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So I've been looking at using water injection for some time now for cooling. I don't want to install a FMIC and I see the water injection as an answer.

So the current situation as it stands is this - I picked up a pump from a friend for dirt cheap, might as well stole it. The pump is a 806-052 from ELR which best I can tell is made for Aquamist. It is a 100psi pump. My car is currently running on stock injectors, a SAAB TMIC, and around 10 psi on the VF11. Where I want my car, for right now, is to run around 14-15 psi on the VF11 and leave my injectors alone.

Clearly the first question is will the stock injectors support that?

I know that 14-15 psi is outside the VF11 efficiency range and hence I got the water inject pump.

So, how do I control it? Because I'm not wanting to use the system for tuning - right now - I don't see the need for a progressive controller. I'm currently thinking that if I get a boost activated switch such as - http://www.innovativetuning.com/catalog ... ts_id=2837 - that I could set that for 8 psi and let it rip. Will this be too 'rough'? I'd prefere to keep it cheap for right now until I upgrade the driveline, turbo, injectors, etc.

The next question then, is what size injector do I need? The pump did come with one but I'm unsure of it's size and it's been sitting around for quite a while in the shop so I'm hesitant to trust it too much for fear it's half clogged.

Then I need to decide if I want to keep my TMIC. I have been playing in autocross - what a hoot!! - and I've got a temp sensor in the engine compartment and I do see the temps hit 140-150*F. This is before the heat of summer really hits. I also see these temps in slow stop and go traffic. This concerns me and is why I have boost set at 10 psi. I'm thinking with the water injection I should be okay. But in the winter when temps don't get over 20*F in the day time, water injection is not really needed. Will my TMIC be too large of a constrictor and just get rid of it during the summer, maybe install again in the winter and turn off the water injection?

Finally, and this is an important one, I need a schematic for the pump. I have four wires total, two clearly are power for the pump and the other two are for the trigger. The power is pretty easy, red and green. The trigger I'm a little less certain on, do I need to feed it a signal voltage, if so how much? I'll keep digging on Google for this one, but if anyone can jump in it'd be great.

I've done a fair bit of reading on the BBS on this, but most of it is general 'Is Meth/Water for Me' type posts which is very informative. But I can't find much on specific setups.

Any help is appreciated and feel free to make any general comments as well.

Thank you.

Could you just give it power and short the other two wires together to see if a closed circuit triggers the pump?

You could try cleaning the injector with degreaser. I'd keep the intercooler, maybe instal the injector upstream of it so that the two cooling devices work together.

I'm hesitant to just start playing with wires, this pump retails around $600....

The degreaser is a good idea. I'll probably still set it up as a test with the nozzle spraying into the shop just to see.

And with regards to the intercooler, I'm thinking the same thing right now. But how at what point am I wasting water to cool the intercooler instead of the air? I suppose I could set up a intercooler sprayer, but then am I really gaining anything?

I would think you'd be cooling the air initially and then increasing the efficiency of the intercooler with any water that isn't absorbed by the air. What would work the best? I think you'd have to experiment and measure your temp changes.

I've never injected just water into any of my cars, but I have injected 50/50 water/methanol or -20* windshield washer fluid into the motors with good results (& i've been spraying alky into one of the cars since '05) - but both of my cars are intercooled (TMIC or FMIC).

Once you figure out the wiring for the pump you'll need to get a jet - I had good results with a cooling mist M5 jet & 100 psi pump & a pressure switch (I'd probably have the system activate once you hit 1/2 of your boost target 15psi = 7.5ish psi activation) so the pump is not on every time you touch the gas.

Innovative Tuning did what you describe on their SS + VF39 @ 20psi no intercooler, on stock injectors - ? nozzle/nozzles they used on that set-up......

I think you'll have good results with your system if you set it up properly.

http://bbs.legacycentral.org/viewtopic. ... +injection

see the above link for some more info

Awesome, thank you for the post. I was hoping you and Innovative would jump in. I've been following your work, and theirs, for a while now as I don't want to go FMIC unless I absolutely have to.

I've done a bit of reading on Nabisco, but I don't really trust their advice like I do here.

Sounds like I'll probably ditch the TMIC and just go with the alky/water for cooling. I have a different idea when it comes time to do the turbo and injectors. I don't mind doing some tunning using the alky injection but I'd prefere to have most of my fueling needs addressed with the injectors and gasoline.

Thanks again.

so heres my question, where should the nozzle go?
i've read many articles saying you should NEVER inject water or anything before the intercooler but they give no reason why. other articles state that its ok.
if i install the nozzle after the intercooler (06 wrx tmic) then my intake temp sensor won't be accurate because it'll be too close right? ( just a few inches away) so should i install the temp sensor after the throttle body and put the injector in its old place? i really don't like the idea of drilling a hole in a major part of the engine...
i would rather install the injector before the intercooler if possible i just don't want any problems...
i will be using a mix of methanol and water ( no more than 50/50, possibly less methanol with a 3 gph nozzle and will be running 14-15 psi boost all on stock injectors)

thanx
-Alex

Too bad they don't list a reason not to put it before the intercooler - I'm curious to know the reason.

yeah it puzzles me since it seems to be the perfect place...
anyone? what about the people using water injection do you use it after the intercooler or before?

oh and where the $%#@ do i get methanol?

thanks
-Alex

Methonal is a bit corrosive so after time it will slowly eat away your intercooler. How much... I don't know, but that's the theory for injecting after the intercooler.

I thought you should not put the nozzle before the I/C because as it passes through the I/C the super fine mist will collect on the I/C internals turning into big drops - puddles.

I inject right @ the t-body & although the inside on the I/C + T-body look a little chalky (dry meth) it has held up fine for 3 years of daily use - any way you cut it meth will go into the I/C & engine for that matter...

I read that meth mixed with water (even as little as 1% water) is much less corrosive than straight meth (? 1 reason for the recommended 50/50 mix).

I tried a 70:30 meth:h20 mix on the Starlet & it ran good holding nice EGTs for the burnout/pass.

Same car same with a 50:50 meth:h20 mix @ the same boost levels became violent - literally lifting the drivers side front wheel on the engagement of 2nd gear!

Adding water to methanol definitely reduces it's corrosiveness.

I think the biggy to not put the nozzle before the intercooler is because the water mist will condense into larger droplets and be much less effective.

Couldn't the extra heat at the point before the intercooler cause the droplets to be absorbed quicker or would the greater density prior to introduction to the larger volume of the intercooler be too detrimental to absorption? Wish I knew fluid dynamics more as I find this fascinating.

You can get methanol pretty easily

- Windshield washer fluid is usually meth+water (some brands use antifreeze but will say ethyl-gly... on the back of the bottle) -20* fluid works good, -30* fluid works about as good as 50:50 meth:h20
Look for methyl alcohol & water as ingredients & the little flammable warning.

- Race shops that sell canned 5gal jug of race fuel (like c16) usually have jugs of methanol - I got a 5 gallon jug of VP M1 from a shop like this

- Drag-Race tracks usually have Methanol available for cars that run this fuel


Back to one of the original posters questions if you already have a TMIC I'd use that + alky all year round - thats what I do.
OBS-T = TMIC+alky, SS = FMIC+alky (again!) (I admit we do not usually see -20* in NYC).
If you do not have a TMIC I'd see what alky can do on its own as the TMIC will act as a interwarmer in traffic.

evolutionmovement wrote:Couldn't the extra heat at the point before the intercooler cause the droplets to be absorbed quicker or would the greater density prior to introduction to the larger volume of the intercooler be too detrimental to absorption? Wish I knew fluid dynamics more as I find this fascinating.

I don't know if that's an easy question to answer. I think both of those items may play into it, but the fact you still are going through a restrictive volume with surface area.....I just don't see your atomization of the meth to be that good.

What is the boiling point of methanol? Then the next question is, same question, but at a 50/50 mix of meth & water.

I think Josh may be heading down this road, but one of the big issues I would see with injecting prior/after the intercooler would be how much of the mixture truly evaporates before hitting the engine. When it's injected it's a fine mist, but it's still in liquid form. Your charge cooling come from evaporating the small drops. Obvouisly not all of the mist will evaporate, or I would assume it wouldn't, so that line of thinking makes me believe it would be better to inject before the intercooler.

But then that arguement may change depending on if you using the system solely for cooling or if you're using it for fueling as well where you need to make sure everything is getting into the chamber at the flows you are expecting.

Really though, I'm seeing the TMIC as just a restriction. If the water/meth will cool the air to where the intake manifold is cool to the touch as Innovative has said in their posts, then there is not need for the TMIC.

I have also found that the intake & TMIC end tank is cool to the touch on the OBS-T after WOT runs from 1st thru 4th - never checked the SS's charge pipe or manifold for coolness after a run.

I'm running windshield waster fluid at -30 or -40 when I can find it. This drops my intake temps from over 180F to around 160F without intercooler.

+1 on the water injection AFTER the intercooler. The water/alky only provides cooling as it is evaporating. You also want the un-evaporated mist to enter the combustion chamber to help with further cooling of the internal parts, slow the burn rate, and clean carbon off the internal parts. Big droplets (that will form inside of the intercooler if you spray upstream of intercooler) will only disturb the normal combustion process and possibly cause micro fractures on the surface of metal parts, since the large droplets will only get moving when the engine is at full song.