System recommendation for direct port evo ix

[rudyevo9MR]

Learning alot...thanks.

From earlier posts, given the speed of the air in the intake, even if the water / meth mixture is 'centrifuged' out of the air stream onto the walls of the intake, would the air flow cause it to evaporate and add same knock suppression/ higher octane benefit?

[rotrex]

The Methanol still will act as fuel as it rapidly evaporates in the cylinder. A significant fraction of the water will enter the cylinder in big drops and essentially do nothing.

[rudyevo9MR]

What's the phase relationship when water and meth mix?

Will the meth evaporate out of the mix whilst in the intake..leaving water droplets...and/or will the act of evaporation also cause some of the water to change state from liquid to gas or break it up into finer liquid particles?

Asking to learn...not trying to be difficult...many thanks rotrex

[rotrex]

no, they both will evaporate about as fast as their vapour pressure at the present temperature and concentrations of already evaporated methanol or water respectively will dictate.
There is some influence on the overall evaporation rate due to some physiochemical effects like azeotropic effect, change in surface tension, evaporation vs. diffusion to the droplet surface as viscosity also changes nonlinearity with the mixing ratio etc, but for the big part, methanol will evaporate very fast leaving mostly water behind in the liquid state. Due to evaporative cooling, the cooler droplets of water will evaporate even slower.

If you experience residual knock, you may just add more flow to compensate for the losses into big drops. As long as your ignition copes, you can just add more.

[Flr Power]

rotrex, what is your definition of residual knock?

[blue]

Some good info here
I get your main point that the goldilocks option is the worst one in this scenario
But with many of us running high percentage of water mixes will the extra distance really help that much
Or is it just more surface area to stick or puddle on Especially if it has to pass an intercooler of some sort?

[rotrex]

Originally Posted by Flr Power

rotrex, what is your definition of residual knock?

I mean with this that you cannot get to Maximum Brake Torque (MBT) through timing or at least getting close. In other words, if you are still significantly knock limited.
"Residual" was probably not the right word to use in this context I admit.

regarding injection further upstream, one has to take into consideration that smaller droplets more easily pass bends and intercoolers.
Also in high boost applications, the turbocharger's output is very hot and can evaporate a fair amount of fluid.
This no black and white. These are just factors why some need more or some need less mix or different ratios to get to the same results.