Alcohol/water Injection
 

being in the process of building an Auxiliary Injection (AI) system for my FD i recently did quite a bit of research on the subject and thought it might be helpful to post my list of sources.

i recognize there are many on the board that are more knowledgable than i on the subject but in the spirit of attempting to make this site always more valuable to the user i thought i would share the following sites that i found helpful. obviously the list is not meant to be complete and i encourage all contributions.

BTW, generally the subject is referred to on this board as water injection (WI). since all of us may be pursuing different objectives and therefore may be injecting various alcohol derivatives, such as methanol, ethanol or isopropal alcohol i would suggest that the general topic be referred to as Auxiliary Injection (AI).


as usual, thanks to the Web, there is a huge amount of information/misinformation out there.... as in every other part of life positive results are achieved by making the hard and correct decisions among lots of options....

you want information on AI? try reading all of the 60 forum pages at TurboBuick! i believe that when considering AI there are far more similarities than differences between piston engines and our rotaries and the TurboBuick has had a long history w AI.

we all won't end up at the same place re AI as we have differing objectives. My objective is to make maximum hp under the curve on pump gas so i am going w 100% methanol and will be tuning so as to take advantage of methanol.

AI system equipment has come a long way in recent years and now offers a reasonable degree of safety so you can tune up for it's advantages.

Auxiliary Injection Tech Information

http://www.waterinjection.info/ must read

http://www.turbobuick.com/forums/forumdisplay.php?f=14 60 forum pages!!!!!!!!!!!!! excellent real-world tech

http://www.waterinjection.info/phpBB2/ 6000 posts excellent

http://www.alkycontrol.com/ FAQ learning center 30 key questions

http://www.aquamist.co.uk/ go to Resources…. Quite valuable

http://naca.larc.nasa.gov/reports/1943/naca-report-756/ 1943 govt white paper

http://www.snowperformance.net/ see forum


Vendors

http://www.alkycontrol.com/ my pick, racer, very experienced, elec engineer, first progressive controller

http://www.aquamist.co.uk/ super product, mostly water

http://www.aquamist.co.uk/sl/plist/frm-4-USD.html dealers parts list price

http://www.rotorsportsracing.com/per..._injection.htm AQ dealer good product info onsite

http://www.coolingmist.com/ rx7 background new progressive controller, breadth of good product

http://www.devilsownonline.com/alcohol/index.php message board, new progressive controller

http://www.enginerunup.com/ site currently down but good resources and products, you’’ have to check later…

http://www.snowperformance.net/ safeinjection++++ i may use this on my system

http://www.smcenterprises.com/turbo.htm turbobuick racer, realworld experience, progressive controller



DIY

http://members.aol.com/raydorman/ DIY

http://members.cox.net/stevemonroe/AlcoholInjMod.html DIY




Failsafe Systems

https://www.rx7club.com/attachment.p...hmentid=125197 post 21 radkins boost related

http://www.coolingmist.com/ see SafeInjection product flow related

http://www.aquamist.co.uk/ see DD2 flow related





(typical) Fuel Cell for Methanol/Alcohol

http://www.hunsakersports.com/shop/item.asp?itemid=76 fuel cell

while the board does have a number of members that are already using AI i hope to encourage greater understanding and usage as AI conveys huge benefits to the turbocharged engine rotaries included.

please feel free to add to this thread, especially after cruising the above links.

AI + Pump = Racegas...

howard coleman

It is far more effective to use more water than alcohol if you wish to maximize horsepower, especially in conditions where the car will not be exposed to freezing temperatures (the water may be drained during winter seasons). Water has a much greater specific heat (due to stronger intermolecular forces) than any alcohol and can absorb much more heat. There is no point in running a high/pure alcohol mix, since most of us do not operate our cars in the winter anyways.

Just some thoughts.

Info
 

Thank you for taking the time to gather all of that information. Much apprecaited.

-Rotary4tw

Wow a forum just for WI?!? Interesting

this is nice. i have been kicking this setup around for a while. since i had my ta. I was giong to get a turbo on that and use a methonol injection system on that. If it would not be considered dangerous for the rotary to inhale this setup i would buy it in a heartbeat.

Not true. Read his links.

The key with pure alcohol (methanol or ethanol) is you have to go big or go home. That's why most of the crappy initial run system users saw better results with water...their nozzles and pumps were inadequate for pure alcohol operation. If you don't spray enough alcohol to where you have to lean out the gasoline injection significantly then you're better off with water. Of course you're right on one thing...water pulls out more heat PER UNIT injected. Water can squash alot of knock while injected in very small amounts. The problem is you can only put so much water into a motor regardless of boost. After that point the motor starts to lay down & makes less power. Yes more boost will allow you to atomize a hair more water...but its not a significant amount. There is a practically vertical wall there.

Once you're injecting enough alcohol you're able to pull more heat out than you ever could with water. With alcohol you can run as much concentration as you feel like tuning for...theoretically up to the point wherel you're sustaining combustion on alcohol alone...mid-80's Formula 1 style. Pure Methanol + 1.5L 4 cylinder + 79.8 psi = 1300 HP. The only negatives to injecting massive amounts of alcohol is the cost for the methanol (3.60/gal around here) and taking the time to set up the system properly (an especially large reservoir, big nozzles, and a stout pump). Beside those things it takes a decent engine management system to be able to take full advantage of pure alcohol injection. You can get some gains with pure alcohol if you're running a simple piggyback setup but boost based fueling (speed density) and a wideband O2 with some sort of datalogging makes the combo lethal and capable of relatively big power on 91-94 octane.

You're the master of knowledge Howard. Again, thank you.

Or instead of injecting pure methanol you could just run the right octane in the first place. The only reason to inject alchohol is to get the benefit of variable octane. Maybe save some money over running race gas.

I would prefer to use straight water as detonation prevention/combustion enhancement and let my ECU handle fuel management.

On the street - pump gas, lower boost, and water injection.
On the track - race gas, full boost, and water injection.

ed

And spend alot more money doing it.
True.
Maybe? Try DEFINITELY!
Since when is water a "combustion enhancer?"

You can make more power with alcohol. That's a fact. I guess you would rather save the $5-6 every 300 miles that alchy would cost you. Have fun with that. You can buy a combo at a fast food joint or something.

HAHA six dollar burger... anyway whats your set up trevor? could u pm me prices u spent and stuff?

as i initially posted.... we may not all be pursuing the same objective, so we may each end up w different injectives.

in some situations water will work just fine, actually... fabulously.

in other situations meth is the ticket.

there should be NO argument which is best. they are each different in what they offer.

you read the links, look at your objectives and make a choice. many find a 50/50 mix works.

there is a tremendous amount of good info in the above links. i read the entire 60 pages from the turbobuick forum and pasted the relevant pieces into a file. the buick guys have been down the road and have done the learning curve thing.

we run turbo'd cars and dumping alot of excess gas into the combustion chamber, running only modest ignition advance and less boost than our uprated turbos can make on the street just isn't a fun way to live.

make mine meth.

howard coleman

The FD has a non-progressive 1/2 gallon SMC system under the hood with a 631 cc/min nozzle spraying 100% denatured alcohol above 6.5 psi. I usually run 14.5-15 psi on 91.

The Stealth used to have a SMC system just like the FD...I've ran it for the past 5 years. Only difference is it had a pair of 442 cc/min nozzles and sprayed at 10+ psi. 18.5-19.0 psi wasn't a problem on 94 octane. It'll do 11.7's like that all day long. The new setup is a progressive Snow system with a 1.75 gallon reservoir, 220 psi pump, and somewhere between 1091-1436 cc/min of Methanol (Snow's nozzle flow numbers are screwy) across two nozzles. I'm still in the middle of installing it:
http://members.cox.net/trevito/alchbox4.jpg
http://members.cox.net/trevito/alchbox7.jpg
The box was a pain to fab. Hopefully I'll make it up somewhere around 20-21 psi and 11.4-ish. 31-33 psi on C16 and 10's with the bigger turbos I just put on.

I am sorry, there seems to be confusion as to what water injection really does. The Aquamist system, for example, injects a mist of water to the intake air charge to cool it down. All of the water evaporates before entering the combustion chamber, as liquid in the chamber is a very bad thing for the engine. If alcohol is used in this case, it is far inferior to the latent specific heat of pure water.

I am unfamiliar with direct alcohol injection, as you all seem to be describing, into the combustion chamber. I do not see a reason for this other than raising the octane of the fuel you are using -- commercial petrol vendors often add in a mix of ethanol into their gasoline to raise octane levels. I suppose this is what everyone is talking about? If this is so, realize that alcohol is not nearly as combustible (distinguish this term from flammable..) as gasoline and although detonation would be reduced from the increase in octane, combustibility goes way down.

In other words.. yes, use ethanol/methanol in small amounts to raise your octane, but do not expect this to be a solution without a bottleneck. Chances are the gasoline you are using already has higher levels of alcohol in it already, and any more would only be reducing your horsepower. (Although this statement is not taking into account the net horsepower gain after the loss that might occur from an increase in boost pressure)

Aces...I understand you're trying to pick up some stuff about using methanol as a primary fuel.

Search the net for info on the pre-1988 turbo F1 cars that ran on straight methanol if you want to see what the fuel is capable of. This will get you started:
http://www.gurneyflap.com/bmwturbof1engine.html
I doubt even VP Import (which is 120+ motor octane and $20-23/gal) would be capable of keeping together a 1300HP 1.5L motor at 79.8 psi.

From the above links:
Water slows the initial burn but speeds up the end.

On the street, I'll stick with boost levels that can be supported by pump gas and water injection. I like that simplicity when keeping my tanks filled.

On the track, I like the simplicity of tuning my AFR with the ECU and I won't inject alchohol until I raise my boost above what race gas will support. Road racing works best with simplicity too.

ed

Sigh...not again. "All of the water" does not evaporate before entering the combustion chamber. While some trace amounts of vaporization may occur, if your intake temps were high enough to vaporize all of the water droplets (especially in the pressurized intake tract of a forced induction engine), you'd have much bigger problems to deal with.
Water injection does not cool the intake charge significantly. It does drop combustion chamber temps significantly, through the vaporization/chemical reaction of the water droplets in the combustion chamber.

Why is "liquid in the chamber a very bad thing"? The fuel in any intake charge entering the combustion chamber is comprised of droplets of liquid...

If you're referring to "hydraulic lock" due to the presence of massive amounts of liquid in the combustion chamber, actual combustion would cease long before it got to that point...

First off, thanks for all the great links, Howard.


Personally, I'm not quite sure how I feel about water injection. I understand that it will decrease combustion temps, and that this is helpful if you're searching for a lot of power. However, from what I read, you want a much lower volume of water (or meth) than fuel, which means your water injection system should be at least as accurate as your fuel injectors, which are cycled hundreds if not thousands of times per second by the ECU. My main concern is that most of the systems I've seen aren't very sophisticated: variable-flow pumps are a good start, but I would want my ECU controlling the amount of water (or methanol) being injected, in the same manner that the fuel injectors are controlled. Changing the voltage to the water pump just doesn't seem accurate enough in my opinion, and adding the exact same amount of water once the boost has passed a certain threshold just seems silly, without taking RPMs and exact boost pressure into account. At the very least, it's a waste of water/meth.


I'm not saying that alternative injection is a bad idea, but I would personally look into other means of keeping temps in check first. For instance, I think many FD's are experiencing localized boiling due to an inefficient cooling system design: the coolant pressure is too low, the water pump is likely to be cavitating, and the rotor housings don't have sufficient surface area to transfer heat to the coolant (Racing Beat, Rotary Power and other builders have been carving cooling fins in housings for years with good results). I'm planning on experimenting with AI in the future, but that there are a few other things that I would want to fix before adding another possible point of failure to our cars.



-s-

^people who run water injection aren't trying to lower engine coolant temps...

I don't think changing the voltage to the WI pump is a great way to monitor injection either.

The only company that makes a HSV ($250 a pop) that is capable of mirroring a fuel injector is Aquamist...that I know of, anyway. This is also the only way I would feel comfortable tuning for WI/AI

Not directly, but remember that the coolant temps are only part of a larger system. The goal of water injection is to keep combustion chamber temps in check, in order to prevent detonation. The combustion chamber is formed by the rotors and housings, so removing heat from the housings is one way to remove heat from the combustion chamber. In an engine without water/meth injection, the cooling system removes most of the heat from the metal engine parts, such as the housings and turbochargers. I'd actually prefer if my coolant temps rose (but remained safely below boiling) and my EGTs dropped, then that tells me that my cooling system is doing a better job of removing heat from the engine.


Water injection cools the combustion chamber from the combustion side. Granted this function can't be completely replaced by an optimized cooling system, but I think it's something that should be looked into before adding such a complex system as water/meth injection.

-s-

^good explaination, thanks for that.

however my bonehead statement is...an optimized cooling system won't allow me to safely run lean A:F, high boost and advanced timing on pump gas ;)

You do make a very good point, as every modded car should have a propperly running cooling system...and should not dive into AI and expect to make great power reliably

i agree w the point made that AI w a progressive pump does not offer a sensitivity similar to how we are able to tune our fuel w my Power FC and Datalogit.

it doesn't have to.

after setting/adjusting the turn on/ ramp and final amount of injective to a proper tune all AI has to do is be repeatable. and it is.

after tuning the AI to the point where you are happy you fine tune w 93 octane just as you would pre AI.

spend some time on the Buick link.... 3850 pound cars running 231 cu in pushrod 2 valve stock block motors running 25 to 30 pounds of boost on PUMP gas and making 800 flywheel hp... on meth. generally w no knock. without meth 18 psi is the limit and with knock.

again, many of us would be happy w water and that's fine but if you are looking for power...

howard coleman

Howard hit it on the head. The AI just has to be consistent and repeatable. Providing you have full control over the gasoline injection you can adjust that in very fine increments to arrive at the exact air/fuel ratio you're shooting for. If you do it right, once the tune is completed every time you pass thru that load/RPM point you will have the same AFR you had once you were done tuning.

Proof?

http://members.cox.net/trevorlj/552AWHP.JPG
The alchy came on around 3600-3700 on this pull. This a non-progressive setup. That means it came on full blast with 884 cc/min of denatured (90% ethanol - 7% methanol). That's a pretty large amount of fuel to introduce all at once. I have the fuel map in the computer set up to pull back the gas just the right amount at the same time the alchy comes on line. With a progressive setup the transition to alcohol operation would be even smoother. What's really funny is I run a piggyback speed-density fuel computer in my Stealth. It's not even a standalone. That pull was actually the first and only pull at 23 psi (before the kicked me off for another customer's appointment).

Although air to fuel ratio is fairly strict, the water to fuel ratio is a bit more flexible.

An alternative to a high speed valve is staged spray nozzles. Two nozzles can supply three different flow rates which can keep the water to fuel ratio within 25% of whatever you want. Three nozzles could be set up for 7 different flow rates to keep the water fuel ratio within 12%.

But I haven't heard of anyone who sells a controller that could do that even though it wouldn't be too complicated to build. Many standalone fuel systems have the extra outputs to do it.

Another drawback would be if you wanted nozzles in each intake runner. You would need a lot of nozzles.

But it could be fed with a standard pump and only a few low speed valves.

ed

Never thought about it that way...neat idea.

Okay, so to use a variable voltage AI pump controller, you cannot use an accumulator tank in the system, correct?..or is there something I'm not understanding???

question: what is essential to monitor to know when you are happy with an AI tune? EGT, Knock, power?

:offtopic: just a little, but how much could a fuel cooler reduce combustion chamber temps? Would this be a worth while addition to AI? Seems like you want the lowest possible starting point...

trevor,
did that sheet come from a rotary?