Water/Methanol Injection

[heysoundude]

My understanding is that in NA port-injected engines, that a little bit of water vapour/mist displaces some oxygen in the intake airstream, cools it somewhat, and absorbs the heat of combustion when it gets flashed to steam when the gasoline burns, but ALSO expands significantly more than the air it displaces would for a little boost in torque to make up for the loss of the fuel's energy.

I have a water induction system on my daily driver, a 2007 Buick Rendezvous with the 3.5L: (I can add a diagram/pictures if anybody would like)
It's a simple bubbler tapped into the PCV line between the front valve cover and the port behind the TB on the Intake manifold, with an aquarium bubbler stone at the bottom on an intake hose that breathes the hot air under the hood to better aerate the water supply, and a needle valve on the output to regulate the vacuum leak it introduces to the MAP sensor. on the MAP sensor signal wire, I've added a pull-down resistor (10-turn, 10kohm) to compensate for the vacuum leak. (so the ECU doesn't overfuel because of the extra oxygen from less fuel exhaust it sees at the o2 sensor)...the H2 component included in H2O might have something to do with things too.
using this in the summer, I get an extra 100+ miles out of my tank using about 4oz of water, and it doesn't feel any different to drive. I've never been brave enough to drain the 16oz of water in the 32oz bubbler vessel I use over an 18gal tank of fuel, but as long as I can offset the MAP reading, I suspect I'd improve on those 100+ miles...and to be clear, I only use distilled water rather than water/meth, which is why the summer-only usage (I live in a place that water usually freezes in winter)

that's my $0.02 - in my experience, It works as I have it implemented. pumps and nozzles and wiring seemed a bit over the top to see if it made a difference, and now that I see it does, I don't see the need to get crazy.

A few questions about water/meth injection...
Please excuse me gentlemen, I am German blood and I have to dissect everything, understand it. I don't like bolting things on and not knowing the fine details/science of the mechanisms.

What are you doing in PA. and what more does being German have to do with wanting to know in detail other than just wanting to be informed for good decision making regardless. No need to answer that.

You are asking of individuals what can best be served with more targeted research for articles on the subject, that way you can get a more thorough description than what most of us are probably willing to sit and type out. Here are a few links:

http://www.alcoholinjectionsystems.com/a40/Where-Do-I-Position-My-Water-Injection-Nozzles/article_info.html

http://www.max-boost.co.uk/max-boost/intake/WI.htm

Look for the calculator toward the bottom of the thread.

http://www.rbracing-rsr.com/waterinjection.html

[Schmieder]

There is a net effect with the addition of dual nozzles that is apparently equivalent to or greater than what the intercooler alone is offering on a street car if I read closely enough about the GN.

Of course I'm speaking of water/meth install on an engine as a benefit, not to treat an already knocking engine. It doesn't matter how well it works, several people on the Fiero forum still refer to it as a band aid partly because that's what Corky Bell called it decades ago.

A few questions about water/meth injection...

Under boost, where is the greatest amount of pressure? By the turbo compressor, throttle blade or just behind the intake valves? Reason I ask is placing the intercooler for increased efficiency. If there is greater pressure in the system closer to the compressor, I would place the intercooler closer to, like wise if it is closer to the TB the same

Also noting intake charge expansion areas. Knowing when a gas expands it cools, so any place during the intake there is expansion the air charge is cooled. Would a water/meth nozzle be best placed during intake charge expansion or compression?

Compression is obviously where the heat is introduced but spraying water/meth into a charge that is expanding should accelerate evaporation...thus accelerating the cooling action. Or would the vapor charge condense into large water dropplets when the intake charge expands?

In Short, where is the BEST place(s) to place a water/meth injector?
Should I polish my intake with a rough wall for boundry layer turbulence (just how fuel vapor is treated) to keep water in suspension and prevent wall beading?
Is there added benefit to have a dedicated water/meth injector per cylinder just like Fuel Injection? Or keep it just prior to the compressor?

Please excuse me gentlemen, I am German blood and I have to dissect everything, understand it. I don't like bolting things on and not knowing the fine details/science of the mechanisms.

My experience was that to get the greatest benefit of either system, use one or the other, but not both intercooler and ALC injection at the same time.

The intercooler would limit the effectiveness of the first spray nozzle for two reasons: it would show more psi loss flowing a mixture rather than dry air, and it would tend to condense the mixture, which would add heat back to the system. Granted the intercooler would drain off that heat, but if the mixture condenses enough, it would pool and create even more psi loss.

Leaving the intercooler in for safety, I don't know. What about just modding the Spark vs. IAT table?

I think if you work at it, you will come up with a good injection system. Of course, the key is timing the two nozzles and being able to vary their output rates. If I understand you correctly, you will cut in the second injector as the first one cuts off?

I haven't read anywhere that what you describe is what happens when the two are used together. I've read that boost pressure increased from its previous setting with the preturbo nozzle installed. The mixture evaporates inside the compressor housing and unless too much is being sprayed it doesn't pool at the intercooler. The preturbo nozzle is much smaller than the secondary nozzle, usually around .75-1 gph as opposed 3 or more, so the air is cool but not wet like what's going into the throttlebody.

The size of the intercooler also comes into play. If the air charge leaves the compressor housing at or close to ambient temperature there is no need for the intercooler, sort of what I implied in a prior thread, however, if injection is not being activated for several psi like 5 for instance, then the intercooler is beneficial in place in that it will probably be removing a considerable amount of heat from the unsprayed boost pressure, increasing overall power under the curve.

Starting with a good intercooler with less than 1 psi pressure drop for your boost level should still compliment the system. If the intake charge is being sprayed at a very low pressure you'll be refilling the tank frequently, something I don't want to have to do.

If my system is set to spray at 7 psi, I will need the intercooler because my datalogs show inlet air temps more than 212 deg by that time without the intercooler. With it temps dropped by more than 100 deg by that point which in theory is good for ~10% increase in power.

[AleroB888]

..................... Depending on how well it does that you may not benefit from an intercooler by the time the second nozzle kicks in to add its contribution to the combustion process. This depends on when you start spraying, the later the more beneficial the intercooler to the air passing through before injection.

If injection starts at 1 to 2 psi the overall cooling effect maybe equal to or greater than what the intercooler alone provides or at least made that way by the time you deduct for intercooler inefficiency due to drag/obstruction of the air passing through it.
That's apparently why some have found they no longer needed the intercooler and removed it altogether after the addition of a second nozzle.
A simple datalog of air temps with intercooler vs. dual nozzles and no intercooler could determine the need for the intercooler. ..........................

I will make it a point to test the theory once it's installed. I would run the intercooler regardless as a safety in the event of an injection system failure.

My experience was that to get the greatest benefit of either system, use one or the other, but not both intercooler and ALC injection at the same time.

The intercooler would limit the effectiveness of the first spray nozzle for two reasons: it would show more psi loss flowing a mixture rather than dry air, and it would tend to condense the mixture, which would add heat back to the system. Granted the intercooler would drain off that heat, but if the mixture condenses enough, it would pool and create even more psi loss.

Leaving the intercooler in for safety, I don't know. What about just modding the Spark vs. IAT table?

I think if you work at it, you will come up with a good injection system. Of course, the key is timing the two nozzles and being able to vary their output rates. If I understand you correctly, you will cut in the second injector as the first one cuts off?

This is a good short and to the point example of the dual nozzle benefits:

http://www.turbobuicks.com/forums/alcohol-propane-nitrous/80025-good-read-pre-turbo-injection.html

No,I meant compression.
It raises octane slightly also,but water doesn't compress-therefore you are raising effective compression ratio slightly which contributes to a higher cylinder pressure.

Sounds a bit confusing to me. The water alone displaces some of the air fuel mix resulting in a less potent mixture than water and meth combined. The heat causes the water to evaporate which in turn absorbs some of the heat effectively raising the detonation threshold to allow more timing advance I thought.

You can't compress liquid water (or gasoline) appreciably but that's not the state it remains in during the combustion process so unless there's a formula available for me to look at for a better understanding I don't believe that's correct since raising compression to a point will increase power output and this suggests adding water to the airfuel mix alone will increase power by increasing compression ratio.

Alcohol injection requires advancing ignition timing above normal timing to increase performance which its properties permit you to do. I don't believe from what I've read it will do anything for a properly running engine without doing so.

The new and increasing trend of dual nozzle (pre & post turbo) installs providing greater performance results is what sparked this thread. Done properly it makes a given turbo perform like a larger turbo by increasing its efficiency through cooling the air charge before it leaves the compressor.

Depending on how well it does that you may not benefit from an intercooler by the time the second nozzle kicks in to add its contribution to the combustion process. This depends on when you start spraying, the later the more beneficial the intercooler to the air passing through before injection.

If injection starts at 1 to 2 psi the overall cooling effect maybe equal to or greater than what the intercooler alone provides or at least made that way by the time you deduct for intercooler inefficiency due to drag/obstruction of the air passing through it.
That's apparently why some have found they no longer needed the intercooler and removed it altogether after the addition of a second nozzle.
A simple datalog of air temps with intercooler vs. dual nozzles and no intercooler could determine the need for the intercooler.

A difference in the range of 20 deg favoring the intercooler may not be significant at all when you consider each 10 deg drop in temp is worth about 1% increase in power and if there is at least a 1 psi drop in pressure across the intercooler you may gain more in time to reaching boost pressure and reduction in exhaust back pressure from removing the restriction.

I will make it a point to test the theory once it's installed. I would run the intercooler regardless as a safety in the event of an injection system failure.

[DefEddie]

No,I meant compression.
It raises octane slightly also,but water doesn't compress-therefore you are raising effective compression ratio slightly which contributes to a higher cylinder pressure.

[TiredGXP]

I think you ment it raises octane rather than compression, unless you are talking about lower temps increasing the density of the airmass.

I'll think about adding water/meth injection if I can't reach my boost HP goal with intercooling. With just injection, I'd be worried about running out of juice unexpectedly (things break/leak when you don't expect it), so my own preference is to keep an intercooler in the loop.

[DefEddie]

Water methanol does more than simply lower temps.
It also effectively raises the compression ratio a small bit,not to mention your adding a fuel source.
My friends dyno shop has had excellent results using it not only on forced induction vehicles but also on n/a type engines.
And of course smokey yunick years ago experimented and used it (among other things in ww2 planes) and he loved the stuff.
I like anything smokey did!

I plan to use water meth on the 3.1 tgp motor i'm putting into my fiero,along with an intercooler (and nitrous-nature's anti-lag!)

I, for one, have had better results with an intercooler system. I had been using an atomization system ahead of the SC (ahead of the throttle body, in fact) with pure methanol, and getting pretty good results. In 90 degree ambient temps at the track I could get 40 degree input temp to the SC, on cold days as low as 28 degrees (!). However, by the time the mixture got through the SC, the temps were still 22-40 degrees above ambient. By comparison, IAT's measured in the UIM with my intercooler range from 10-15 degrees above ambient (by the end of the track).

The previous owner of my intercooler had used a Snow Performance system on basically the same SC'd 3400 setup as mine, but got better results with the intercooler.

Super chargers for some reason tend to perform differently than the turbocharger with water/meth injection, at least the style designed for the 3800. Owners have attempted using water/meth injection with it and for the most part have obtained unsatisfactory results. I haven't read much if anything about its use with centrifugal blowers either. Also it's the dual nozzle systems that have allowed some to eliminate the intercooler due to the cooling effect taking place inside the compressor housing and again along with internal combustion benefits from the nozzle just before the throttle body. Hopefully I'll be able to post some meaningful numbers when it's installed in my car.

[AleroB888]

I, for one, have had better results with an intercooler system. I had been using an atomization system ahead of the SC (ahead of the throttle body, in fact) with pure methanol, and getting pretty good results. In 90 degree ambient temps at the track I could get 40 degree input temp to the SC, on cold days as low as 28 degrees (!). However, by the time the mixture got through the SC, the temps were still 22-40 degrees above ambient. By comparison, IAT's measured in the UIM with my intercooler range from 10-15 degrees above ambient (by the end of the track).

The previous owner of my intercooler had used a Snow Performance system on basically the same SC'd 3400 setup as mine, but got better results with the intercooler.

[DefEddie]

subscribing.

[abycat]

just read the subaru wrx forums they swear by it. i also have a venturi water meth setup and it works great. by the way only over 50/50 mix is flammable. and the atomisation is done by using 200 psi shurflo diaphram pumps.

Here is some excellent graphing data with pre and post injection and further confirmation that the Grand National guys were indeed using it in place of the intercooler indicating they were able to make more power substituting the IC with dual stage water meth.

http://www.aquamist.co.uk/phpBB2/viewtopic.php?t=559

Current thread discussing the above:

http://forums.evolutionm.net/water-alcohol-injection-nos/435472-intake-temperatures-pre-turbo-injection.html