[s-cars] Water Injection

[Kirby Smith]

Let's not confuse water injection and water cooling.  Water injection
cools the intake air directly by extracting the heat of evaporation.
Water cooling cools the intake air indirectly by reducing the
temperature of the intercooler.

Where to water inject is a not-so-easily-answered question.  Up steam of
the intercooler would ensure no liquid made it to the engine, and would
be where the air charge temperature was the highest, thus evaporation
the best.  On the other hand, injection upstream when the intercooler is
still cold would lead to condensation in the intercooler.  This could be
avoided by having a control system that was based on the intercooler
output temperature.  Downstream of the intercooler might lead to cleaner
valves, as the generation of steam from water mist at the valves is
reported to clean them.  Best results in either case should result from
use of good atomization nozzles, which implies high pressure water.

kirby

Bruce wrote:
>
> One big question I have is where should I inject the water? Outside of the
> intercooler seems safest, but most people seem to do it just after the
> turbocharger. Any suggestions?
>
> Bruce
> ----- Original Message -----
> From: "mlp" <mlped at qwest.net>
> To: "Bruce" <brucem105 at comcast.net>; <s-car-list at audifans.com>
> Sent: Saturday, July 06, 2002 9:29 AM
> Subject: RE: [s-cars] Water Injection
>
> > Ah ha, there.  Finally found it again.  A slightly better description of
> the
> > old Old's system,
> >
> > http://www.tctc.com/~posumrun/mph/pageCLIP/page62JET/62jet.htm
> >
> > "....This was solved by adding a fluid injection system. A tank of
> > "Turbo-Rocket Fluid" (a 50-50 mix of water and alcohol with some rust
> > inhibitor added) was mounted under the hood. When the turbocharger
> operated,
> > it also pressurized this tank and caused a small amount of the fluid to be
> > injected into the intake between the carburetor and the turbocharger. The
> > fluid evaporated, absorbing heat from the intake air and preventing
> > detonation.
> >
> > Oldsmobile was famous for conservative engineering, and the Jetfire
> > turbocharger installation was no exception. A warning light informed the
> > driver when the Turbo-Rocket fluid ran low. If it was allowed to run out,
> a
> > butterfly valve in the throttle body closed to prevent full-power
> > acceleration. The wastegate was operated by two diaphragms in case one
> > failed. Even if that happened, the cap on the Turbo-Rocket fluid tank
> would
> > pop off to prevent overboost. And if boost pressure was still too high,
> the
> > butterfly valve would again shut down the party. One Olds engineer told
> Car
> > and Driver, "It's 'safetied' to death."
> >
> > There you go Bruce, ".... a mixture of water, methyl alcohol & a rust
> > inhibitor...."
> > and Oldsmobile's famous conservative engineering.   What more can you want
> > in the way of proven engine safety.  Even the rust inhibitor shouldn't be
> > any kind of a problem
> > with all the aluminum parts in the Audi's engine.  :-)
> >
> > mlp
> >
> > ~-----Original Message-----
> > ~From: s-car-On Behalf Of Bruce
> >
> > ~As usual, I have read so much that I am more confused than when I
> > ~started. (Rod, thank you for the great advice and URLs!!).
> > ~
> > ~In the bang for the buck performance category, and especially
> > ~since my car sees a lot of track time, water or water/alcohol
> > ~injection seems like a pretty good idea. I am going to try it.
> > ~
> > ~
> >
> >
>
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