water/methanol cooling question

[jetmech]

Just want to double check here. Running pure water injection will cool everything down and have no effect on AFR, right? Similarly, pure meth will cool everthing down and richen up the AFR, right? But which will cool everything down better, pure water or pure meth?

[st8kfinger]

im no where near being an expert on meth injection, but i dont see any reason to just run just water, idk but any time you put anything into your motor its gonna change the afr?? i think most windshield washer fluid is 51% water and 49% meth, so that is a good happy medium. worst case is if your afr is too rich with the meth you could turn it down or run more boost. like i said im not an expert but you could have your truck tuned for meth and washer fluid is $1.50 or less/ gallon. do you have an inner cooler?

[Chavy]

Not an expert either....but have gathered that both have greater heat latency than gasoline. Water has methanol beat by 3 to 1 in that ranking, so water is the better cooler. But water doesn't combust or provide fuel enrichment, so Methanol is the clear winner as Octane booster. Outside the purists.....I believe many adjust mix, change jet logistics, change pressure, etc. to try to find an optimum mix to get the engine to gobble as much water as possible without stumbling...best of both worlds. The mix arguments are all over the place...though statistically close to 50/50 mix seems to be the average....but then there is also the argument as to whether the mix is Volume or Weight....which are clearly different. I'm playing with a 50/50 by volume for now, trying for the best of both worlds and arguably a little safer than spraying 150 to 250 psi straight meth in a hot engine compartment. IMO for the time and trouble there are other better ways to add a few ponies, but hey its really for the entertainment value anyway, right.

[jetmech]

If water is the better cooler then that's what I'll stick with. I started running rich after the boost controller went on so I don't need the AFR enrichment that the meth provides. Yes, I run an intercooler BTW. I'm trying to dial in my boost controller just right and at the same time, obtain the optimum water/meth mixture for the desired 13psi (hi boost). The AFR is looking better on 100% water tho - about 11.1 @ 12psi. I'm trying to stay out of the 10 range on the wideband. God help me if I get close to 12 tho

[Chavy]

Methanol stoich is 6.4 vs. gasoline at 14.7....so 11.1 on gasoline equals going rich whereas depending on how much meth is going in vs. gasoline....hard to say where the 11.1 lies (but probably not as bad as you are thinking). Bottom line you are adding for performance so whatever yields you that. I tune without the meth/water to pe of 11.5, then increase spark in adder table for cooler temps. I don't worry with the resulting AFR during injection unless it goes lean since I don't have a precise way to know what my new mixture is. Of course there maybe some experts herein that have some good ideas on that or other so I am all eyes. cheers

[1fastchevy]

Oh shit my head hurts now.


G/L

[jetmech]

Methanol stoich is 6.4 vs. gasoline at 14.7....so 11.1 on gasoline equals going rich whereas depending on how much meth is going in vs. gasoline....hard to say where the 11.1 lies (but probably not as bad as you are thinking). Bottom line you are adding for performance so whatever yields you that. I tune without the meth/water to pe of 11.5, then increase spark in adder table for cooler temps. I don't worry with the resulting AFR during injection unless it goes lean since I don't have a precise way to know what my new mixture is. Of course there maybe some experts herein that have some good ideas on that or other so I am all eyes. cheers

Interesting. I'm still using the MAF's IAT sensor so my ecm isn't picking up the drop in temp from the water/meth. I know it would help to relocate the IAT after the meth nozzle but right now I'm only concerned with my AFR at 12ish pounds of boost. I understand what you are saying about the tuning and I agree. I did the same thing. I tuned without the meth, then switched it on. Although the stoich AFR for meth and gasoline are different, the wideband still gives you a pretty good idea of where the AFR is. To be honest tho, I'm just looking for cooling so for now, pure water will do the trick. Thanks for the input dude

[SCIV]

Doesn't the water vaporize? What happens to the oxygen molecule? So even water adds more oxygen, so it could lean the mixture?

[Chavy]

I believe in vaporization the strength of the Hydrogen bonds stablizes the molecular equation and maintains the two hydrogen to one oxygen atom ratio. And if for some reason the one oxygen atom was released there would be two hydrogen atoms now available for combustion, hydrogen being highly combustible and having high thermal conductive properties (and a mute point since it don't happen like that). In reality, the water vapor ends up going out your tailpipe and becoming condensate along the way as it does. IMO the engine stumbles on too much water due to other reasons (like drowning in water and not enough oxygen). The biggest risk I know of to lean in meth injection is if someone tuned an enrichment table for meth and then their meth failed.

[jetmech]

Well so far, I'm running really strong on pure water. I understand the chemistry of the situation but, again, I'm just looking for cooling. Besides, water/meth systems use high pressure and a nozzle with a very small orifice in order to spray a fine mist which helps vaporize the liquid quickly.