Hitchhikkr

Uhh. Are you suggesting that water "boils" in your intake? You do realize that in order for water to boil in your intake tract, gas or diesel, your intake charge would have to be WELL over the 14.7ambient boiling point which is 100C depending on your altitude. Not to mention the fact that pressurized chambers defer the boiling point of water.
It may take less water to absorb the same amount of heat energy, but time is your problem. We're talking about NANO seconds that air molecules travel through your intake on a forced induction engine. The air doesnt have TIME to absorb any heat in its presurized state.
Did you not read the whole post? There is no change in airmass with water injection. Therefore there is no change in temperature in the intake.

As I recall you were asking some pretty noob questions a month or so back, now you know more than JD and everybody else that has had experience with this
Enlighten me with your uncontrollable knowledgablilities.

Tom-Guy

Which has nothing to do with anything, as no one I know of injects a cetane-rated hydrocarbon into their SI engine.

Which also has nothing to do with anything.

I started with a NACA report condensing a handful of other full-length research papers conducted by engineering and physics PhD's that states there is no cooling of the intake charge from water injection, and from this you throw a NACA report about ----------ing diesel evaporating in the intake tract in my face to refute me?

You lack any and all basic clues, including but not limited to:

- high school level physics
- real-world experience with how cars work
- basic logic
- basic common sense

Please, feel free to insert both of your fists into your rectum.

fe3tcourier

as much as i don't really want to argue with you (just to let you **** off mr arogant : JD) i do have to in this instance.

when diesel enters the chamber, it does so at VERY high pressure, further more, when diesel enters the chamber, the air is above the flash point of diesel ie 400C, because of this, the instant that ANY diesel evaporates, it starts to burn, and it is this heat that provides energy for the remaining vapourisation to occur. the temperature of the surrounding air is not lowered significantly by the diesel because of its low latent heat capacity. i would hazard a guess that the initial ignition of diesel is aided by additives that evaporate more readily and start the process.

i wish JD had not used such poor england in the first place. i mean, what he should have said was "no significant charge cooling will occur from a hmt water cooling setup on a well thought out engine system because of the short distances and low temperatures involved" rather than "water does not cool the intake charge at all"

as for hitchy regurgitating that "engineering" stuff... they did not use suitable apparatus to find a power gain from the cooling effect. thus the fact that they found no gain is not surprising. the fact that they were injecting it very close to the ports might have something to do with that...

as for the cold intake = good or bad thing... the only time it could be either is when the system goes from cruising with water off to boosting with water on. at that point, some energy may be carried though the engine with the water, but its not going to effect power either way significantly because A there wouldnt be enough of it per cycle to matter and B the energy is in the change of state that the water has gone through when cooling the manifold. the reason it cant be good is the low surface area of air in contact with it... thinking that is along the same lines as those manifold insulators... ie, a waste of time.

assuming that you didnt adjust any operating parameters like ign adv, any power you felt you felt because of the angle of peak pressure moving to a more optimal location because of the cooling and lack of preignition etc.

i still argue that on a fundamentally bad setup with long large pipes and very fine mist injected right after the inneficient off the map turbo, a charge cooling effect will be found. however on a car with a properly sized turbo and a reasonable amount of boost and normal sized pipes, its just not going to happen.

as for air speed :

i did some caclulations just now, and we are talking about roughly 0.4seconds between water injection if done at the turbo and charge consumption at the engine. that would be 400 milli seconds, and 400 million nano seconds. thats right, 400,000,000 nano seconds. on my engine that is, with all components sized for 500hp+. not including the intercooler of course. could get it down to around 0.25 of a second with non intercooled plumbing routing... but still...

get your figures straight hitchy ;-)

b18.

You can use water to prevent detonation by technically raising the octane of the fuel, octane determines how explosive petroleum based fuel is, or rather how fast it reacts with gaseous elements (air, O2 explicitly), and "fast" being amounts in our case. Specifically what amount of a catalyst, heat in this case, is required to instigate a combustion reaction. If you have more oxygen it is harder to ignite the mixture because the molecule has a strong bond between eachother, and there is less readily available carbon or other element for it to burn and bond with. More heat will result in a faster reaction but a denser charge makes it harder to ignite the mixture completely, hence you'd rather light the mix with a spark plug than by dieseling, or detonating rather (compression causing enough heat to ignite). The reason you would make more power with water injection is the ability to turn up the boost, (more gas denser charge) because you have raised the threshold for detonation by making the charge harder to light.

Please JD edit that, I am very stoned.

omgbossis21

If you tune for it you can see some great gains! My turbo is past its eff. range so im sure thats why it feels so much better now. As for not cooling anything.... It cools the combustion which in turbo would lower egts which would lower turbo temp which would help to lower the temp of the air at the turbo outlet no?

USS

PV=nRT owns you.

fe3tcourier

lmao, and to the poster above that, the answer is no.

by two very dated empirical tests.

omgbossis21

Heres a good thread about water injection I found :
http://www.eng-tips.com/viewthread.cfm?qid=72284

I was just shooting in the dark with that response since i dont care to argue all this scientific crap Hell I cant even argue the thermo dynamics of how the turbo works, I just know it works. I know the injection system is working for me, thats all i need to know to go with it.

b18.

The resistance to pre-ignition is determined by the molecular structure, in the case of aliphatic hydrocarbons the maximum number of oxygen molecules that can bond to any hexagonal chain is four, making an octane molecule. To increase the octane of gasoline things like benzene or toluene are added, water does the same thing, it has a molecular bond with Oxygen that is strong and polar, i.e. it takes more heat to break the bond and instigate combustion. I'm quasi-sure that having a fuel with a stronger molecular bond necessitates more energy to break, so that's why water injection helps. [

quote author=Snafubmx234 link=topic=83240.msg1020989#msg1020989 date=1190930697]
PV=nRT owns you.
[/quote]

This went through that guys head:
"ROFLLOLZ OH NOEZ U MISPELD PERVERT ROFLCHOPTHER!!!!!!11!1"