Symptoms of too much Water Injection

TurboGTi · #1 27-10-2004, 02:55 PM

I'm just wondering what are the symptoms of too much water injection.

Also what are the limits of water injection, can too much be injected?

suppose i increase timing on my engine and the boost to an absurd level and run two 1.0mm jets ... What are the consequences?

I know it is a strange question but what i really want to know is what is the most intense water injection Set up that you have or have come accross?

SaabTuner · #2 27-10-2004, 05:40 PM

NACA ran a WI with just water rate of 1/2 lb for every lb of fuel all the way to 10:1 A/F ratios or so. That's a pretty good amount of water.

Most modern cars have ignition systems designed with the exact voltage required to ignite the mixture in mind. So if you make it too hard to ignite the ECU has trouble. Also the NACA engine was 7:1 compression, higher compression engines will be even harder to ignite. Theoretically I'm not sure what the limit is. Diesels often run more water than fuel.

I guess the limit is wherever you end up when you can't get any more power by adding more, no matter how you tune/upgrade, and I'm not sure that point has been reached.

Adrian~

TurboGTi · #3 27-10-2004, 10:07 PM

hmmm good point adrain.

Well the reason i was asking is that i would want to run a twin jet setup with more boost .... but the catch is i would want one jet to run at 8 psi and the other jet to start at say 15 psi ......
... i belive that the only way to do this is to use a 2D system from aquamist, with the HSV used as the secondary jet ...

.. Do you think this is possible. :?:

Slump · #4 30-10-2004, 06:33 PM

This is a dyno of my car.

The blue line is "too much water", and the red line is a more correct amount of water.

The only difference between the two dyno runs is the adjustment of the quantity of water injected using the Aquamist MF2 controller (part of the System 2S).

Gelf · #5 30-10-2004, 07:59 PM

Quote:

Originally Posted by Slump

This is a dyno of my car.

The blue line is "too much water", and the red line is a more correct amount of water.

The only difference between the two dyno runs is the adjustment of the quantity of water injected using the Aquamist MF2 controller (part of the System 2S).

Do you mean you changed jets or reduced the amount with the same jet ?

If you changed jets, which size did your change from and too ?

TurboGTi · #6 30-10-2004, 08:41 PM

Hmm nice post Slump, it s almost like your engine was drowning in water,
That a big jump in power bny just proper tuning.

I don't like how the power curve gets a bit jagged at the higer RPMs like from 5500 RPM onwards ..

Are you running a high timing advance on your engine? or maybe too little water injection at that point... Also are you injecting pure water or are you mixing ......

I noticed a big difference when i used a 0.9mm jet versus the .5mm jet on my set up. The engine wouldn't bog as much and it didn't feel strong enuff.

I'll be dynoing sometime this month so i'll be checking my water injection system to see my gains ..

PuntoRex · #7 31-10-2004, 02:33 AM

Dyno is surely good, but too much water can be easily felt.

I'd used 1S system for a couple of years, in some cold winter days, the "summer jet" could be felt obiously. Engine output was clearly softened & faded. Swapped to a smaller jet immediately livened it up.

The other example is once the manifold pressure switch failed, the water was continuously injected (in a rush hour traffic jam) until I could find a place to pull over & unplugged the fuse. I barely managed to do that because when low rpm/off boost/idle, full flow of 0.7mm jet really made the engine stumble. I could only kangarooed along weakly. By this, the water for a whole week was injected within several minutes.

Fortunately there's no permanent damage.

Richard L · #8 31-10-2004, 09:18 AM

Quote:

Originally Posted by PuntoRex

Dyno is surely good, but too much water can be easily felt.

I'd used 1S system for a couple of years, in some cold winter days, the "summer jet" could be felt obiously. Engine output was clearly softened & faded. Swapped to a smaller jet immediately livened it up.

The other example is once the manifold pressure switch failed, the water was continuously injected (in a rush hour traffic jam) until I could find a place to pull over & unplugged the fuse. I barely managed to do that because when low rpm/off boost/idle, full flow of 0.7mm jet really made the engine stumble. I could only kangarooed along weakly. By this, the water for a whole week was injected within several minutes.

Fortunately there's no permanent damage.

Interestingly, we have a few nervious users putting two pressure switches in parallel (806-157) electrically. Being normaly closed switching configuration, both of the switch has to be open-circuited in order for the WI to activate.

PuntoRex · #9 31-10-2004, 09:48 AM

That seems overkill.

Anyway, now I'm running on 2D, so the pressure SW failure would not be so dramatic. :smile:

Richard L · #10 31-10-2004, 10:40 AM

Quote:

Originally Posted by TurboGTi

Hmm nice post Slump, it s almost like your engine was drowning in water,
That a big jump in power bny just proper tuning.

I don't like how the power curve gets a bit jagged at the higer RPMs like from 5500 RPM onwards ..

Are you running a high timing advance on your engine? or maybe too little water injection at that point... Also are you injecting pure water or are you mixing ......

I noticed a big difference when i used a 0.9mm jet versus the .5mm jet on my set up. The engine wouldn't bog as much and it didn't feel strong enuff.

I'll be dynoing sometime this month so i'll be checking my water injection system to see my gains ..

I think the limiting factor of "over water" is governed by the ignition system. On diesel engine, I have injected 600% !!! of water top fuel and the engine carrieds on running, not very nicely though - it was like a steam engine watching the exhaust puffing out white smoke (steam)