mono4lamar

iTrader: (32)

My one FD has a 42r flowing 85 lbs/min and this is the initial car I would like to test on. I'm building my new FD that will be using a custom spec BW unit that flows 98 lbs/min. I would like to make progress on the one before I build the other so just picking you brain first. I think I might try the same nozzle you're using and just enlarge it a little more to flow around 600cc.

Dudemaaanownsanrx7

iTrader: (23)

If you're looking for 600cc flow around 20 psi then the size will need to be very close to 1mm, just to give you an idea of the drill size you'll need.

I bought a tiny set of bits and drilled it by hand starting with the size that just fit in the hole and progressively going up, took 3 or 4 bits total if I remember correctly. I didn't use a drill out of fear of the bit breaking in the nozzle.

mono4lamar

iTrader: (32)

Excellent thinking as usual on your end by "hand drilling." using a drill will also also for it to enlarge the hole just a little bit more by deflection. I'll start ordering parts next month and slowly but surely setting everything up. I can't remember if you mentioned but what egt's are you tuning to and are they digressing?

Max_Spd

iTrader: (78)

Can you expain the diagram in more detail...there might be confusion/concern about the setup...

Check diagram attached

Dudemaaanownsanrx7

iTrader: (23)

You're concern of the nozzle creating a constant boost leak was addressed earlier in the thread, while it is a source of boost that is constantly bled off, the air-port is very small so the amount of boost that's bled off is tiny compared to the volume of air entering the engine. Just like a pinhole in a garden hose won't change how quickly you could fill a bucket by any significant amount.

The pressure switch can be mounted anywhere that there is pressure. Mine is actually tapped into the tank.(so basically the same as the diagram) I tapped it into the tank so I can easily test the system with an air compressor. It's set at 8 psi so anytime the pressure in the piping/tank/turbo drops below 8 psi the switch cuts off and water stops flowing. I suppose if I didn't have a BOV pressure could stay more constant between on/off throttle and the water could theoretically keep flowing for a period of time.

I also still plan on hooking my boost gauge up to the tank, so I can see what kind of pressure difference there is and get an idea of the exact characteristics going on with the system. I use my profec B as a boost gauge more then my actual gauge, and actually with the water on there I haven't been too concerned with even watching the boost. It definitely adds peace of mind.

Max_Spd

iTrader: (78)

Thanks for the clarification!!!

just startn

iTrader: (33)

Well im goign to be getting around to putting my setup in. Im debateing this tank in the trunk thing. Just about an hour ago i started thinking about it. im trying to think of a second way to pressurize the tank keep everything the way it is but add another pressurizing solution. Im thinking this because pressure drop may be a issue idk. i was also thinking of starting off with a bigger size hose at the turbo and going a few steps down by the time it gets to the tank. My other thought was making something out of a electric tire pump like the ones you plug into your cig lighter. these are just quick thoughts

Dudemaaanownsanrx7

iTrader: (23)

I don't think the pressure will change too too much, the respose will be a little slower. I guess it all depends how vital your system is. If you have a spare boost gauge you should add a T or fitting to the tank and check the boost response at the tank. This will tell you the response and total pressure of the system. Another thing you can try, which i recommend anyway is get an air compressor with a regulator set at 20 psi and test your system, see the total volume of water that it flows in 1 minute.

The tire pump takes you away from the whole point of the system being simple, and it also won't follow the boost curve with varying amounts of water. At that point you might at well just use a regular water pump. A water pump is probably more reliable and easier to setup then a bicycle pump.

Sandro

iTrader: (1)

Brent, did you log/compare data with and w/o AI?

in particular AFR and intake T under the same load (PIM)/rpm and tuning conditions?

Thanks,

- Sandro

Dudemaaanownsanrx7

iTrader: (23)

Yeah AFR doesn't change at all with the water. I think if someone has a change in afr it's probably due to spark output being too weak causing misfires or decreased combustion efficiency.

As far as intake temperature, It doesn't drop like some have claimed, and it doesn't drop like methanol will, but It also doesn't go up under long pulls or higher boost. My air temp is the same for 15 psi as it is at 23 psi, obviously the air should be hotter at higher pressures, but I think the water keeps it in check. I havn't tested without water at 23 psi to see what happens to air temps, and I certainly will not be trying that one out lol. I think the water really just helps in keeping everything happy. On a hot summer day my air temps go no higher then around 45 C on a hard pull, where as before they would start climbing as the intercooler heat soaked. With a nice cool day it stays around 30c. I don't have any logs saved, but thats just what I've noticed.

Sandro

iTrader: (1)

Thanks. Just thinking about it to possibly make more airflow out of my stock twins... I thought a higher AFR could be indicative of more air pumped into the engine...

- Sandro

Dudemaaanownsanrx7

iTrader: (23)

Yes it supposedly will extend the efficiency range of the turbos, but this would only in areas where the turbo is normally maxed anyways. My guess is that typically(with no water) the turbos start putting out more heat then boost, add water to these extremely high temperatures and the water boils and takes a lot of the heat out. When the heat is pulled the car is able to make more power at the higher boost levels, and it's like the compressor map has shifter over to give it more range.

I'm not sure if this is actually what's going on, but I've never seen any technical information on it so it's anyones guess.

Sandro

iTrader: (1)

Yes, I started reading this veeery long and deep thread http://www.aquamist.co.uk/phpBB2/vie...er=asc&start=0 and I believe I understand the basic physic behind it.

But I am questioning the effect of displacing oxygen available for combustion. When water becomes steam, its specific volume changes by a factor of 1,000 which causes "dilution" of the oxygen content. So, while air through the compressor gets denser as a result of the cooldown and - everything else equal - more mass of air gets spit out, its oxygen specific becomes lower - less combustion energy. I am curious to see some test data to see how these two opposing mechanisms work together.

- Sandro

Dudemaaanownsanrx7

iTrader: (23)

I'll have to read that thread when i get home. I'm definitely no expert on it and it's difficult to test something like that, especially since my engine wouldn't survive the boost levels at the point when my compressor becomes maxed without the water injection. One thing to add to your above statement is that water contains oxygen in it. H20. So it wouldn't completely be diluting it. What i find facinating about water is it's made of hydrogen, which has a considerable amount of energy and is even used as a fuel source, and it's also bound with oxygen which burns easily along with fuel sources. but bound together they form the exact opposite. The whole thing is just a mess of different reactions that all works out.

Sandro

iTrader: (1)

Not really... did you ever have any success in burning water or steam?

http://blogs.howstuffworks.com/2009/...nt-water-burn/

Dudemaaanownsanrx7

iTrader: (23)

I burn water everytime i drive my car. *shrug* That's an interesting article, though it doesn't change the fact that water contains oxygen. That's what fish use to breath in water. It explains why water can't be used as fuel though. Now what actually happens to that oxygen in water when its mixed with other oxygen and gasoline as in a combustion engine i don't have any idea. It apparently all evens out though, afr's stay the same, power stays the same or even goes up with the right ignition. It cools things down in the engine which you would think would cause a loss in power, since the energy is contained within that heat. It's mind bottling all the different reactions going on in a water injected turbo engine, even some working against eachother, but in the end making a more reliable and more powerful powerplant.

Sandro

iTrader: (1)

Thank you Brent.

I have always valued your experience, out-of-the-box thinking and solutions.

The car is practically retired for the winter now. But this is something I will look into further and could test next year on my stock twins. Based on your results, it's certainly worth for me trying.

Any idea on what to include in an appropriate "test rig" is welcome.

I already have a 150 Shu-flow pump and other misc. components (nozzles, solenoids, even a controller, etc.) to put into use.

One more thing: any thought on getting rid of the I/C. I mean - assuming the compression could indeed be made close to iso-thermal, i.e. Temp out of the compressor close to outside air Temperature, who would then need an I/C?

- Sandro

Barry Bordes

Sandro, don't worry about "the effect of displacing oxygen available for combustion", just have enough fuel for all of the oxygen available. The rotor doesn't care if its deriving pressure from heat of combustion or steam. Both pressures will drive it and power will be made.

I'm not sure that steam is being produced but at higher temps and boost I suspect that it is.

Also Dude, we can't break the water molecule down that easily.

My best guess on the way water works is that when we start to have a temp runaway that would normally lead to detonation that the water absorbs the excess heat as steam and instead of a catastrophe we make more power.

Barry

Sandro

iTrader: (1)

Thanks Barry, yes I understand what you are saying. That both combustion and water/steam expansion contribute to increasing pressure inside the rotary. As an analogy, gas turbines inject water in the combustion chamber for power augmentation. That way, the turbine acts partly as a steam turbine as well.

But that is true[r] if water enters the combustion chamber more as water than steam. For that purpose, ideally, you would like injecting water right into the engine combustion chamber. But even injecting it before throttle, water does not have much time or conditions (temperature) to evaporate early (in fact water injection only, does not cause much of air intake temperature drop)

But by injecting water pre-compressor, with the [different] objective of moving the compression from adiabatic to isothermal, that water has become steam at the exit of the compressor already, and in the process some oxygen [may not be that much compared to the benefit of higher density, that is what looks like form Berry's results] "available for combustion" [excl. H2O and CO2 ] gets necessarly "displaced"

- Sandro

Dudemaaanownsanrx7

iTrader: (23)

The main problem with injecting water directly into the combustion chamber or even post turbo for that matter, is the atomization is poor and it's harder to ignite the mixture. Also preturbo would only turn to steam once the compressor outlet temps reach somewhere between 225-250 degrees F, since water boils at a higher temp under pressure. Once it goes into the intercooler it may recondence. In any case water is still reaching the combustion chamber because knock is eliminated. I doubt steam being injected would do much good, since it's already pulled whatever heat it can. Like i said, i don't know precisely what it's doing but it works. Thanks for the compliments sandro, i do try to have an open mind and learn where i can. I like having complex discusions like this.

Sandro

iTrader: (1)

I see it... Definitely there is a lot for me to read and learn to get up to speed...

I am half through that aquamist thread on pre-compressor injection, really amazing stuff...

But I guess [I may be wrong] the main purpose of it is to actually reduce temperature at the exit of the compressor (call it shift the map, move from adiabatic to isothermal, or whatever...). This being accomplished just by making water become steam, latent heat of evaporation "absorbs" heat along the compression, so that temperature does not rise (ideally) or does not rise that much (practically). Therefore, water "must" become steam to accomplish that. Note, water does not need boiling temperature to evaporate... http://www.pkwy.k12.mo.us/west/teach...boil/boil.html

So, the way I see [so far] is that we have two different WI. "Regular" WI (post turbo, IC...whether direct into the combustion chamber or pre-throttle valve) as a means to reduce temperature inside the combustion chamber, fight detonation by absorbing heat and reduce temperature, some moving power due to water to steam flashing, "catalyst" effect in flame propagation, etc., and pre-compressor WI, to make the compression more efficient by limiting temperature rise due to compression. Now, if you inject water pre-compressor and you still carry some water at the exit of the compressor, that water will eventually enter the combustion chamber and work as anti-detonation.

And you are right, steam inj does not make any good, it can't pull any more heat, steam acts just a one of the gas of the intake mixture.

lilfreddie

this water injection setup is very simple, I will have to get started on one for my car. As complicated as our cars are already its nice to simplify them to make them more reliable. SIMPLE IS BETTER! I really like the idea of not using an electrical pump, also for those concerned about putting the tank in the trunk and slowing the response time why couldn't we put a check valve in the air line near the turbo so that the tank always has a head pressure on it? good job!

Dudemaaanownsanrx7

iTrader: (23)

Yeah that is a good idea, you'll want the pressure switch on the manifold or somewhere other then the tank/pressure line if using a check valve. The only drawbacks are 1: each time after refilling the tank w/ water response will be slower. And 2: at times the pressure in the tank will be higher then the boost levels of the engine.example: You go wot and reach 20 psi, you then cut throttle and reapply only half throttle and the engine boosts 10 psi. The tank will still be at 20 psi which will supply more water then needed and might be a bit water rich, not only because of the increased water flow, but also because less air enters the engine at half throttle compared to wot even at the same boost. So in this case you lose a bit of the variable control thats already part of the system.

just startn

iTrader: (33)

Yea prety much lol. there isnt a "special way" around it. Just run a line like it should be normaly and that be that

ronbros3

about preturbo WI, some place i read a description of what may take place.

when atomized water particals reach the periphery of the maxed out compressor wheel, there is much higher temps than recorded from the whole air flow out.
this produces what is called SUPER heated steam,(super steam is invisable unlike normal boilin steam)also a shearing effect takes place in the steam molecules,heat is produced by the friction of the rubbing effect against each other.(maybe to the point of some actual molecular change)
then the quick contraction of the air/gas flow into the volute outlet, overall temp are reduced and density is increased