this is the way forward for us rotor heads
http://www.autospeed.com/cms/article.html?&A=0115&P=5
you got to read this. those yanks are gettin big bhp with big turbos and lots ov boost on stock engines.
reading about the w,i and its working well.
http://www.teamfc3s.org/forum/showthread.php?s=&threadid=9692&perpage=25&pagenumber=1
Sure seems to be the way mr large member ;)
Can\'t believe how many people have bought these kits the last few weeks! John Helps has had it for a while now, mine goes in next week, Phil Gooriah I think is going for it, even OJ has just bought a kit!
Everyone here is think has bought/ is going for the aquamist systems:
//www.aquamist.co.uk
I reckon these are probably more vital on a rotary than they are on boingers!
Regards
Max
front rotor gone
one seal missing both its ends, and embedded in the rotor
and a very hot turbo pack and rear rotor
I\'ll never learn ;)
Here\'s a couple more for you to get confused with. You never have enough information.
http://www.turbomirage.com/water.html
This is the kit that John Helps is running (http://www.imoc.co.uk/users/upload/Water-Injection-Manual.pdf)
I myself like most of the others will be running an Aquamist 1s system.
Dan
PS. Max have most of the sizing cut out now, just need to get the alloy cut to size. :p
ooops! Sorry Dan, forgot about you on the list of people fitting water features ;)
sorry, injection.....
Bit worried about injecting water before the turbo! Most sources say not to do this. The theory being that the turbo(s) can suffer from thermal shock and the water can cause corrosion, but could be bull??
See Dan?? I didn\'t even mention the tank ;)
Regards
Max
And to think David Vizzard was playing with water injection in the 80\'s
True Mike, its been used plenty in the past on vehicles and aircraft even, but never really went mainstream for some reason.
Bit like skateboards, its coming back........
Regards
Max
it says in that first link about the prob with going in before the compesser is it serates the turbine. i\'ll be getting this on my car. and i\'ll go in just after the comp wheel i think.id be interested how you get on with you rone. let us all know what you do. it seems that once its on you can crank up the boost,, nice
the first time i saw w.i was on an old cozzie. i thought that it must just be something that the owner was trying ,and that water in the combustion would hydralic and bend the rod\'s. it seems that it is all good after all:D
OK, follow the link below and see what fitting jets in different locations where does, and why they are put in thos locations.
Info Here! (http://www.aquamist.co.uk/cp/sys2/techsys2/diag/fig10.html)
John\'s is locationed jsut after \'C\' on the joing from the IC to the main inlet arm pipe. Samco make a pipe that has a side feed which was designed for this perpose, sadly its originally for a boinger, but as the boinger is of the performance varity I\'ll let it pass. (But some will give me some stick for it! So :p)
Dan
QuoteOriginally posted by maximtaylor
front rotor gone
one seal missing both its ends, and embedded in the rotor
and a very hot turbo pack and rear rotor
Found the big bit that was missing earlier :-)
All plates looked ok (but what do I know!)
Turbo pack looked a bit tinted but in good nick, no cracks or play (but again, WTF do I know!)...
Be happy mate - the other one he took apart today was WASTED - lucky to get a rotor and the front plate for rebuilding!
R.
I will probably go just post intercooler like John with mine me thinks! As I have hard pipes from intercooler to elbow, I was going to tap in there.
Thank you for your prognosis Dr Rich ;)
We will see what the consultant (Geff) says tomorrow!
Regards
Max
OK - has anyone put the water injection in a stockish laid out engine bay?
WHERE DID YOU PUT THE PUMP???:confused: :confused: :confused:
cheers
OJ
look here:
http://www.mazdarotaryclub.com/forums/showthread.php?s=&threadid=1276
not entirely sure that\'s a stockish engine...
I know where to put it, and the answer involves hard currency OJ ;)
If the engine bay looks full, and you still have your battery in the front take a looksie inside the nose, just under the bonnet latch. There is a huge space under there with a ledge to secure the pump onto. Only problem is going to be getting tools in there to tighten the fixings!
The holes could be drilled from underneath
Haven\'t done it yet, but I think this is where I\'ll put mine.
Regards
Max
yeah, i did see that, but figured if there was somewhere else, that may be more convenient... I might just bolt it to the underside of the bonnet!! *grin*
Cheers sweetie!!
((Now why can\'t rich be more like max - nice accomodating and helpful... Max, You aren\'t a moderator either are you... You know, I just got offered moderatorship on another thread, and then it was taken away from me straight away. But they still have Rich as a moderator and not us... strange, isn\'t it))
Iwan, the WI kit that Miguel is running is not the ERL system, and I wouldnt want to fit the ERL pump there due to heat from the turbo\'s.
US Non ERL Install (http://www.rx7club.com/forum/showthread.php?s=&threadid=202871)
You could always mount the pump in the boot, but they do make a fair bit of noise and not something I would want.
Dan
erm!
Actually I am a FDUK moderator now!
Sorry mate, its you v moderators now - you\'re on your own.
:wave
Max
A few notes on water injection:
Injecting at the compressor is the best place to do it. It moves the compression from being adiabatic to nearly isothermal. This is more efficient. More efficient =more HP. A fine mist, as a misting nozzle will give will not hurt the compressor blades, but if you are worried then inject into the scroll of the turbine; most of the compression occurs in this area anyway.
To get the most from the technique you should ditch the intercooler altogether and just use water for the charge cooling. This is against the grain for many and very few tuners have done this, but the theory stacks this up thermodynamically (and tuners get to make £££ selling aftermarket intercoolers). No IC means more power again :-)
Water itself is a great thing. As well as cooling and providing knock protection it is actually very active during the combustion process and helps speed certain reactions along. I can share the chemistry if anyone is really interested.
My favourite method for WI is to use manifold pressure to pressurise a tank of water connected to a misting nozzle spraying into the compressor. Bar a solenoid to turn it on at a preset boost the only moving parts are the air and the water. Because it runs off boost pressure water flow increases with boost as you want it. And its cheap. I like cheap :-)
A handy little toy is http://not2fast.wryday.com/turbo/glossary/turbo_calc.shtml . It allows you to play around with water injection and see the effect that is has on power. It does not prevent silly numbers being entered, so you have to think a little
Bill
Bill,
I\'m following what your saying and interested to learn more, so expand further if you don\'t mind. How do you see the compression being nearly isothermal? (digging up my engineering degree times now!) The compression is done in the housing, so are you saying inject before the housing? Surely it would be better to cool the charge immediatly after the compressor, after the work and heat energy has been put into the air, where the benefit of WI will have most effect?
I\'m confused as to why you say no IC means more power. I understand that it will reduce lag, but can you explain this in a thermodynamic sense? and also explain the chemistry your talking about and how it can help speed up the reactions your talking about.
Cheers, interested,
Mike
Sorry for reply lag. Auto mailer seems to be not doing its stuff at the moment.
First off the cooling. If the water is present as the compression occurs then it cools the air AS it is compressed rather than compressing (and therefore heating and reducing the density) followed by cooling. I\'d have to go up in the roof and make my head hurt to be able to get the proof, but enough friends of mine who still do remember their thermodynamics concur that it is a more efficient way of doing things. If you look at it in CFM terms with WI at the compressor you are gettting the same CFM, but at higher density.
On the intercooler side, there are a number of things to look at. Firstly pressure drop. Even with a big IC there will be some losses. It may be as low as 1PSI, but that is one pound less boost . Secondly you have the \'interwarmer\' syndrome. when you are off boost or at low boost the intercooler as often as not adds heat rather than removing it. Its more an efficiency thing rather than power, but efficiency is good.
ON the water in combstion side, here are some notes from a friend on the subject:
----------
During combustion - water - H2O ( present and formed ) is extremely active in
the oxidation of the hydrocarbon. The predominate reaction is the following:
OH + H ==> H2O
H2O + O ==> H2O2
H2O2 ==> OH + OH
Loop to top and repeat.
The OH radical is the most effective at stripping hydrogen from the HC
molecule in most ranges of combustion temperature.
Another predominate process is the HOO radical. It is more active at lower
temperatures and is competitive with the H2O2 at higher temps.
OO + H ==> HOO
HOO + H ==> H2O2
H2O2 ==> OH + OH
This mechanism is very active at both stripping hydrogen from the HC and for
getting O2 into usable combustion reactions.
Next consider the combustion of CO. Virtually no C ==> CO2. Its a two step
process. C+O ==> CO. CO virtually drops out of early mid combustion as the O
H reactions are significantly faster and effectively compete for the available
oxygen.
Then consider that pure CO and pure O2 burns very slowly if at all. Virtually
the only mechanism to complete the oxidization ( Glassman - Combustion Third
Edition ) of CO ==> CO2 is the "water method".
CO + OH ==> CO2 + H
H + OH ==> H20
H2O + O ==> H2O2
H2O2 ==> OH + OH
goto to top and repeat.
This simple reaction accounts for 99% + of the conversion of CO to CO2. It is important in that fully two thirds of the energy of carbon combustion is released in the CO ==> CO2 process and that this process occurs slow and late in the combustion of the fuel. Excess water can and does speed this conversion - by actively entering into the conversion process thru the above
mechanism.
The peak flame temperature is determined by three factors alone - the energy present and released, the total atomic mass, and the atomic ratio - commonly called CHON for Carbon, Hydrogen, Oxygen, and Nitrogen. The chemical reactions in combustion leading to peak temperature are supremely indifferent
to pressure. The temperatures and rates of normal IC combustion are sufficient to cause most of the fuel and water present to be dissociated and enter into the flame.
As can be seen above, water is most definitily not only not inert but is a very active and important player in the combustion of hydrocarbon fuel. Ricardo and others have documented that under certain conditions ( normally supercharged ) water can replace fuel up to about 50% and develop the same
power output, or that the power output can be increased by up to 50% addition of water. This conditions were investigated by NACA and others for piston aircraft engines. It is important to note that these improvements came at the upper end of the power range where sufficient fuel and air was available to
have an excess of energy that could not be converted to usable pressure in a timely manner.
--------------------
What the above actually means is that WI, when treated holistically as part of the system rather than a bolt on at the end gives you more power for less fuel, which can\'t be bad.
Bill
wow (http://smilies.networkessence.net/s/cwm/cwm/eek2.gif)
lol i followed the last paragraph, and thats summed it up for me :D
Thanks for that Bill, answers some of the questions I had, but opens up many more, so I\'ll look into it further if and when I get time - interesting to apply engineering principles to such things, but I seem to have forgotten a lot since my studies.
Was kinda following the chem bit, but got confused on...
"consider that pure CO and pure O2 burns very slowly if at all"
I dont know about Carbon Monoxide, but I always believed that pure oxygen (O2) is highly flammable. Its the life blood of an IC engine as IC engines basically burn air with the aid of a small amount of fuel (in comparison).
Anyway, further investigation needed. Will post if and when I find anything else.
Mike
QuoteOriginally posted by Mike
Was kinda following the chem bit, but got confused on...
"consider that pure CO and pure O2 burns very slowly if at all"
I dont know about Carbon Monoxide, but I always believed that pure oxygen (O2) is highly flammable. Its the life blood of an IC engine as IC engines basically burn air with the aid of a small amount of fuel (in comparison).
From what I remember O2 doesn\'t burn (isn\'t flammable) in it\'s own right but is part of the reaction. i.e. adding alot of O2 to normal combustion will ake the combustion faster (explosive in certain circumstances).
Under most circumstances adding O2 isn\'t safe or affordable but adding a component to the reaction that gives up it\'s O readily will increace the combustion.
I\'d guess that H2O is quite happy to give up the O part in the combustion process although this is counter-intuitive as H2O is very stable under normal temps and pressure and inhibits combustion.
Iain
Look at it another way. Complete combustion should end up with CO2 and H20. Of course it never works that way. Now reaction with oxygen is called \'oxidation\', its just that as we discovered fire before oxygen we prefer to call it burning. Same process though.
The early parts of the reaction, when things are very hot and at very high pressure tend to promote the reactions that produce CO. This CO needs to be oxidised/burned to make C02. Without WI the water produced in early combustion phases jumps in to help this. However this happens late on in the combustion, resulting in less power being delivered to the eccentric.
With WI you have excess water available near the beginning of the reaction which speeds things up, so that the energy released at a more beneficial time to transfer into the eccentric.
Bill
Here is a discussion that the US guys are having. (http://www.nopistons.com/forums/index.php?showtopic=25011)
After a couple of pages two guys find they dont like each others point of view/idea\'s, but they settle down and it gets back on track.
I will also try and find the thread that is going on with the RX7Club forums.
Dan
What a funny forum nopistons is. That Dragon really ought to leak off some testosterone and pick up a textbook. If only people put their brains back into gear and thought rather than this chest beating \'you know shit because you only have 300HP\' rubbish.
Bill
Hi Bill and all,
I think that the reason that the water injection makes more power for less fuel is that as you lean out any engine it makes more power as the flame front is more efficient and not dampened down by excess fuel to prevent detonation.
Without the water injection the flame front is less stable in this leaner condition and so can move too quickly through the combustion chamber which can lead to detonation caused by the pressure build up from this front moving too fast towards pockets of unburned mixture and preigniting it.
The water enables the flame front to be better controlled with leaner fuel ratios as it slows the combustion down and enables it to be controllable so that the flame front travels slower.The water absorbs some of the heat energy in the combustion.
Remember that lean makes more power than to rich but is more volatile. With water injection you can run leaner as you are no longer relying on the fuel to slow down the combustion process to control detonation.
Also the water has to expand in order to absorb the energy that is being produced by the leaner mixture of fuel and so in turn the water in a more controlled way is producing a rising rate of pressure in the combustion chamber which also drives the rotor or piston.
To sum up less fuel means more power with instability,water added to control the instability,water has in turn to expand and thus provides pressure in the combustion chamber which also makes power.
I hope that this is a little easier to understand.
Kind regards
Carl:)
I forgot to mention the cooling of the intake charge temp by water injection too, as it would mean that a denser mixture is going into the engine so more charge means more power too.
Kind regards
Carl
Hi Carl,
Partly. You also have to factor in that the latent heat of vapourisation of water is much higher than petrol, so during the compression stroke more cooling of the intake charge will occur for the same mass of liquid injected. So you get a double benefit of more air getting in AND less work done in the compression stroke.
Added to that there is the knock supression as you rightly say.
Then there is the improved combstion efficiency.
haven\'t got my text books to hand so can\'t check if the superheated steam adds anything significant to the BMEP.
Oh and your EGTs are lower. If used correctly this can become a benefit as you can setup your turbo so that it spools up early, but use the Wi to prevent melting your blades at the top end.
OR we can just say WI is very good.
QuoteOriginally posted by bill shurvinton
OR we can just say WI is very good.
That\'s me sold then :)
R.
Bill,
What magic number do I need to change to make that turbo calc. look like a rotary? If I put in 1.3l, then it makes about 100bhp, not 200+. Very interesting thread btw...
Sean
Carl,
you beat me to it. I was typing whilst you were posting :-)
Sean. I tend to set it to 2.3 litres as that works well as this is the effective air injested over 720 degrees.
Please not that the calculator requires you to be thinking. It won\'t stop you putting an AFR of 2:1 in and getting huge HP.
Bill
Nice explanation lads :)
OK, so:
1) We tend to run rich, as part of reason for this is to help cooling combustion, therefore more steady flame front etc.
2) Without water injection, I tend to run about 11:1 air/fuel ratio.
3) The water injection kit I have is solely boost activated (10 psi kick in). And will inject the same quantity of water whether running 4k revs, or 6k revs. But more air will be flowing at 6k revs, so the ratio of water to air will drop....
Follow so far?
Now:
a) what a/f should I be aiming for with water injection, bearing in mind that water / fuel ratio will vary at different revs because of 3) above!!!!
b) The aquamist advice says aim for about 10% water to fuel quantity used, but I have read that up to 30% water to fuel can be used - this would mean HUGE water injectors!!
Should I just tune on the basis that w/i is not fitted, ie 11:1 a/f ratio, then use w/i solely as a preventative measure? Or lean off to about 12:1, or more?
I think I should be cautious.........
Anyone fancy sponsoring my engine ;)
Regards
Max
Dont know about most of what you have just put up, as I need to learn it myself.
I would map on the basis of NO W.I. then add it for some safety.
Dan
QuoteOriginally posted by Carl
I forgot to mention the cooling of the intake charge temp by water injection too, as it would mean that a denser mixture is going into the engine so more charge means more power too.
Kind regards
Carl
This wont actually happen. The reason water injection increases power is because it allows you to run more boost, leaner A/F ratios and more advanced timing. if you put water ona a car and dont change anything it will not be more powerful, it will proberly be abit slower.
Ross,
Notice that this comment I made was in addition to my previous comment.
Hope that this makes more sense with that in the frame.
Kind regards
Carl
No Carl is dead right. If you look at it from a thermodynamic perspective, a water mist WILL increase the density going into the chamber allowing more charge in. But it must be finely atomised, which is why injection at the compressor itself is the best way to do it.
All the theory behind this was worked out some 65 years ago by the likes of Sir Harry Ricardo.
Its the same reason some cars love damp air and run best just after a rain shower (when traction is at its lowest). can\'t win em all.
Bill
No I have to disagree, WATER INJECTION ALONE WILL NOT INCREASE POWER. Even Aquamist admit it, and they make a living form selling the kits! This is a quote straight off their site- "1. My turbo car runs standard boost, would water injection increase the power output ?
Water injection will not increase the power normally."
I have also read something about the water obviously taking up space that would have otherwise been fuel therefore this cancels out the benefit, unless increasing boost etc.
I agree in heart with this statement Ross, but most cars dont see the intake temps that the rotary does.
I fitted up today my gauges, and was watching the intake temps on the way home.
Cruise was between 35-40 when making progressionit went up to around 65-70. So by making the intake temps cooler, could only help with this.
Dan
If you want to believe the aquamist website fine. Aquamist make fine pumps.
However, the ideal gas law and the works of Ricardo, Glassman, Heywood, taylor, NASA and the other \'greats\' of internal combustion research do not agree.
I\'ve done the sums and, when I finally get around to building up a turbo engine, I won\'t be using an air/air intercooler. However, like most things I do in the automotive area it will be pretty much a one off, as the aftermarket doesn\'t cater for the way I like to do things. But I wouldn\'t recommend this to anyone without a good grounding in the associated thermodynamics.
Bill
Aquamist make a living from water injection, they would be the first ones to admit it if it increased as it would increase sales.
I view water injection as heat absorber rather than an charge cooling tool.
Absorbing heat IS charge cooling, so I fail to see how the distinction matters to the incoming air.
As for Aquamist they have to tread a careful line. they cannot afford bad publicity so they are using a conservative approach and targeting a specific market for high boost turbos, who will pay a high premium for something that can be built for under £100.
WI has been proven to work very nicely on NA engines, and there are technical papers to prove it, but you won\'t get aquamist saying that on their website, and they certainly don\'t have engine research facilities along the lines that MIT have.
Still sceptical? Load up the turbo calculator and play around with different positions for WI and see how the maths drops out. All my comments are based upon sound and proven physics.
would it be possible to inject water at more than one point, say before the compressor for the isothermal reaction, and again post intercooler to cool charge again.
Or is this overkill/not possible/better just to remove intercooler.
Also what are the benefits of using methanol in a WI system, can you only use a methanol mix when injecting after the compressor or is it ok to use it before.
cheers
Andy
ah, another question. If you were to dump the intercooler and go solely for a WI cooling system, would a boost activated system suffice or would you needed it mapped to something different, ie revs, injector duty, inlet temps, etc.
Haved heard the Motec ecus have a feature for water injection? dont suppose the PFC\'s do:) ?
It might be worth you having a good long search for your answers on these forums (http://www.waterinjection.info/phpBB2/).
Bill might even like to go on there too. ;)
Fish
ah, cheers fish :) never realised there was a water injection forum :D i\'ll have a hunt
What do you mean \'might\'. If you look carefully I post on that site.
Problem is that is it more an advertorial for aquamist than an attempt to look at the science behind WI. Aquamist make good pumps, but are not that hot on combustion thermodynamics. A couple of the posters actually understand what is going on though.
Andy: Multi-point injection is THE way to get the maximum benefit from WI. Wouldn\'t be too hard to mod up the code on a megasquirt to be a dedicated WI controller.
The point of methanol (or acetone, or ethanol, or a mix) is that Daltons law of partial pressures states that each gas involved has a seperate saturation pressure. This means that, for each fluid you add, you get a seperate chunk of cooling. Water is used as a base becuase of its huge latent heat. But a mix of water, methanol and acetone seems about ideal.
Thanks Bill, so a system with no intercooler, injecting a water/metahnol/actone mix pre and post compressor would be a good set-up :)
How hard would it be to set up the pre compressor injection so that it does not do damage to the turbo, would it be a trial and error type installation
Yup.
If you are really worried about the turbine then drill and tap the scroll and inject there. Nearly all the benefit form scroll injection.
Bill
.
Having trouble registering on W/I forum, so thought id post this query up here.
I know theres certain guidelines relating to position of the components, ie, pump no more than 1 metre from battery, but havent seen any regarding pump/tank distance from the actual water jets.
Would there be any problems with having the pump, battery and water tank all located in the boot?
Short answer is, it depends.
If you are using an aquamist, then you effectively have to get the system primed for action, or you will have a considerable latency before the water starts to flow. Nothing that you cannot easily circumvent though.
Other systems have different ways of working, so the latency varies.
Bill, whos been pimping there wears in PPC then this month.....? ;)
Toying with seeing if journalism will pay the fettling fund.
Out of interest (and waaaay off topic for this thread, so sorry) will your ECU\'s run a 13B? I\'ve got one going spare, and I\'ve also got a white 3 wheeler Bond doing nothing...can you see where I\'m heading.... :cool
Quite a few 12As and 13Bs and a 26C running without issue. True split timing has not been implemented yet, but that\'s entirely my laziness in getting the code completed. Those running it have yet to miss adjustable split in NA installations.