Landracing Forum
Tech Information => Water/Methanol Injection => Topic started by: landracing on May 11, 2007, 03:31:43 AM
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So we know you have a system and different nozzle sizes from Snow Performance. But what is a rule of thumb or a calculation estimate on the amount that is needed.
Just curious to know how it is calculated, and if its calculated on a single nozzle system. What happens when you want to run four individual nozzles on a 4 cyl FI motor?
I'm thinking of a system but using a fuel rail setup for the nozzles. Which leads to placement of nozzles. Before or after the fuel injector or will it not matter?. I know this will open a can of worms, but im pretty unfamiliar on the setup or the possibilities.
Jon
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So we know you have a system and different nozzle sizes from Snow Performance. But what is a rule of thumb or a calculation estimate on the amount that is needed.
Just curious to know how it is calculated, and if its calculated on a single nozzle system. What happens when you want to run four individual nozzles on a 4 cyl FI motor?
I'm thinking of a system but using a fuel rail setup for the nozzles. Which leads to placement of nozzles. Before or after the fuel injector or will it not matter?. I know this will open a can of worms, but I'm pretty unfamiliar on the setup or the possibilities.
Jon
Jon is there a reason you want to run 4 nozzles??? Because my memory is so bad I can't remember if you are running an intercooler now or not?? I looked at a picture I have of your bike, is the aluminum box just an air box that goes to the intake runners or is it also an intercooler??
On the side of it there appears to be a single throttle body. I don't know what Nate is going to say, but if you look on page 130 of Dec. 2006 HOT ROD (I could send you a copy) they used Snow's system on a blown vette and the injection point was after two air/air intercoolers and ahead of the throttle body. They used two injectors there, but I think Nate told me they could have used just one.
I would think the further you get away from the combustion chamber the more the water will mix with the air and cool it, but I could be wrong. Their nozzles so finely atomize the water or water/meth mix that you will get complete mixing injecting down stream and it will be equal to all cylinders.
Nate would help you pick the right nozzle size. It might also be on their site. I remember one of the sites that sells these had a place that helps you size, but I think they all have their proprietary nozzles and they probably would not cross reference.
I'm wondering if they would have a small enough nozzle to run 4 in your application??
I'll bet Nate answers some of these questions. Hooley picked up our stuff at their facility yesterday and he was very impressed with their operation and Nate's knowledge along with Matt Snow's, the owner. We look forward to working with their system this summer.
c ya,
Sum
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The intake charge begins to heat up at inlet point where it is compressed and that is where it can begin to do some good.
If your system allowes it to fall out of suspension and puddle , it is a bad design to start. :wink:
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Like Sum had mentioned our nozzles are proprietary and our nozzle selection process is slightly guarded as it's the product of years of r&d and testing.
I can tell you this: we base our nozzle selection on a number of reference points. Depending on your horsepower output, which is indicative of airflow and fuel consumption, and boost level, which is indicative of heat, we inject a percentage of your primary fuel flow rate.
So long as you have an idea as to how much power and boost your making we can get you accurately sized with the nozzle that will work best for your application. We find the the required flow rate and select an appropriately sized nozzle (two nozzles are included in every kit to cover a wide range of flow requirements). If the required flow rate is more than what our largest nozzle can support we simply add in another nozzle.
There really isn't much of an advantage to running multiple nozzles if one nozzle will support the required flow rate. It just complicates the system. Our nozzles do a great job of atomizing the fluid that there are little to no concerns of distribution. When the fluid is being injected it's in a very very fine mist.
In your instance Jon, if we used four of our smallest nozzles you'd have way too much flow. To reduce flow you'd have to reduce system pressure. With reduced pressures comes reduced atomization. It's better to have one large nozzle at max pressure than four small nozzles at reduced pressure.
The longer the fluid is present in the air intake tract the longer it has to pull heat from the air charge. This is great for reducing IATs but this limits how much fluid gets into the combustion chamber where it acts as a fuel and detonation suppresant. We generically recommend that the nozzle be placed before the throttle body or throttle plate that way it has some time to reduce IATs and still act as a fuel.
Thanks,
Nate
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There are several rules of thumb used for picking a WI spray rate.
Most assume a 50/50 mix of water and methanol, on straight water you can get away with less spray due to its higher cooling power than the methanol. It will also typically requires a slight change in ignition timing going to straight water vs water methanol. Something like an additional 2 degrees of timing seems to be common.
Most folks start off running a spray rate of approximately 15% - 25% of the fuel as a starting point.
In the unlimited Air racing world, Unlimited Hydroplanes and the WWII military aircraft, they used a 50% to fuel injection rate on a 50/50 mix of water and methanol. (ie 1 lb of ADI fluid for each 2 lbs of fuel ---- ADI is the term used by the military for water injection stands for Anti-Detonation Injection)
That should get you in the ball park then you need to dial it in to run the least injection you can and still be safe, to avoid over cooling the combustion process.
At least that's my experience.
Larry
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The intake charge begins to heat up at inlet point where it is compressed and that is where it can begin to do some good.
If your system allowes it to fall out of suspension and puddle , it is a bad design to start. :wink:
One point - if you have a centrifugal-type compressor, you really don't want to inject any fluid before it or into it. You can, and people do, with draw-through carbed turbo setups and low-pressure water injection setups, except it isn't a good idea for a couple reasons. One, is that it will erode the impellor blades - even our tiny droplets hitting something spinning 60,000-150,000rpm is going to deform the leading edges of those blades. We have tractor pullers do this - but they replace their turbos very often regardless, so it is less of an issue. Two, a turbo or centrifugal supercharger compresses air with centrifugal force - air, that weighs very little (in comparison to water/methanol). Think what will happen to the tiny droplets as they go through and get slammed into the outer compressor housing wall - recollect into larger droplets and we get much less benefit than with smaller droplets.
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We are speaking primarily of racing here and draw - through has been very effective even with the fluid volumes seen with NOS over Alky.
I have a 6 cyl. Honda for example that has been setup with a draw-through gas system and about 40k miles with no erosion to the inlet blades.
The gate is set for 25lbs. and the manifold supplies the pressure for the water injection.
We use a selection of commonly available Mikuni pilot jets.
"There is more than one solution as there is more than one problem, but they often share the same objective with simular results." (me) :wink:
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Pre-compressor injection on turbocharges can be made to work but it is not suitable for most people.
It can significantly improve the efficiency of the compressor due to the thermal effects it has on the air under compression.
It takes very little water injection to achieve these gains (only a couple percent of the air flow by mass).
I used it on the street for over a year with only minor erosion of the impeller, and with a different design on the system it does not necessarily erode the impellers.
It generally is only appropriate for users that cannot get a big enough turbocharger to meet their needs. The result of the WI pre-compressor makes the turbo act like it is bigger than it really is.
(oh by the way the military aircraft ADI systems used in WWII on the Pratt and Whitney 2800 and other engines use pre-compressor injection of both fuel and ADI fluid)
Larry
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There is some interesting info here http://www.rbracing-rsr.com/waterinjection.html, including an online calculator .
Hope i'm not stepping on Snows toes.
I was thinking of putting 4 jets after my plenum mounted intercooler and trying to size the droplets to be small enough to be dispersed in the cyl but large enough to not vaporise before combustion, intending that the intercooler do its job and water inj be for detonation suppression without occupying too much combustion chamber space ....comments welcome!
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The WRC folks are having good results as I understand it, going to direct port injection for the WI setup. This allows them to tune by cylinder to be absolutely sure they get uniform mixture. The down side of that setup is if you lose a jet due to it plugging you have a fatal lean out in that one cylinder where a manifold type injection will suffer less if a single jet in a multi-jet setup plugs up.
WRC is one of the few racing catagories that still allows WI and also has a sustained high power environment so it would probably be worth while for folks to investigate how they do things.
Larry
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Multiple nozzle systems can definitely be used however we've seen that because our nozzles atomize fluid so well that distribution typically isn't an issue. You can run individual nozzles per cylinder if you've got the horsepower/heat/airflow to support it. We typically try to make things as simple as possible and provide a system that is more or less "bolt on". Obviously we can do whatever is needed to support different applications and horsepower levels.
In regards to the nozzle placement for cooling versus consumption as a fuel: We have a generic recommendation that the nozzle be placed before the throttle body. This usually provides a "happy medium" that allows for IAT reductions and increased detonation control. The closer you are to the combustion chamber the more the fluid acts as a fuel and the farther away from the combustion chamber the more the fluid acts as an intercooler. Data logging and tuning are normally the best way to determine optimal nozzle placement for your specific application.
In regards to nozzle selection: it is correct in that we base the injection quantity off of a percentage of primary fuel flow. Our nozzle selection guide (and any other guide) is exactly that: a guide. There is nothing absolute in the information we provide regarding nozzle selection because there are so many variable at play on different applications. We can get you close but final tuning is up to the end user.
I hope this helps.
Nate
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: We have a generic recommendation that the nozzle be placed before the throttle body.
Nate
Thanks Nate
Re: quote , does your recommendation vary in relation to throttlebody placement ? single throttlebody car engines would be fairly different to a multiple TB bike in there needs ??
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: We have a generic recommendation that the nozzle be placed before the throttle body.
Nate
Thanks Nate
Re: quote , does your recommendation vary in relation to throttlebody placement ? single throttlebody car engines would be fairly different to a multiple TB bike in there needs ??
Because four of our smallest nozzles would more than likely be too much flow for your bike engine we would recommend using one larger nozzle and mounting it in a common plenum or airbox. If this isn't an option we could look into possible solutions.
Nate
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Good news Jon. We might be stocking a new nozzle that's flows half as much as our smallest nozzle. Maybe your four nozzle setup will work after all.
Nate
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The intake charge begins to heat up at inlet point where it is compressed and that is where it can begin to do some good.
If your system allowes it to fall out of suspension and puddle , it is a bad design to start. :wink:
One point - if you have a centrifugal-type compressor, you really don't want to inject any fluid before it or into it. You can, and people do, with draw-through carbed turbo setups and low-pressure water injection setups, except it isn't a good idea for a couple reasons. One, is that it will erode the impellor blades - even our tiny droplets hitting something spinning 60,000-150,000rpm is going to deform the leading edges of those blades. We have tractor pullers do this - but they replace their turbos very often regardless, so it is less of an issue. Two, a turbo or centrifugal supercharger compresses air with centrifugal force - air, that weighs very little (in comparison to water/methanol). Think what will happen to the tiny droplets as they go through and get slammed into the outer compressor housing wall - recollect into larger droplets and we get much less benefit than with smaller droplets.
Not so sure on turbos, but the WW2 air craft water injected before the centrifugal compressor and made huge gains in power. They also use methanol to keep the water from freezing.
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a draw through turbo set up or injecting anything before the turbo will absolutely wear the turbo impellers and bearings out faster.
kent
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I've run draw-thru turbo systems for over 20 years on boats & cars. Never have I seen any noticeable compressor erosion & certainly never a bearing failure due to this type of layout. Any time I've had to replace a compressor wheel it's been due to FOD not to fuel or water. Maybe others have run less oil pressure and more water or something. Just what I've seen.
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In my experience it depends on the droplet size and location of injection.
Ideally you want a spray as fine as a fog but that is difficult to achieve without high pressure injection.
Pre-compressor injection is used in the industrial world routinely to improve the efficiency of turbine compressors.
It takes very little water to improve the compressor efficiency max of 3% of air mass by weight is the max that gives you any efficiency gain on the compressor itself although your engine may want a bit more.
On my system I did some injection efficiency-compressor and got a small amount of impeller erosion.
On investigation what appears to have been happening is the spray was wetting the inside wall of the intake duct under certain conditions and then beads of liquid water were running down the tube into the spinning impeller as all the erosion was concentrated on the very tips of the impellers, and you could see the liquid path on the surface of the compressor inlet due to oil build up from the PCV system.
The WWII fighter planes injected both the gasoline and the ADI fluid (water injection) directly into the eye of the centrifugal compressor. I know of one person that has done a similar setup with the nozzle located very close to the compressor shaft nut and spraying directly on the end of the shaft. The nut spinning at 100,000 rpm beats the water jet into a micro fine spray moving radially out toward the compressor impellers, and has shown no signs of compressor erosion according to his accounts.
NACA designed a injection impeller that did about the same by drilling very small holes in the impeller hub pointed out toward the impellers and supplied the water to the impeller hub.
In my next setup I will take measures to prevent wall wetting, and have some trip points to re-suspend any water that runs down the intake.
The erosion I mentioned on my compressor impeller had no measurable impact on the compressors performance, and took months of daily driving to occur.
You might find this forum thread interesting reading regarding pre-compressor injection.
http://www.aquamist.co.uk/phpBB2/viewtopic.php?t=267
Larry
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In my experience it depends on the droplet size and location of injection.....................................You might find this forum thread interesting reading regarding pre-compressor injection.
http://www.aquamist.co.uk/phpBB2/viewtopic.php?t=267
Larry
Great thread and you did a good job of explaining what is going on. I think I even understood most of it 8-) . I saved it for future reference. Thanks,
Sum
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Here is our water injection system.
(http://i162.photobucket.com/albums/t246/bvillercr/IMG_1488.jpg)
(http://i162.photobucket.com/albums/t246/bvillercr/IMG_1491.jpg)
Nosle pointing directly into the compressor.
(http://i162.photobucket.com/albums/t246/bvillercr/IMG_1492.jpg)
Injector nosle with an enderly jet.
(http://i162.photobucket.com/albums/t246/bvillercr/IMG_1493.jpg)
our little water tank. Do you recognize the colored markings? If we put methanol in it it would put us in a fuel class. We put sealed bottle water into the tank in front of the inspectors and they seal it.
(http://i162.photobucket.com/albums/t246/bvillercr/IMG_1489.jpg)
This aluminum cover is used because we blew the top off of the plastic twist lid under boost.
(http://i162.photobucket.com/albums/t246/bvillercr/IMG_1490.jpg)
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Manifold pressure supplies and regulates the water volume.
What a concept !
Reduce the size of the filler to a screw in pipe plug and your troubles with that are over. :wink:
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Manifold pressure supplies and regulates the water volume.
What a concept !
Reduce the size of the filler to a screw in pipe plug and your troubles with that are over. :wink:
Jack, I think you would be disappointed to see what kind of atomization you get using manifold pressure to pressure your injection system. There is a Ford-specific water/methanol injection system available that uses this type of operation. With low boost pressures, the fluid simple dribbles into the intake providing zero benefit. Proper atomization is the key to success as it gives the most surface area for cooling and equal distribution.
Nate
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A competitor of ours released a water injection system specifically for diesels. Their system uses Hilborn/Enderle mechanical fuel injection type nozzles. We did some testing to see what kind of atomization these types of nozzles really produce. Please see the following:
Low speed shot of competitors nozzle - notice the non-uniform spray pattern:
(http://www.edition719.com/gallery/d/12807-3/DSC01104.JPG)
High speed shot of competitors nozzle - notice the poor atomization, streaming, and fan spray:
(http://www.edition719.com/gallery/d/12811-3/DSC01108.JPG)
Here is the Snow Performance 375 ml/min nozzle doing what it does best:
(http://www.edition719.com/gallery/d/12804-2/40375w-pattern2.jpg)
Keep in mind that the competitors nozzle was tested at 150 psi of line pressure. Line pressures below 60 psi will not create very favorable atomization. This is the main reason why systems that use manifold pressure to pressurize the reservoir don't work very well.
Nate
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Nate I think you would be disappointed to see how
many records JackD (and others) broke using this method........
Joe
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I have seen fluids sprayed at various delivery rates and with various pressures on injection systems and know how they work.
I should send some of my collection of pre-adomizer nozzles and some with replaceable inserts that replace the flair feature on the supply ends.
They are used for not only for cooling fluid but as the primary supply for fuel.
The system that is being sold does take some advantage of modern electronic controls is certainly good for many applications, however it has not reinvented the wheel that serves many others just fine for many years in the past and for the foreseeable future.
If you think you need it, you probably do. :wink:
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A competitor of ours released a water injection system specifically for diesels. Their system uses Hilborn/Enderle mechanical fuel injection type nozzles. We did some testing to see what kind of atomization these types of nozzles really produce. Please see the following:
Low speed shot of competitors nozzle - notice the non-uniform spray pattern:
(http://www.edition719.com/gallery/d/12807-3/DSC01104.JPG)
High speed shot of competitors nozzle - notice the poor atomization, streaming, and fan spray:
(http://www.edition719.com/gallery/d/12811-3/DSC01108.JPG)
Here is the Snow Performance 375 ml/min nozzle doing what it does best:
(http://www.edition719.com/gallery/d/12804-2/40375w-pattern2.jpg)
Keep in mind that the competitors nozzle was tested at 150 psi of line pressure. Line pressures below 60 psi will not create very favorable atomization. This is the main reason why systems that use manifold pressure to pressurize the reservoir don't work very well.
Nate
Looks good, what car or bike are you running it on. What are your performance gains with and without?
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Maybe the Webmaster can tell us how it works on the turbo 600 :-D
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Nate I think you would be disappointed to see how
many records JackD (and others) broke using this method........
Joe
Just because they had it on there doesn't mean it did anything worth while.
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The people that depend on atomization of very large volumes of liquid fuel with no more than the pressure drop in a carburetor and appropriate manifolding will be very disappointed to hear it won't work.
Who dares tell them ?
Not Me, Ima gonna let you.
As I have said, it is probably a fine system that is useful in many situations but doesn't satisfy the needs for everybody.
It is like the reinvention of the wheel, the best you can hope for is to uniquely modify it for a particular market and then you have sell it. :wink:
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It is like the reinvention of the wheel, the best you can hope for is to uniquely modify it for a particular market and then you have sell it. :wink:
Well we're definitely not trying to reinvent the wheel but we sure can improve it and that's what we've done. The idea and viability of water/methanol injection is nothing new just like the idea and viability of a gasoline powered internal combustion engine is nothing new either. It's pretty obvious that in the last one hundred or so years there have been vast improvements in engine management systems. The whole suck-squeeze-bang-push idea hasn't changed one bit but again, thanks to modern engine management advancements, the whole system has improved. I'm sure even the most rudimentary water/methanol injection systems work but water/methanol is all we do here at Snow Performance and we've dedicated ourselves to provide the best that there is.
Nate
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And for that they are to be congratulated.
"Dedication is a large measure of success, but not at the expense of the equally successful that chose to do it another way that better fits their real needs." (me)
"It is always best to ride the horse in the direction he is going."
(From an Old Indian saying.)
Some Old Indians are a lot smarter than they are given credit for. :wink:
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Here is our new blower and water injection system.
(http://i162.photobucket.com/albums/t246/bvillercr/IMG_1521.jpg)
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hey that looks like a pretty good spray pattern.
Jon
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(http://i162.photobucket.com/albums/t246/bvillercr/IMG_1521.jpg)
$5 says the leaf blower and garden hose works better. :wink:
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At least the blower is clean :evil:
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Leave it to a hot rodder to squirt water into something that is plugged in and call it R & D!
And you realize that you couldn't use this auxiliary (2nd) motor unless you run a streamliner. And then you'd have a problem classifying it... electric - gas - hybrid. Course you could always put the lectric motor into a trailer. I heard SCTA allows that (only a rumor though).
And will the extension cord be considered leaving parts on the track?
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We have been keeping the Lakester a secret from Jim for awhile and don't any of you spill the beans now and that includes anybody that reads this for him. :wink:
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Anything that suppresses shrapnel formation one time is worth the ticket. Doing it for pennies is genius. Extra ponies as a benefit might get you a couple more mph but the wear and tear on the pocketbook is the true benefit; unless you only need 2 mph more.
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You don't want to run it through turbine blades but even snow or chunked ice that is introduced to the intake path in appropriate amounts will not only benefit from the thermal capacity but for sure be atomised by the time it gets to the combustion chamber.
Think inner inner cooler.
If one can make room for all the associated do-dads with a turbo and an intake cooler, what is wrong with the NA pilots.
Are they missing some power ?
A very famous liner had the best NA engines available that tested excellent on the Dyno.
They failed to produce enough power in the car because the conditions inside caused the inlet temperature to go over 300 deg.
It is not just altitude that sucks your power (money) on the salt, but (heat build up) time and space too.
Just like tires, few realize how hot they really get under load. :wink:
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My dad wanted me to post these pictures about water injection. Here is some text about Ricardo and his testing.
(http://i162.photobucket.com/albums/t246/bvillercr/IMG_1766.jpg)
(http://i162.photobucket.com/albums/t246/bvillercr/IMG_1767.jpg)
(http://i162.photobucket.com/albums/t246/bvillercr/IMG_1768.jpg)
(http://i162.photobucket.com/albums/t246/bvillercr/IMG_1769.jpg)
(http://i162.photobucket.com/albums/t246/bvillercr/IMG_1770.jpg)
Nate this should help sell some more units.
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Sir Harry definitely knew his stuff. If it wasn't for him I wouldn't have this job. :wink:
Nate