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Thread: Staggered H2O/Meth injection

  1. #21
    Super Moderator Turbo Mopar Staff contraption22's Avatar
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    Re: Staggered H2O/Meth injection

    Quote Originally Posted by johnl View Post
    Another idea, obviously not new - why not pressurize a sealed container of meth/water with boost? and then let boost drive a nozzle, fed from that container, ahead of the compressor? No need for a pump or a Hobbes switch or electrics. Completely progressive too.

    To prevent vacuum from sucking the mix back into the intake during deceleration/off boost, place the boost barb connection well above the "water level," or put a one-way check valve in the boost line to the container.

    If I was in the business of selling H2O/alky injection pumps and solenoids and switches at three to five fold markups, I wouldn't highlight this idea, and, (not to knock Mike) I'd exaggerate the inducer erosion problem.


    Might be necessary to tune the boost to the container with sized orifices? or small diameter vacuum hose? to prevent too much volume of boost air and thence spray, or maybe use one or two small nozzles so that it has a staged delivery? or a small unrestricted nozzle followed by a second larger nozzle pressure switched by a two port (or flow through) pressure relief valve?
    This is how my old system worked. Boost pressurized the reservoir an it sprayed into throttle body ahead of the compressor. I still used a Hobbs switch and a solenoid to prevent siphoning.

    - - - Updated - - -

    Quote Originally Posted by wallace View Post
    You may not need an intercooler depending on how much you intend to inject.
    Many turbo and supercharged drag cars fueled with alcohol do not use intercoolers.
    Mike Marra
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  2. #22
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    Re: Staggered H2O/Meth injection

    [QUOTE=contraption22;1048489]This is how my old system worked. Boost pressurized the reservoir an it sprayed into throttle body ahead of the compressor. I still used a Hobbs switch and a solenoid to prevent siphoning.

    - - - Updated - - -

    Did you ever log the reduction when spraying the fluid? Did you see any erosion of the compressor wheel?

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    Re: Staggered H2O/Meth injection

    I didn't spray into the compressor because I used 100% methanol and that made me paranoid.

    I have to redo my methanol system at some point and I was thinking about adding a boost barb to the lid of my tank simply because I had drilled a large hole in the top to allow the tank to not create vacuum when fluid moved out through the pump (was having priming issues that should be helped by running it upside down). I don't like having that hole open doing nothing. I had 34gph made up of 3 nozzles but I only have 3 ports for nozzles. Maybe I could run two 14's pre TB and run a 6gph nozzle pre compressor for better atomization and the same overall flow. I never had siphoning issues, just priming issues.

    I had been reading some weird website based in the UK that talked forever about water injection and they got me back to thinking about preturbo injection.
    Brent
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    Re: Staggered H2O/Meth injection

    Quote Originally Posted by wallace View Post
    - - - Updated - - -

    Did you ever log the reduction when spraying the fluid? Did you see any erosion of the compressor wheel?

    Nah man. We're going back..... omg... 20 years ago. I was just a kid playing with dirt cheap mods at the time. I'm not even sure I had a scanner back then.
    Car went faster tho. Got into the 13's which was kind of a big deal for a T1 log car back in the day.

    - - - Updated - - -

    Quote Originally Posted by wallace View Post
    - - - Updated - - -

    Did you ever log the reduction when spraying the fluid? Did you see any erosion of the compressor wheel?

    Nah man. We're going back..... omg... 20 years ago. I was just a kid playing with dirt cheap mods at the time. I'm not even sure I had a scanner back then.
    Car went faster tho. Got into the 13's which was kind of a big deal for a T1 log car back in the day.
    Mike Marra
    1986 Plymouth Horizon GLMF "The Contraption" < entertaining sponsorship offers
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    Re: Staggered H2O/Meth injection

    After reading about it, IMO, the only reason to inject pre-compressor is to trick the compressor into performing like a bigger compressor, to enable a small compressor, with it's low RPM CFM superiority, to extend itself farther into the higher CFM/RPM range where it is inferior. Ideal for a street car.

    As I understand it, lower temperatures, at the tips of the inducer and through the compressor's snail, are enabled with a spray pre-compressor. Further, due to its lower flash point a higher percentage of methanol is preferred. And, the same reason, low flash point, makes it less likely that it will condense/puddle in the intercooler - it stays gaseous.

    As for routing boost to the supply tank, I agree. Doing so will help priming but, more importantly, if it is taken from the lowest point of the intercooler, then it will drain/pump any condensate back to the supply tank. I wonder, however, how much of that boost pressure/signal will be seen at the nozzles though - we are dealing with diaphragm pumps - does their check valve attenuate/cut off that low side pressure signal from being transferred to the high side of the pump? and thereby killing any progression of nozzle PSI with boost?

    - - - Updated - - -

    After reading about it, IMO, the only reason to inject pre-compressor is to trick the compressor into performing like a bigger compressor, to enable a small compressor, with it's low RPM superiority, to extend itself farther into the higher RPM range where it is inferior. Ideal for a street car.

    As I understand it, lower temperatures, at the tips of the inducer and through the compressor's snail, are enabled with a spray pre-compressor. Further, due to its lower flash point a higher percentage of methanol is preferred. And, the same reason, high flash point, makes it less likely that it will condense/puddle in the intercooler.

    As for routing boost to the supply tank, I agree. Doing so will help priming but, more importantly, if it is taken from the lowest point of the intercooler, then it will drain/pump any condensate back to the supply tank. I wonder how much of that boost pressure/signal will be seen at the nozzles though - we are dealing with diaphragm pumps - does their check valve attenuate/cut off that pressure signal from the high side of the pump? and thereby killing any progression of nozzle PSI with boost?
    John Laing "The sole condition which is required in order to succeed in centralizing the supreme power in a democratic community, is to love equality, or to get men to believe you love it. Thus the science of despotism, which was once so complex is simplified, and reduced . . . . to a single principle." -- Alexis de Tocqueville "One of the methods used by statists to destroy capitalism consists in establishing controls that tie a given industry hand and foot, making it unable to solve its problems, then declaring that freedom has failed and stronger controls are necessary." --Ayn Rand "To evolve, you don't need a Constitution. All you need is a legislature and a ballot box . . . . things will evolve as much as you want. All of these changes can come about democratically; you don't need a Constitution to do that and it's not the function of a Constitution to do that." -- Justice Antonin Scalia

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    Re: Staggered H2O/Meth injection

    How do I get rid of this double posting stuff? Must be something wrong with my computer. Just started for me but others on here have had the same bug for some time.

    - - - Updated - - -

    How do I get rid of this double posting stuff? Must be something wrong with my computer. Just started for me but others on here have had the same bug for some time.
    John Laing "The sole condition which is required in order to succeed in centralizing the supreme power in a democratic community, is to love equality, or to get men to believe you love it. Thus the science of despotism, which was once so complex is simplified, and reduced . . . . to a single principle." -- Alexis de Tocqueville "One of the methods used by statists to destroy capitalism consists in establishing controls that tie a given industry hand and foot, making it unable to solve its problems, then declaring that freedom has failed and stronger controls are necessary." --Ayn Rand "To evolve, you don't need a Constitution. All you need is a legislature and a ballot box . . . . things will evolve as much as you want. All of these changes can come about democratically; you don't need a Constitution to do that and it's not the function of a Constitution to do that." -- Justice Antonin Scalia

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    Supporting Member Turbo Mopar Contributor Ondonti's Avatar
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    Re: Staggered H2O/Meth injection

    Server/software is having a problem so everything is freezing or double posting.


    I just thought of an exciting terrible idea. Flaming BOV.

    - - - Updated - - -

    Server/software is having a problem so everything is freezing or double posting.


    I just thought of an exciting terrible idea. Flaming BOV.
    Brent
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    Re: Staggered H2O/Meth injection

    Yeah I'd never use methanol upstream of a BOV or intercooler.
    Mike Marra
    1986 Plymouth Horizon GLMF "The Contraption" < entertaining sponsorship offers
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    Re: Staggered H2O/Meth injection

    I hadn't considered the bov...

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    Re: Staggered H2O/Meth injection

    Right, that's where one idea conflicts with another - greater than 50% methanol has a potential to ignite. Below that it won't yet chemical cooling is optimized with greater than 50%. Even at % well above 50% it's hard to light. But, with pressure and a BOV exploding a cloud of it into a hot engine bay . . . .

    So, no one ever should run >50%

    Besides, my assumption is closed loop - BOV routed back into the intake, NOT into the engine bay with its assorted ignition sources.
    John Laing "The sole condition which is required in order to succeed in centralizing the supreme power in a democratic community, is to love equality, or to get men to believe you love it. Thus the science of despotism, which was once so complex is simplified, and reduced . . . . to a single principle." -- Alexis de Tocqueville "One of the methods used by statists to destroy capitalism consists in establishing controls that tie a given industry hand and foot, making it unable to solve its problems, then declaring that freedom has failed and stronger controls are necessary." --Ayn Rand "To evolve, you don't need a Constitution. All you need is a legislature and a ballot box . . . . things will evolve as much as you want. All of these changes can come about democratically; you don't need a Constitution to do that and it's not the function of a Constitution to do that." -- Justice Antonin Scalia

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    Re: Staggered H2O/Meth injection

    http://www.yellowbullet.com/forum/sh...d.php?t=486039

    Never read anything before about forced induction v8's running methanol but this was an interesting progression of a thread. A bit off track with the Mr freeze boost fed bottle setup (not much flow) but wear on the impeller does not seem to be anyone's issue.

    Now I am thinking I might run three 14gph nozzles and put one preturbo. Then run my BOV with a hose that vents things in the right direction (maybe). I would think a dyno would be the most dangerous place (less airflow through the engine bay) and I did not find any flameup issues.

    100% methanol of course. I wonder if methanol was able to backflow through the intercooler and through my BOV when I was running 34 GPH pre throttle body previously. 10:1 compression and probably running pump gas will like this I hope. I don't know how much power I can make simply by dialing back timing. Being stuck at very low boost would make me very slow. I had thought about running E85 again but Seattle is a real hassle to get creative with fuel unless you want to ship coal to China. I miss it being next door. Methanol on top of E85 is awesome.
    Last edited by Ondonti; 07-26-2014 at 05:02 AM.
    Brent
    GREAT DEPRESSION RACING
    1992 Duster 3.0 The Junkyard- Now - Megasquirt II/Extra. OEM 10:1 3.0 + funny business
    - Old - 11.5@125 22psi $90 Stock 3.0 Junk Motor - 516whp 519wtq 20psi 91 oct built 3.0 stock n/a computer
    1994 Spirit 3.0 - 12.3@113 15 psi - Daily Holset He341 280whp 304ft/lb @10psi
    1994 Spirit 3.0 a670 - Wife's - Disassembled
    1990 Spirit 3.0 E.S. 41TE
    1993 Spirit 3.0 E.S. 41TE
    1994 Duster 3.0 A543
    1990 Lebaron Coupe 2.2 TII non IC, T1 31TH
    1981 Starlet KP61 Potential driver, 1981 Starlet KP61 Parts, 1983 Starlet KP61 Drag
    1998 Dodge 12v Cummins 47re 4x4 4dr longbed. No fuel plate. Mack plug, AFC & Spring mods. Boost elbow.

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    Re: Staggered H2O/Meth injection

    Thanks Brent, that YellowBullet thread linked to an excellent thread at UK Aquamist

    http://www.aquamist.co.uk/vbulletin/...read.php?t=251


    And yes, I'm thinking three nozzles, three stages, one pre-compressor, two pre-TB, controlled by three Hobbes switches, and three solenoids. One guy with a dual nozzle system had the pre-TB nozzle (under vacuum) pull the fluid out of the pre-compressor nozzle and supply line (backwards) - thereby sucking the pre-compressor nozzle dry. He fixed it with a check valve; in a staged system a NC solenoid valve ought to do the same thing though.

    I also like the idea of an accumulator between the pump and the solenoid valves to ensure consistent pressure delivery and reduce demands on the pump.

    Relating to boost driven pre-compressor nozzles, as one poster in that thread explained - if you have a pre-TB injector anyway, then use the same pump for both sides, pre and post compressor. Also, relating to inducer erosion, the mist of high psi, as opposed to the small drops of low psi, is preferred.
    Last edited by johnl; 07-28-2014 at 04:05 AM.
    John Laing "The sole condition which is required in order to succeed in centralizing the supreme power in a democratic community, is to love equality, or to get men to believe you love it. Thus the science of despotism, which was once so complex is simplified, and reduced . . . . to a single principle." -- Alexis de Tocqueville "One of the methods used by statists to destroy capitalism consists in establishing controls that tie a given industry hand and foot, making it unable to solve its problems, then declaring that freedom has failed and stronger controls are necessary." --Ayn Rand "To evolve, you don't need a Constitution. All you need is a legislature and a ballot box . . . . things will evolve as much as you want. All of these changes can come about democratically; you don't need a Constitution to do that and it's not the function of a Constitution to do that." -- Justice Antonin Scalia

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    Re: Staggered H2O/Meth injection

    Another comparison they gave for compressor wheel erosion was of draw through carburated turbo setups. Those put a lot of fuel through the turbo and don't seem to have problems.
    Brent
    GREAT DEPRESSION RACING
    1992 Duster 3.0 The Junkyard- Now - Megasquirt II/Extra. OEM 10:1 3.0 + funny business
    - Old - 11.5@125 22psi $90 Stock 3.0 Junk Motor - 516whp 519wtq 20psi 91 oct built 3.0 stock n/a computer
    1994 Spirit 3.0 - 12.3@113 15 psi - Daily Holset He341 280whp 304ft/lb @10psi
    1994 Spirit 3.0 a670 - Wife's - Disassembled
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    1993 Spirit 3.0 E.S. 41TE
    1994 Duster 3.0 A543
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  14. #34
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    Re: Staggered H2O/Meth injection

    When staging, which nozzle should turn on 1st - Pre-compressor or pre throttle body?


    Since the point of pre-compressor H2O/methanol spray is to enhance the efficiency of the compressor and since spraying too early may slow the wheel and therby impede spool up, I'm wondering if, on say a 20 pound system, maybe start spray pre-TB at for example 10 pounds, then spray pre-compressor at maybe 15 to cool and stretch the compressor map into the higher boost zones.
    John Laing "The sole condition which is required in order to succeed in centralizing the supreme power in a democratic community, is to love equality, or to get men to believe you love it. Thus the science of despotism, which was once so complex is simplified, and reduced . . . . to a single principle." -- Alexis de Tocqueville "One of the methods used by statists to destroy capitalism consists in establishing controls that tie a given industry hand and foot, making it unable to solve its problems, then declaring that freedom has failed and stronger controls are necessary." --Ayn Rand "To evolve, you don't need a Constitution. All you need is a legislature and a ballot box . . . . things will evolve as much as you want. All of these changes can come about democratically; you don't need a Constitution to do that and it's not the function of a Constitution to do that." -- Justice Antonin Scalia

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    Re: Staggered H2O/Meth injection

    People were actually talking about it improving spool because of improved efficiency. Nothing really proven.
    Brent
    GREAT DEPRESSION RACING
    1992 Duster 3.0 The Junkyard- Now - Megasquirt II/Extra. OEM 10:1 3.0 + funny business
    - Old - 11.5@125 22psi $90 Stock 3.0 Junk Motor - 516whp 519wtq 20psi 91 oct built 3.0 stock n/a computer
    1994 Spirit 3.0 - 12.3@113 15 psi - Daily Holset He341 280whp 304ft/lb @10psi
    1994 Spirit 3.0 a670 - Wife's - Disassembled
    1990 Spirit 3.0 E.S. 41TE
    1993 Spirit 3.0 E.S. 41TE
    1994 Duster 3.0 A543
    1990 Lebaron Coupe 2.2 TII non IC, T1 31TH
    1981 Starlet KP61 Potential driver, 1981 Starlet KP61 Parts, 1983 Starlet KP61 Drag
    1998 Dodge 12v Cummins 47re 4x4 4dr longbed. No fuel plate. Mack plug, AFC & Spring mods. Boost elbow.

  16. #36
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    Re: Staggered H2O/Meth injection

    I'm pretty darn sure that I got my charge air to be below ambient in the intake. I wasn't even running that much GPH. I was in Florida at the time and the ambient temps were in the 90's and humidity was probably the same! LOL I'd make a pull and the intake would be cold to the touch and have condensation on it!

    As long as the flow of alky before the compressor is very fine, then it will flash off into a gaseous state and reduce the temperature of the air as well as increase the density, basically making the turbo think it is at a lower altitude with cooler air. I'm not confident enough to say that this is the reason for the increased compressor efficiency and not their theory on making a better seal between the compressor and the housing, however this makes much more sense than the sealing thing. Methanol turns to vapor around 180-230F depending on ambient pressure (1-3 bar is what I am quoting here). The outlet temperature of the compressor is most likely going to be higher than this and the pressure is higher, so the vapor temperature is going to be higher. Now, another thing to keep in mind is velocity of the charge air in the pipes. Even though the charge air is going to be below the vapor temperature the methanol should still be atomized and the charge air should carry it along. Now, if you have an intercooler that has some dead spots in the end tanks I could see this maybe being a problem. However the charge is going to be so turbulent I just don't see it happening (YMMV). This is assuming that it is a very low flow that is being injected before the compressor.

    Now, because we know that the vapor temperature is above 180F, I think it would be a good idea to know at what boost level the compressor is spitting out charge air that is higher than that. I would go so far as to make sure it is higher than the next bar(atmosphere) up from the boost you are running (that's my own opinion). Remember that the charge is going to cool off as the methanol evaporates and the pressure is increasing, so the temperature at which it will condense is going to be higher. You could use the compressor map and some math to figure it out, or a thermocouple in the exit side of the compressor will also tell you. Heck, using the thermocouple you could in theory make a controller that is temperature based (remember that it won't be a constant boost pressure where this temperature occurs because the ambient air the turbo is sucking in is going to change). You would certainly need a fast responding thermocouple, but because the temperature is relatively low an open tip thermocouple would probably be alright. The only worry here is if the tip of it were to break off...it could potentially be eaten by the engine.

    Anyway, in my typical "engineer thinking" fashion I am probably overthinking and overcomplicating things, but hey...it's fun to think about...at least to me.

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    Re: Staggered H2O/Meth injection

    Something I read elsewhere mentioned that a lot of extra heat added by the turbo beyond optimal is due to friction of the air against the housing at the tip of the wheel which is where the alky also travels too so those local spots will be hot enough to vaporize and also the friction heat would be toned down right away. Keeping the charge denser at the tips is a good thing.
    Brent
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    1992 Duster 3.0 The Junkyard- Now - Megasquirt II/Extra. OEM 10:1 3.0 + funny business
    - Old - 11.5@125 22psi $90 Stock 3.0 Junk Motor - 516whp 519wtq 20psi 91 oct built 3.0 stock n/a computer
    1994 Spirit 3.0 - 12.3@113 15 psi - Daily Holset He341 280whp 304ft/lb @10psi
    1994 Spirit 3.0 a670 - Wife's - Disassembled
    1990 Spirit 3.0 E.S. 41TE
    1993 Spirit 3.0 E.S. 41TE
    1994 Duster 3.0 A543
    1990 Lebaron Coupe 2.2 TII non IC, T1 31TH
    1981 Starlet KP61 Potential driver, 1981 Starlet KP61 Parts, 1983 Starlet KP61 Drag
    1998 Dodge 12v Cummins 47re 4x4 4dr longbed. No fuel plate. Mack plug, AFC & Spring mods. Boost elbow.

  18. #38
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    Re: Staggered H2O/Meth injection

    The added heat is due to a few things.

    First, we all know that when you compress something, it gets hotter.

    The statement of the additional heat coming from friction of the air against the housing is also accurate. The air is more dense and is now "rubbing" against the housing walls. There's a lot of fluid dynamics that goes on, but that description is easy enough for most everyone to understand.

    The other part to this is the compressor efficiency. Because the aerodynamics of the compressor is fixed, it is the most efficient and "happy" in a certain area. We see this as the "island" on the compressor map. What that is actually saying is that the compressor is using its designed in aerodynamics to the maximum. Now, if we go off to the right of the map, the "island" lines are indicating compressor wheel rpm. When we start trying to make the turbo move more air than it is designed for we have to spin the compressor faster.

    Now, remember that the compressor blades are airfoils, just like wings. Now, I'm not 100% sure that they actually use airfoil cross sections or not due to the fact that centrifugal compressors work differently than axial. However, the same principle applies to what I'm heading toward.

    We all know what the speed of sound is. I don't know how many of you all know about airplanes, but airplanes with propellers have a limit on how fast they can spin their prop. It's not that they couldn't spin it faster, it's that the prop becomes inefficient and can start vibrating because the very tips of the blades are breaking the sound barrier. They already get very close as it is (and do on occasion go supersonic for short bursts). Helicopters make the noise that they do because of the same thing...the tips of the rotors are supersonic. Now, the same happens with jet engine compressors in closed housings. If the tip speed goes supersonic the efficiency goes way down. Take this and translate it to our turbos. The faster we spin the compressor wheel, the closer it gets to having tip speeds at or above supersonic. Once that happens, this is when we tell people the compressor is doing nothing but blowing hot air. The tip speed has gone supersonic, and the air gets heated up even beyond what it would normally be. There's a bit more going on, but I think I got to where I needed to.

    A denser charge will increase the speed of sound, so you could spin the compressor harder, but I wouldn't do it because it's not consistent.

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    Re: Staggered H2O/Meth injection

    Quote Originally Posted by Ondonti View Post
    People were actually talking about it improving spool because of improved efficiency. Nothing really proven.
    But the question is, when or where on the compressor map does that improved efficiency occur? What I read, relating to pre-compressor spray delaying spool up, I took to reference the simple effect of the mass of the fluid hitting the inducer's blades at the very moment when they are just beginning to accelerate, and then . . . . any cooling effect at that critical moment also increases the mass (not to say density) of the gas, that the blades are trying to accelerate.


    As Reaper points out, it is a dynamic question given that the flash point of the methanol changes with pressure. Yes, at the inducer's blade tips, the heat rise likely is so quick and high that it likely overwhelms any delay in flash point caused by pressure rise - but at what inducer speed is the tipping point? Where on the map does that overwhelming begin? And, yes, ideally a thermocouple (as Reaper says - as a measure of but one part of the two part temperature & pressure complex) could control when and how much pre-compressor spray.

    Further complicating it - we should consider that, for safety's sake, the spray ought to be half water with a much higher flash point and a different weight or mass.
    Last edited by johnl; 08-01-2014 at 01:35 PM.
    John Laing "The sole condition which is required in order to succeed in centralizing the supreme power in a democratic community, is to love equality, or to get men to believe you love it. Thus the science of despotism, which was once so complex is simplified, and reduced . . . . to a single principle." -- Alexis de Tocqueville "One of the methods used by statists to destroy capitalism consists in establishing controls that tie a given industry hand and foot, making it unable to solve its problems, then declaring that freedom has failed and stronger controls are necessary." --Ayn Rand "To evolve, you don't need a Constitution. All you need is a legislature and a ballot box . . . . things will evolve as much as you want. All of these changes can come about democratically; you don't need a Constitution to do that and it's not the function of a Constitution to do that." -- Justice Antonin Scalia

  20. #40
    turbo addict
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    Re: Staggered H2O/Meth injection

    If you lower the air inlet temperature with the same inlet pressure the air on the discharge will correspondingly drop in temp. The compressor efficiency is fixed by the physical design. The lowered discharge temperature means a denser charge for the same boost pressure taking away the amount of oxygen displaced by the fluid would give you the increase in oxygen. I pasted a link that has the formula for this as well as some other info.

    http://www.gnttype.org/techarea/turbo/turboflow.html

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