I m toying with the prospect of DIY water injection. I have seen nozzle locations before and after the turbo. Before turbo can lead to bad compressor wheel erosion so I hear, but MUCH easier to build since the water does not have to be injected under positive pressure. After turbo injection requires high psi pump, tapping throttle valve, etc. One web site states that a misting nozzle can be used to atomize the water/alcohol before it gets to the blades with NO erosion. Any thoughts on this. I'd hate to kill a new 16G with ignorance. Any thoughts on water injection in general would be welcome in general, good or bad. And no, I cannot afford an Auquami$t. Any other DIY's out there? Thanks! Jrod
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92 Tsi AWD, ported/clipped small 16G, 2.5 cat back w/test pipe, Phantom 2.5" downpipe, Supra IC, DIY upper IC pipe, 2G TB elbow, K&N, Magnecores, Walbro 255, 2G MAS, Mazda RX-7 550's, Spoolinup AFPR, 5-spd, 4 bolt diff.'s
dont put it before the turbo. you cant compress water, so itll probably just drop out of the air and puddle in the bottom of the compressor and intercooler.
put it in the UICP or TB elbow.
you have to use the correct spray nozzle so that it makes a fine mist instead of squirting a stream. thats why you need high pressure too.
if it just squirts in under low pressure, its not going to evaporate and absorb heat.
and when you DO get it all working, you should just run straight alcohol. its called Denatured alcohol i think. id prefer alcohol injection over water injection or water/alcohol injection. the proof is in the Alky V8 4x4 and race cars. the alcohol cools down the intake SO much that a friend of mine had FROST on his manifold. try that w/ water/alcohol mix.
chris
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Back in the Saddle again! visiting from Supra country, dabbling in DSM's with RX7s on the side.
Can you give me some numbers on the denaturated alcohol, as in its heat absorption rate. I know that water is better at it than isopropyl alcohol, but how much better is denaturated. Another thing that you have to worry about is seals and pumps when running Alky. Here is a list of sites that i have found.
Originally posted by flubyux2 itll probably just drop out of the air and puddle in the bottom of the compressor and intercooler.
chris
This is not true, I have tried it on a my GSX with 12.7 @112.1 time slips all day; for two years(20psi on 91 octane to work each day). Also I have put, before the turbo, water injection on a TO4 turbocharged 351; this ha worked 454-shmashing-wonderful for more than 3 years. I yank 2.5 ton boats around like hondahs with no sings of "erosion."
-Dan
Thanks for the info. This originally started when i tried to buy a MKIV IC for it. GOOD LUCK IF YOU WANT ONE!!! I gave up and started pursuing this instead. I think the trick to BEFORE turbo application is VERY GOOD atomization, but even here, nozzle placement is bound to play a part. Some guys place the nozzle somewhere towards the middle of the air intake, others inject close to the intake wall. All that hardware protruding is bound to interrupt smooth air flow. In my case, I built a 3" ABS intake to comlement my K&N. I think placing it near the wall just prior to the elbow bend, protruding the misting nozzle just slightly into the air path, will do the trick. I'll keep a VERY close eye on that blade though. I think erosion problems that i hve read about are caused by "squirters" that rely on the blade to "chop" the water and atomize it. I aint no rocket scientist, but this should appear as an inherently bad idea to anyone. Squirt a garden hose into a fan sometime. Now take a Windex spray bottle and squirt that into the same fan. I'm gonna try to utilize my stock fuel pump that is just sitting in the basement. This amount of pressure should provide enough force to inject either prior to or past the turbo. Any further thoughts, please chime in. Thanks!
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92 Tsi AWD, ported/clipped small 16G, 2.5 cat back w/test pipe, Phantom 2.5" downpipe, Supra IC, DIY upper IC pipe, 2G TB elbow, K&N, Magnecores, Walbro 255, 2G MAS, Mazda RX-7 550's, Spoolinup AFPR, 5-spd, 4 bolt diff.'s
lol...its not wise to squirt anything into your compressor blades.
a drop of water hitting your compressor wheel when its spinning at 150000 rpm will make it explode.
at least put it AFTER the compressor elbow.
and the idea about water being incompressable is real. you cant compress liquid, if you could then our hydraulic clutches and brakes as we know them, would Not work.
and my theory about water dropping out of the suspension and puddling is just as valid as fuel dropping out of the mixture on a draw-through carburetion turbo system. the fuel de-atomizes and collects on the bottom of the compressor housing, piping and intercooler. and one back fire, and you will have yourself a nice hood BBQ. and gasoline evaporates more readily than water does, which would make it LESS likely to drop out of the mixture. and since water is evaporates LESS readily, that means it would be MORE likely to drop out of the suspension.
and, as far as finding latent heatvalues and what not, just do a search, there are several other threads about water injection.
chris
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Back in the Saddle again! visiting from Supra country, dabbling in DSM's with RX7s on the side.
I've seen discussion on this topic in yahoo groups. Basically the thoughts are that if you mount the nozzle after the turbo you reduce the efficiency of the IC because of the reduced heat differential and it seems best to mount before the TB to reduce air and cylinder temps. A least on guy is running on nozzle after the turbo and another before the TB with success. I run one nozzle before the TB on 91 octane, alamo smic, and have run 19 to 20psi but I am still tuning.
The aquamist nozzles seem to the one of choice (around $14 a piece).
As for the water vs. alcohol, a 50/50 mix of methonal and water is the best and safest mixture. 100% alcohol is explosive and very dangerous undiluted. Water also absorbs heat better that any alcohol (methonal is very close and adds some additional fuel with a higher octane rating).
I'm getting methonal for just over $1 a galloon from a local shop. Denatured alcohol is being used by some but isn't as good as methonal "the best alcohol to run". For that matter a lot of people, including me at times, are running blue windshield washer fluid.
I saw one guy that had two nozzles also, one before IC and one after. He made runs with only one nozle or the other turned on, then runs with both turned on. I was surprised to see that placing one before the IC AND one after gained the guy 4-5 degrees MORE total timing than just one nozzle alone. In fact, the run he made with only the TB nozzle only gained him 1-2 degrees advance; hardly worth it. Its in one of the links above. So I am gonna try the two nozzle thing, using one solenoid and a tee after it to split the flow, and reduce the nozzle sizes by half. I see a lot of guys get fittings from McMAster.com. Way cool site. Others use NOS nozzles, but they erode since they are aluminum. I'm gonna use the Aquamist nozzles, since I am saving big by using a used Acura EFI fuel pump rather than buy a new one. Alcohol might kill it, we will see. I have heard Bosch VW pumps are stainless inside, gonna check that too. I'm starting my parts collection tonight, should have it on by Sunday if I can get nozzles that fast. Jrod
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92 Tsi AWD, ported/clipped small 16G, 2.5 cat back w/test pipe, Phantom 2.5" downpipe, Supra IC, DIY upper IC pipe, 2G TB elbow, K&N, Magnecores, Walbro 255, 2G MAS, Mazda RX-7 550's, Spoolinup AFPR, 5-spd, 4 bolt diff.'s
The guy who's is running two nozzles is at www.darklightning.com I believe. I think his first run was with the nozzle after the IC and the second nozzle before the TB which seems to make sense based on his timing numbers. A nozzle right before the TB is the best location and should be your first choice. It's easy and works great.
Running multiple nozzles may reduce the pump pressure enough that the water isn't atomized enough so do some search--care should be taken if going this route.
As far as atomization goes, 100 psi or 150 psi pumps will provide more than enough pressure to accomplish this, even for two large nozzles. But regardless of that, if you install a nozzle preturbo I will personally drive out to where ever the hell you live to smack you. I've seen in done, and after mild use the compressor blades look sandblasted.
I'm the owner of DarkLightning.com, by the way, and I do run a dual nozzle system. Full details can be had at my Water Injection VFAQ
Hey Lightning. I've started collecting my parts, got my Shurflo last night in 100psi configuration. I saw one guy that had used a 100psi Shurflo with a return line. Wasnt sure what this was for really, I guess it acted like a fuel return line. Seems like this would make your pump run more. An accumulator sems to be the way to go to provide instant pressure. This leads me to one of my two questions. Does the accumulator need to be bled? I see you have an air bleed on yours, at least I think thats what it is. It seems like a SMALL amount of air would be a good thing to provide some backpressure to keep the pump from switching on/off so much and provide instant pressure as soon as the pressure switch/relay go off after being activated by boost. Or does the accumulator build pressure and hold it with a check valve?
I was also trying to figure out a way to wire the pump so that it gets more voltage as the boost increases, thus injecting more water as it is needed in more of a metered fashion. There are Grand national kits with controls similar to this. To tune, you get on the gas and add water until it starts to bog then back off of the water a little. Autospeed.com suggested using an electric trailor brake as an actuator. Greater the acceleration, the greater the voltage and thus more water. A lot of what I have read indicates metering is the most important thing, and a large shot of water tends to bog the motor until boost can catch up. Have you noticed this to be true?
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92 Tsi AWD, ported/clipped small 16G, 2.5 cat back w/test pipe, Phantom 2.5" downpipe, Supra IC, DIY upper IC pipe, 2G TB elbow, K&N, Magnecores, Walbro 255, 2G MAS, Mazda RX-7 550's, Spoolinup AFPR, 5-spd, 4 bolt diff.'s
Originally posted by jrotten I saw one guy that had used a 100psi Shurflo with a return line. Wasnt sure what this was for really, I guess it acted like a fuel return line. Seems like this would make your pump run more. An accumulator sems to be the way to go to provide instant pressure.
I agree. The return line idea is interesting but I don't want my ShurFlo pump running constantly. It's not a loud pump, but it's not exactly quiet either, plus constant use leads to shorter pump life.
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This leads me to one of my two questions. Does the accumulator need to be bled? I see you have an air bleed on yours, at least I think thats what it is. It seems like a SMALL amount of air would be a good thing to provide some backpressure to keep the pump from switching on/off so much and provide instant pressure as soon as the pressure switch/relay go off after being activated by boost. Or does the accumulator build pressure and hold it with a check valve?
The pressurized line from the pump runs to a brass 'T'. One side of the T is the accumulator, which is always pressurized so long as the pump is doing it's job. The other is the solenoid, which leads to the nozzles. The accumulator maintains pressure in the system between the pump and the solenoid, that's it's only function in life. And no I've never bled it, just hooked it up and ran with it.
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I was also trying to figure out a way to wire the pump so that it gets more voltage as the boost increases, thus injecting more water as it is needed in more of a metered fashion. There are Grand national kits with controls similar to this. To tune, you get on the gas and add water until it starts to bog then back off of the water a little. Autospeed.com suggested using an electric trailor brake as an actuator. Greater the acceleration, the greater the voltage and thus more water. A lot of what I have read indicates metering is the most important thing, and a large shot of water tends to bog the motor until boost can catch up. Have you noticed this to be true?
Think about it another way: don't vary the pump speed, vary the solenoid duty cycle. This is how a fuel injector works. Amount of water sprayed is related to how often the fuel injector's solenoid is open. Aquamist sells a kit to do exactly this, I think it's the 3S but I could easily be wrong; all I know for sure is that there are $$$ involved.
I look at it like this: when do I need water? I need water at WOT when and only when I hit boost pressures higher than my fuel and intake system can handle. That's it. I need to revise my website to reflect this, but I have water injection kick on at 18psi now. And think about it, I have a fixed amount of water available instantly upon command, and that fixed amount of water was choosen through calculations based on WOT, 90% to 95% injector duty cycle, and 22-23 psi.
I drag race and street race which are typically very close in concept, massive straight line acceleration. If I were involved in more of an autocross type event, I'd be more concerned with water injection at partial throttle and partial boost, but I'm not.
This setup WILL NOT WORK FOR EVERYONE, but it has a niche. I happen to be in it.
</soapbox>
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DarkLightning.com : '97 AWD, missing a flywheel bolt
To run 50%-50% water and methanol use Windsheild Washer fluid. Most is made up to that spec. SOME uses glycol so look at the labels. Many 3sir's use this as do I in my ERL system 1s. Works great and you can find it anywhere for $1 a gallon.
I use the largest .7 jet and even at 22psi she don't go thru that much water-alky.
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water injection nozle location?
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