Water/Methanol Injection

[Guest]

I'm really damned impressed it didn't start knocking when the afr's went into the 14's. That water injection must have really helped. Hope to hear the results with the better fueling soon.

I've been doing quite a bit of reading on water/meth injection and aside from the traditional install benefits there's more to be had with dual water/meth injection by adding an additional injector just ahead of the turbo although this is an S/C engine. It pre cools the compressed air by evaporation inside the compressor housing for added air density in addition to what occurs just ahead of the throttlebody and in the combustion chamber.

There has been concern about compressor blade damage but it has been proven that as long as the mist contains less than 18 micron droplets there's no problem. This requires the injector nozzle to be placed close to the compressor blades (inches) for a direct path because it prevents the puddling that occurs when a long indirect distance is present allowing for large droplets to develop on inlet plumbing and then hit the compressor blades. It's also less likely to happen in that circumstance when a water/meth mix is used instead of straight water due to a lower specific gravity.

I know they're not exactly the same principle wise but look what it does for the little diesel engines:

http://forums.tdiclub.com/showthread.php?t=209796

and here's a GN user that's in progress:

http://www.turbobuicks.com/forums/alcohol-propane-nitrous/78800-preturbo-injection-test-run-setup-2.html

The most impressive point comes about when you're making a lot of power off a small amount of boost and when you can significantly increase performance on the same amount of boost. We use a lot of old technology standards when addressing performance, but engines built 10-15 yrs ago are not as efficient nor the metals back then as strong as what we have now. We still use the same bsfc numbers in our calculations that were used on those engines and that can't be right given the hp/litre ratios we have now.

Some members on the Fiero forum refer to water injection as a cheap band aid. How redicuolous is that considering the results it produces at such an exceptionally low expense.

[robertisaar]

Some members on the Fiero forum refer to water injection as a cheap band aid. How redicuolous is that considering the results it produces at such an exceptionally low expense.

while it has good results, it depends on how it's used.

if someone is having a lot of fuel leaning/detonation issues and figures water/meth injection is the answer, it's wrong. they're fixing the problem by adding another variable. simplicity is our friend.

someone who CANNOT fit an intercooler, cannot fit a large enough intercooler, or NEEDS the extra temperature drop and cannot achieve it in another fashion, that's a correct application.

[Joseph Upson]

while it has good results, it depends on how it's used.

if someone is having a lot of fuel leaning/detonation issues and figures water/meth injection is the answer, it's wrong. they're fixing the problem by adding another variable. simplicity is our friend.

someone who CANNOT fit an intercooler, cannot fit a large enough intercooler, or NEEDS the extra temperature drop and cannot achieve it in another fashion, that's a correct application.

Look over the Grand National link, the dual nozzles are working so well that he has removed his intercooler and that car has plenty of room for a large one. The air is being cooled twice where an intercooler only does it once. The best an air to air intercooler can do is get you closer to 100% of ambient temps with some restriction. Water/meth on the other hand apparently goes one step further than that by providing at a small cost to none if you use water, an increase in octane rating in addition to reducing inlet air temps and increasing boost due to the quenching effect as opposed to the loss in boost you would get from restriction of air flow through an intercooler.

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.

[robertisaar]

i would still have an I/C, even with the mention of a backfire lighting a pool of water/meth stuck in the IC even though the chances are slim to none considering the heat and airflow.

it never hurts to have colder air in a boosted application. the restriction an IC is can't hurt more than it helps, so long as it has sufficient airflow.

it's almost possible to cool it down to ambient if you use two or three stages of water/methanol and a good, well-thought out air-air I/C.

as for the fiero forum: same effect that people have when reading religous texts, just people interpretting it differently. to me, when i read maximum boost, corky is saying that water injection is a poor excuse for proper fuel tuning. that's what i get out of it anyways.

[Joseph Upson]

i would still have an I/C, even with the mention of a backfire lighting a pool of water/meth stuck in the IC even though the chances are slim to none considering the heat and airflow.

it never hurts to have colder air in a boosted application. the restriction an IC is can't hurt more than it helps, so long as it has sufficient airflow.

it's almost possible to cool it down to ambient if you use two or three stages of water/methanol and a good, well-thought out air-air I/C.

as for the fiero forum: same effect that people have when reading religous texts, just people interpretting it differently. to me, when i read maximum boost, corky is saying that water injection is a poor excuse for proper fuel tuning. that's what i get out of it anyways.

It is very rare and with a properly sized nozzle highly unlikely given it is pretty much evaporated by the time it leaves the compressor. The system would have to be pretty poorly setup to allow any puddling ahead of the intercooler given air moving past any puddle is going to have an evaporating effect.

From what I've been reading water/meth will provide equal to or more performance increase on the same setup as a proper inter cooler. I read on snow's forum where water/meth injection is offering as much or more benefit by itself than an air to water intercooler which has the potential to provide greater than 100% cooling efficiency according to a couple of race car owners on the forum who are using it in place of their air/water intercoolers.

I have a front mount intercooler in my Fiero and I'm at about 90% efficiency. I'm sure my water/meth kit will provide greater benefit than that with a combined cooling effect and octane boost with a single nozzle. I'm going to install an additional temp sensor ahead of the intercooler and datalog temps under boost before and after the intercooler with the use of dual nozzles.

If the temp difference is negligible then the intercooler would only serve as a backup in the event the meth system failed and would also reduce efficiency due to the 1 or so psi lost due to resistance through it.

I would be able to eliminate additional intercooler related plumbing as well as recover the lost boost pressure through the intercooler that results in more exhaust back pressure to reach the desired boost. I might run a solid meth injection system and no intercooler if the results prove correct.

[TiredGXP]

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.

I was kind of surprised at his attitude on water injection. Floating around the net somewhere is a pretty good engineering paper describing the development and testing of water/alcohol injection for use in aircraft engines during the second world war.

The benefits seemed to be quite plain.

[Joseph Upson]

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

[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.

[DefEddie]

subscribing.

[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.

[Joseph Upson]

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.

[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!)

[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]

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.

[Joseph Upson]

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.