you can extrapolate from there.

It would be nice to know if anyone know about injecting water and alcohol mixture and which way the lambda reading will shift.

Just interestsed if anything else that will affect the car's original a/f (preferrably leaning) when water is injected. Air temnperature? MAF etc.

I know the knock sensor will pick up the absence of knock and automatically advance the ignition. But if the same sensor can do the same for a/f sensor, it will be great. If a humidity sensor and be spliced into the air temperature sensor to simulate a hot chrage conditions, the management will start leaning the a/f ratio? Is just a thought.

I type bad.

It is common for the exhaust to show a leaner condition by about 0.1 AFR. So the lambda reading will shif left, slightly.

I type bad.

It is common for the exhaust to show a leaner condition by about 0.1 AFR. So the lambda reading will shif left, slightly.

Have just stumbled onto this link, water injection seemed to make the lambda read rich- a large swing of over 1 ratio
http://www.aquamist.co.uk/phpBB2/viewtopic.php?t=507

Or was it caused by something else?

Not much info in that post unfortunately, and it seems to contradict common logic on the matter. I wonder if he wasn't injecting a significant percentage of some petroleum distillate that would richen the mixture. The frequent misfires from running that much "water" would also contribute greatly to changes in AFR. So I would not conclude anything from that thread unless the author of that post comes back with significantly more data.

this is getting so invovled...

i'm looking for this to be easier than what it really is... i'm gonna buy an aquamist system, running 18G/fmic/pinks and UTEC, stock internals. i currently run 22psi on 94 octane pump... will i be able to up the boost, or just take more advantage of 22psi w/94 octane with timing advance, etc. Will the pinks now better support this boost level and bring the idc's down a bit, to a more reasonable range?

I'll install it myself, but who should tune it? appears that i clearly would want somebody who's got significant UTEC and WI tuning experience... Maybe i should just bite the bullet and drive the 5hrs to TXS and spend the $$$ to get it done right. I can install stuff, but my tuning knowledge sucks.

how much injection flow do i need, i gather at least 2 'injectors' and something like 6mm each??? or is that too much, too little, etc?

thanks for any more guidance on this topic. i've read around, i know there's a dozen discussions about it, i am just looking for some more specific setup/tuning info on it.

I just found this thread and you guys go indepth so much it gives me a headache. I'm not up on all the tech jargon but I do know what works. I've been running the aquamist 2d system for about a year now, and i'll never run another car without it. I have it set to cut in at 10psi and I swear it feels like a second turbo kicking in, I'm not alone in this feeling 'cause several other people have ridden in the car and at 10 psi their eyes get big and they ask 'what the hell was that'.

RexRonald- I run one 7mm injector for my stage 4 (vf34). AZScoobie or Uncle Scotty or Nathan?(fron turboxs) should be able to point you to a good tuner out your way. My opinion on your injectors is the pinks got to go, you're probably already hitting 100% IDC's at times, I run the modded injectors and have zero problems, plus I'm poor so the price was right!

Aquamist nozzle flow rates: http://www.aquamist.co.uk/sl/plist/pic2/jets/jets.html

It's pretty easy to figure out how much flow you need. Find the max IDCs for your fuel injectors, and then: injector flow * 4 * IDC * .15 (for 15% water/fuel ratio). Keep in mind that you'll be running a lot leaner with the WI, so you'll want to subtract some from your current IDCs. I.e., for me with modified stockers, it works out to about 850 * 4 * .6 * .15 = 306cc/min. It's not an exact science, you just need to get close, in regards to nozzle sizing. With an aquamist setup, the more boost you run the less water you get from the nozzle, so it's wise to err on the side of too much water and then tune it out later if need be.

wrx plus, where did you mount your 7mm injector and how much water/alcohol does it flow when you cut in at 10psi?

RexRonald- I run one 7mm injector for my stage 4 (vf34). AZScoobie or Uncle Scotty or Nathan?(fron turboxs) should be able to point you to a good tuner out your way. My opinion on your injectors is the pinks got to go, you're probably already hitting 100% IDC's at times, I run the modded injectors and have zero problems, plus I'm poor so the price was right!

thanks for more info... pretty much the closest tuners to me are godspeed and paynetechnologies in michigan, i'm in clevelend, they're about a 3hr drive... i am excited to get the water/alcohol injection going for next season... (i store during the winter)... i will do the install during this winter... is the 2d the one that uses the fuel injector amplifier to cycle the high speed sprayer (or whatever its called)???

Also, what % of alcohol to water are you using in your mix? Where are you getting the alcohol from... thought i saw somebody was using De-icer windshield washer fluid? or am i loosing my marbles?

also... i don't get how you tune a utec work correctly with the 10psi onset of the injection... UTEC timing and fueling are dictated to TPS points... So how to do you advance timing and back out fuel right at 10psi in UTEC (to mate up correctly with when you start injecting the alcolhol), when you can really only tell the UTEC to do something specific by TPS points, or am i wrong again? Do you see what i'm asking?? You advance timing and pull fuel at 60% tps, but it takes time to build 10psi when you are driving along at say 10% TPS, then push the pedal to 60% TPS, until you have 10psi on tap, you don't have water being injected... how does this work out? or i guess it doesn't really matter, since i'm gonna pay someone to tune it for me... just curious and always trying to learn a bit more.

i know about the pinks, i'm sure i'm maxxing the hell out of 'em... but i started stage 4 with a top mount and a vf30... that got old and slow, so i'm progressively upgrading, in the wrong order, 18g.... FMIC... have these now... but by this winter's end, plan to have radiator/t-stat upgrade, 2d or 2s aquamist, and get another dyno tune for it.

where did you get the modded stockers from? how did you know their exact flow rate?

thanks again

Aquamist nozzle flow rates: http://www.aquamist.co.uk/sl/plist/pic2/jets/jets.html

It's pretty easy to figure out how much flow you need. Find the max IDCs for your fuel injectors, and then: injector flow * 4 * IDC * .15 (for 15% water/fuel ratio). Keep in mind that you'll be running a lot leaner with the WI, so you'll want to subtract some from your current IDCs. I.e., for me with modified stockers, it works out to about 850 * 4 * .6 * .15 = 306cc/min. It's not an exact science, you just need to get close, in regards to nozzle sizing. With an aquamist setup, the more boost you run the less water you get from the nozzle, so it's wise to err on the side of too much water and then tune it out later if need be.

but that still doesn't answer what mm sizing, and how many nozzles to get... ya know.. or am i missing some important figures that same x number of mm in nozzle size equates to x amount of injection in cc's minute... guess the logicial question is.. what's the flow rate in cc's for every 1mm of nozzle size?

also, thanks for the math... so if i'm currently running maxxing out to 100% IDC on the pinks, i could effectively lower the % to 90% IDC by injecting just about 300 cc/min alcohol-water at assuming your 15% alcohol-water to fuel ratio... So maybe i could squeak by on the pinks, eh? would it be unreasonable to tune to 20% alcohol-water... i thought i read on team NABR forum that WI can be used reasonably up to 25% ratio to make more power... or maybe that did not pertain specficically to our engine... i remember it was just a general write-up on WI...

thanks

There is no "X" amount of flow for nozzle size. The link I gave above tells you how much flow you will get from each available nozzle. Don't worry about the size, just think of that as a part number. If you want 300cc/min of peak water flow, and are using the 5bar pump, you could use two .5mm nozzles to achieve that, since each .5mm nozzle is 150cc/min. Again, I'd suggest using nozzles with static flow a bit higher than you think you'll need, so perhaps a one .5 and one .6, etc.

I suspect you will be able fine with the pinks / 18g setup and WI. Some studies have indicated that in certain conditions, very high ratios of water would be productive (upwards of 60%), however the returns will probably diminish very quickly. 10-20% is common on street cars. If you want, you could always play around with various sizes, but dyno time gets expensive.

also... i don't get how you tune a utec work correctly with the 10psi onset of the injection... UTEC timing and fueling are dictated to TPS points...



No, the timing and fueling maps are based on load and rpm. The boost map is based on tps and rpm.

No, the timing and fueling maps are based on load and rpm. The boost map is based on tps and rpm.

sorry, i would forget that easily (i've only read the damn TXS utec guide 2 or 3 times, and not recently... and i've never done much with the fuel and timing maps... just the boost curve... thus my assumption of TPS equated changes...)

so as i understand this... changing the amount injected, requires swapping for different nozzle sizes, unless you have the top-of-the-line 2s with custom mapping ability, right?

how is the aquamist fuel inj amplifier connected??? splice direct into a fuel injector wire or what???

This is a great discussion but one thing I am unclear about is the tradeoff in performance between denatured alcohol and methanol or other alcohols ? I know methanol has higher energy value but can be much harder on the plumbing.

This is a great discussion but one thing I am unclear about is the tradeoff in performance between denatured alcohol and methanol or other alcohols ? I know methanol has higher energy value but can be much harder on the plumbing.

http://www.leeric.lsu.edu/bgbb/7/ecep/auto/m/m.htm
http://www.eere.energy.gov/biomass/pdfs/30849.pdf
http://www.gnttype.org/techarea/misc/octanebooster.html
http://www.efoa.org/oxygen.html

As I understand it, ethanol (as in denatured alcohol) is less volatile, has the same AKI (if not better), closer stoichiometric AFR to gasoline, and is more readily available to consumers than methanol.

Anyways, the water still blows them both away in terms of latent heat, so use plenty of that :)

what's the flow rate in cc's for every 1mm of nozzle size?


You can't specify a flow rate based only on the nozzle size. You need to know the line pressure and the air pressure the nozzle is spraying into --- this allows you to determine the effective pressure across the nozzle. Then you need to know the rated flow for the nozzle at some pressure. Most are rated at either 40 psi or 100 psi.

The flow rate will vary at the square root of the change in pressure, ie increase the pressure 4x and flow doubles.

Aquamist has a chart for the rated flow of their nozzles when used with their pump, which normally runs near 100 psi. Other industrial nozzle supplies publish charts for their nozzles.


I am unclear about is the tradeoff in performance between denatured alcohol and methanol or other alcohols ?

That is a little bit difficult to specify. For use as an antidetonation injection, methanol and ethanol are essentially identical. If you get good results with one at 50%/50% mix with water you should get almost identical effects with the other at the same mixture. At low < 50% alcohol content in the WI mix you can essentially ignore the alcohol as a fuel component, it simply cancles out energy lost due to the cooling effect of the water as it supresses detonation.

Unfortunately, as you get higher up in the alcohol content and move into more or less pure alcohol injection, things get a bit more complicated. As you move to alcohol injection you need to begin considering the alcohol as a part of the fuel system. Methanol and Ethanol are substantially different in their proper AFR, so you will have different air requirements depending on which alcohol you are using.

When used as a fuel, ethanol is slightly more effecient than methanol, but methanol will allow you to make slightly more power. Unless your running an alcohol fueled race car the difference is probably not important. The AFR for methanol is near 6.45:1, and near 9:1 for ethanol.

Isopropyl alcohol behaves much different as a fuel, and if you change from a WI mix of methanol and water, and go to an Isopropyl and water mix you may have significantly different behavior at the same mixture settings.

The difference is significant enough that in WWII, the aircraft mechanics substituted de-icing alchohol ( isopropyl alcohol) for methanol in WWII fighter aircrafts ADI systems ( the aircraft people call WI Anti Detonation Injection )and the result was blown engines, because the system was calibrated for methanol or ethanol only.

The best bet is to arrive at the best mixture / nozzle size for your setup by experimentation as all your tuning setups will interact.


With cutting edge tuning, WI will allow you to almost double the power output of the engine if your willing to get it properly dialed in. But at that tune level if you lose your WI it means instant piston kit.


Larry

Not much info in that post unfortunately, and it seems to contradict common logic on the matter. I wonder if he wasn't injecting a significant percentage of some petroleum distillate that would richen the mixture. The frequent misfires from running that much "water" would also contribute greatly to changes in AFR. So I would not conclude anything from that thread unless the author of that post comes back with significantly more data.

People are waiting for futher information on that thread.

Frequent mis-fire would cause significant increase in both oxygen and hydrocarbon emission. Since lambda sensor can only detect oxygen, it will show a "lean" reading.

Until we know how the afr was extracted to construct the chart we can't make any assumptions about the "rich". The reading could be taken from a full gas analyser that reads CO concentrations to show the afr.

RexRonald- I got the 2d system because it had all the options that I wanted, including the aquamist race pump that is used in actual race cars because of it's dependability. I started out using windsheild washer fluid because it is premixed and easily obtained, but I switched after the first couple of months to mixing my own from distilled water and methanol. IMO the blue dye was a problem waiting to happen it sticks to everything that it has direct contact with.
The FIA is the heart of the system and mounts inside the car. It is easy to hook-up and mirrors the fuel injector pulse from the #1 cylinder, telling the HSV exactly when to fire your W/I.
I put my kit in before the adapter was thought of, so it is tapped into my APS TMIC right before the throttle body.
Methanol up to 50% is the only alcohol the is safe for the aquamist pump. If you want to use denatured alcohol there is a kit in the vendors forum especially for that. you can get more info for that kit in the alaska forum 'cause they were the testers, since they only get low octain fuel up there.
The 2d system comes with a boost activated switch preset at 10 psi (although you can change it), I would recommend also using the spare sylenoid from the UTEC to turn on the W/I at a certian RPM and keep it on until a certain RPM, this is needed believe me 'cause if you rely on the boost switch and fall below 10psi at high RPMs you will get knock depending on your state of tune.
As for initial tuning, fully install your system and take a drive, you will notice the difference, and it will be completely safe to leave it like that until you get it tuned. Most tuners seem to tune to the edge of safety with the W/I deactivated, and use the W/I as a safety blanket, but it still works wonders like that.
The reason some people use 2 nozzles is to get more flow, but some people will run one very small nozzle before the intercooler and the main nozzle right before the throttle body- the reason for the tiny nozzle before the intercooler is that it almost immeadiatly cools the intercooler and air charge upon activation.

Thanks for the great leads.

If I understand this correctly it sounds like a good strategy is inject ~15% [ of gas flow ] 50-50 mix methanol or denatured alcohol with water starting at about 10 psi . Use one of the aqua-mists that interface to your ECU or standalone.

chucktoo- denatured alcohol cannot be used with the aquamist pump. 15% water to fuel is what in theory should be optimal, but often it is lower than that depending on your set-up, state of tune, local octane rating, etc etc. The aquamist 2d can be used with your stock ECU, or pretty much any aftermarket EM, which system is best for you will depend on your set-up and what you expect of it. As for the % of methanol to use, start with 20%, it's usually enough.

Thanks for the input - now I have an idea of what to do next . 20% methanol is great - .2 x .15 = .03 so 5 gals of methanol is good for 166 gal of gas at boost - this will last a while . Do you have any idea at what temperature it freezes ? I am in the Boston area.

This sounds like a winning path to me unless there is something I don't understand.

Time to start gathering parts

Now where to put the tank in a Wagon.

Found the answer 20% is fine unless it gets really cold then go 30% .

http://www.ashchem.com/adc/chemicals/faq_answer.asp?typeID=3&is_header=N the answser 20% is great unless it get really cold .


:)

thanks,

thats good to know about the methanol-only for the aquamist... now, where do i get methanol? am i able to just go somewhere local (hardware store, etc) and find methanol? how much does it cost on average?

yeah 2d looks about right for me... i really want to push the car for some good power increases... 292 whp at 19psi fp18g currently (dynapack), i want to break well into the 300 range, but don't want to deal with race gas... so WI is the apparent answer. Safe to assume that adding the 20% methanol will tune for more power than straight 100% water?... why else use it i guess.

Do you need to use something like purified or distalled water, or just any tap water will do? any reason i can't use my windshield washer tub for a container?

and what type of material needs to be used in terms of tubing/hosing, that will stand up to methanol over the course of time? specific inner diameter needs?

someone (not me thats for sure) needs to make an all-inclusive FAQ on WI maybe... anyone, anyone, bueller, Unabomber? hint hint


thanks everybody for the great input... this thread is beginning to get nicely informative.

You should use distilled water to avoid building up crap in the WI system plumbing.

I don't think you're going to find a real significant power difference between pure water and water/alcohol. The nice thing about alcohol is it's combustable, so it gives you a lot more gray area around getting the water flow perfectly tuned. Many people use nitrile (Buna-N) hose for this, it has desirable properties. Do not use silicone.

There are lots of good FAQs on the Aquamist forums: http://www.aquamist.co.uk/phpBB2/

I ordered my first 5 gal from each of these guys here .

http://www.kemcooil.com/products.php?cId=2

http://www.hiperfuels.com/index.cgi?PageToView=catalog&Department=81051&Cartid=400481099874807&Merchant=highfuelsn&ExpandedDepts=

Remember 5 gal should do 150 gal of gas under boost - so it is really not that expensive . 55 gal is a lot cheaper but I don't have room.

thanks for the links... that should do the trick!

This is where I go (http://www.worldwideracingfuels.com/catalog_c30755.html), but then again, I just drive down there and don't have to worry about the shippmg costs.

Additionally, I have it from good authority (Brad Shaffner) that the Aquamist pump can fall behind on water supply on 0.8 mm jets and larger. Above that use an acumulator or an in-line pump to prime/feed the aquamist.