Water injection (was: Re: fuel cooling intake air)

Bruce Plecan nacelp at bright.net
Mon Jul 10 03:52:22 GMT 2000



> > > However, I still stand firmly behind what I said: if you let the water
> > > evaporate before it enters the engine, you displace oxygen, and no
> matter
> > > how little, this is a bad thing.

> > What is water made of?.

> ..water, an inert substance, as long a internal combustion engines are
> concerned. And that water is expelled at the exhaust as.. water, too, or
H2O
> if you prefer. All of it.

Oh, so at not time it can change?.
Well water does respnd to electrolyse, what is the ignition spark?.  So
while how ever small, some most likely does seperate (into it's compnents H
and O), it will / may go thur several other reactions, but yes the total out
the pipe will equal the sum of it's inputs.

> > >Also, water do nothing more than prevent
> > > detonation, just turning on the water jets does strictly nothing to
your
> > > torque output.
> > Haven't seen anyone claiming that. (unless the motor already is
> detonating,
> > then there will be gains) (diesel applications, again rears it ugly
head,
> > and your not addressing those).
> It's easy to observe, especially on a dyno. In my own experience, just

> turning on the jets didn't change the torque output at all. I believe no
one
> will claim to have gained anything by just injecting water without making
> any other change.

Did you read my last comment?.

> >  You can however use more spark advance if required, or more
> > > boost, and from that comes the gain.
> > Fuel is not an element in this, hmm, odd to my way of thinking

> Well, more boost means more fuel, hopefully.

But you excluded it in your first statement.

 Your ECU is supposed to take
> care of that since an encrease of boost will show up at the AFM or MAP
> sensor, and water has nothing to do with it, unless, injected 'early',
that
> water has evaporated and cooled down the charge (I don't deny the cooling
> effect, I say the benefits of a lower temp, density wise, is lost because
of
> dilution).

The ECU will see a lower air temp and add more fuel,

So all ecu / ecm do this?, hmm wrong.

 which in
> this case would be a mistake since there is no corresponding increase in
> oxygen (your turbo is not going to swallow any more air because you inject
> some water after it, right?)

No

> However, in both types of engines, there is a lot to be gained if a normal
> combustion can be maintained with more boost or compression ratio.

If the timing and fuel are correctly adjusted.  (Timing as used here is for
ignition (SI)or fuel injection timing on a diesel)

As soon
> as you get end gases detonation or, worse, runaway detonation (also
referred
> to as preignition) the game is over.

Runaway?, how about uncontrolled?.  Since a diesel engine uses a form or
controlled detonation.

> >  If cool air is what you want, you must
> > > increase the efficiency of the intercooler, spraying water on it being
a
> > > popular option.
> > AGAIN, THIS IS ILLEGAL in some forms of racing.  They (the rulers makes)
> in
> > some forms of racing consider it dangerous to spread liquids on the
> > track!!!.   I just as a matter of common sense don't want to be racing
on
> > asphalt, will some one spraying water on the track.
> Why "again"? I don't recall you said it before (sorry if I missed it).
Also,
> you suggested cooling the IC with NOS, a substance definitely not allowed
in
> FIA rallying, water however, is allowed there.

They let them drop water on the street, yet gaseous cooling is illegal?.
Some set of rules, IMHO.

> > BTW, how do you keep any water from evaporating in your system?.  I mean
> if
> > it's such a bad thing, in your opinion.  Would mean that, the whole
system
> > would have to be at jus over 32dF, or is there some error in your
> statement
> > "you displace oxygen, and" yada yada, or is a gross over statement of
> > fact...

> It is reasonable to think that if you inject close to the valve, less
water
> will evaporate outside of the engine, thus less oxygen will be displaced.
In
> contrast, injecting before the IC obviously gives much more time for the
> water to turn to vapor and thus displace more oxygen.

But, you said **any** Oxygen displacement was bad.
Grumpy

> Axel


----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org




More information about the Diy_efi mailing list