Diff. in tuning a 15wt%MeOH-water Vs. 50Wt%MeOH-water mix

[GotH2O]

15/85 mix:
got to lean out fuel to burn hotTER due to high in-cylinder cooling

50/50 mix:
got to lean out fuel due to the addition of more fuel/MeOH

What about the timing and boost?

The car is a 2.0L turbocharged mitsu evo.

just want to narrow it to either 15/85 OR 50/50 wt%. Please help.

Btw, the 15/85 mixture was chosen because the surface tension of water is very much reduced (effect tapers off as wt% MeOH increases) and I'm hoping that it will lead to better atomization and better distribution of water to each cylinder.

[Richard L]

It is possible to take some picture to show the difference of the two mix?

[GotH2O]

the decision is based on the paper titled :"Quantitative assessment to the structural basis of water repellency in natural and technical surfaces" - Journal of Experimental Botany, Vol. 54, No. 385, pp. 1-9, April 2003

Surface tension of:
100% water = 73.5 dyne/cm
10wt% MeOH in water = 55 dyne/cm
20wt% MeOH in water = 47.5 dyne/cm
50wt% MeOH in water = 34 dyne/cm
100% MeOH = 23.5 dyne/cm

factors affecting atomization: surface tension, density and pressure

@10wt% MeOH, surface tension of water drops 25%
@20%, 35.4%

I am trying to stay away from/use as little methanol as I can because there is already enough fuel from the injectors, and replacing gasoline with alcohol makes no sense (less heat of combustion from methanol). Also added cost for buying MeOH.

[GotH2O]

I will once i get all the fittings in for the system.

Originally Posted by Richard L

It is possible to take some picture to show the difference of the two mix?

[GotH2O]

i actually have a shurflo 100psi pump sitting around......just need to get from a 3/8MNPT to 4mm to use the aquamist nozzles

[Richard L]

I try to make sense of this, does higher surface tension gives better atomisation?

Richard

[JohnA]

Originally Posted by Richard L

I try to make sense of this, does higher surface tension gives better atomisation?

Quite the opposite, I'd think that high surface tension would give worse atomisation, as the molecules of the liquid would try to 'stick' together, wouldn't they?

GotH20 was kind enough to send me a copy of that graph, which I stuck on my website (thanks mate :wink: )
It confirms my experimental data that most of the surface tension benefits have been achieved by 20%. Given the increased safety of such a mixture, I tend to stick with it, as a good compromise