It's counter-intuitive, but often a 50/50 mix can have a more helpful effect than pure meth.

Methanol is incredibly good at absorbing heat on the intake side, much as isopropanol will feel very cool on your hand. However, it does not absorb a large amount of heat energy before it is evaporated compared to water. Water might not absorb heat as quickly as methanol, but it can absorb more before it is vaporized.

It's hard to get hard and fast temp data inside a cylinder in a particular engine with a particular setup etc, but the heat absorbtion of water in the actual combustion chamber can play a big role in keeping things like exhaust valves, sprak plug tips, etc cool and preventing pre-igniton. That benefit does not neccesarily show up in terms of detonation controll or IATs, but it might with EGT data.

Frankly its going to be a big help either way.

 

^^^^^

We need data, reports, analysis, something....

EDIT: How about a particular inter-cooled car running intake air temps between 80 - 120 deg. F where various injection ratios are used, and the maximum hp before the onset of detonation is recorded for each of the various ratios... Of course, for this particular test the total volume of the injected solution should remain constant.

Based on your screen name and signature, I'm speculating that you work for Snow Performance. A company with their reputation must have data available. Get that data and share it with the forum and you will earn kudos here....

 

Well it being that I do my own tuning (street), my funds are limited when it comes to dyno time. So it would be hard for me to collect data with the different mixtures. I could however show how the butt dyno feels but thats not an accurate way of measuring things, unless its day and night difference in power/feel. I could probably test out different mixtures and see if my knock gauge is showing up any timing retard, and try the different mixtures to see which produces the least knock, but again, it will be hard without a dyno to actually see the output, because say i have a mixture thats doing a good job with preventing knock or pre-ign, that same mixture could be robbing some power and etc...

 

Correct. I will see what I can find in the way of SAE data on that, and a test would be awesome. I dont suppose our intrepid thread starter would be willing to do some testing beyond just dialing in the system ?. In the meantime, that observation is based on two things:

1) The success we have had with 50/50 over the years.

2) Basic physics. Water's latent heat of vaoprization is far higher than methanol (473BTU/LB versus 970BTU/LB for water), which means that in a combustion process that without a doubt converts all the injected mixture from liquid to gas, you are absorbing more heat with the water cc per cc, and doing before the spent gases go past the exhuast valve.

Thats not to say higher meth content won't do a ton of cooling. It certanly will. Plus, another great aspect of that is that you can inject a much higher volume of pure methanol compared to say 50/50 water methanol before you "quench" aka kill the flame front. So a test where the flow rate was kept the same would actually be unfair to pure meth.

But one key reason we do not recomend pure meth is safety. Methanol has a very low flash point, and it burns clear. Dont take risks with it if you do use it. 50/50 is very hard to ignite by accident.

 

Sorry this took so long:

http://www.snowperformance.net/forum...pic.php?t=1714

Lots of good info on the subject at hand in terms of what fluid to use.

 

That is very good information, thank you for that link. I think I am going to stick with using water in my mixture.

 

Not complaining, but that's not the hard data I was hoping for. Speculation from experience is nice, though, and thanks for that.

Ideally, I'd like to see back to back dynos with different concentrations of fluid and robust data logging EGT, AIT, knock counts, whp, boost, afr etc. I can't believe no one has gone to the trouble. I haven't been able to find solid data (for testing within the last couple decades)...

 

I don't dispute the basic physics. I concur that the water's latent heat of vaporization is higher than methanol.

The issue is the NACA data, as well the information provided by others who themsevles have done the comparison. As noted, in the NACA data the gap in performance between straight water and the 70/30 meth/water ratio increased significantly when the intake air temperature was changed from 250 deg. F to 150 deg. F. Taking that data, and extrapollating it to the intake temperatures that we run, the gap in performance at inhibiting knock will increase even further. There is more happening than we can predict based on the latent heat of vaporization and the octane rating of the meth. What that is, I don't know, but the data is what it is, even though it seems counter intuitive. Clearly, more testing needs to be performed, but that will take a lot of time and/or cost a lot of money. It's very hard for an individual enthusiest to justify that. For a company that makes its livelihood on meth/water injection systems, well, it seems a little more justified...

 

We will have something just like that soon, but its hush hush and for diesel anyway.

With gasoline apps like this, you open a whole can of worms about how each mix is tuned and how much you inject.

For instance, you can over-inject massively with pure methanol, and not really have mis-fire or bogging issues because alcohol in general is very forgiving of rich AFRs. To the point that you can have puddling and wash down and not know it, but probably produce remarkably cool temps for a few dyno runs.

I will see if we can get some really lab quality testing done somehow with pure H20, 30/70, 50/50, 70/30, and pure meth. Might take awhile though.

 

^^^^

Awsome!!!

 

+1. That type of data posted on your site would draw a lot of visits your way.