WONDERING IF: civic vx turbo 6 psi water injection NO TUNE

[rountreesj]

wondering if this would be possible:

d15z1 honda vx engine
has leanburn when not under load 3 valves per cylinder under 2500rpms
if i turboed it with 3-6psi and made a water injection system to keep the cylinders cool and kept the ecu untuned.

would:

the 5 wire o2 sensor read the water coming out in the exhaust as more o2 and thus add more gas?

the water not prevent detonation from running too lean (this assuming the o2 would not compensate with added fuel)

the water cause the piston walls to be "washed" and therefore cause unwanted wear?



I ask this, because it seems as though the water would NOt cause more combustion, like the Brown's gas is rumored to - it is o2 gas or something, but rather, the water would cool the engine when running lean.

typically with a turbo car, the extra fuel is NOT added to keep the air fuel ratio at a certain point to keep combustion happening, as i used to think, but rather simply used to keep the engine cool, the same way that spraying water in would. liquid gas has the same thermodynamic cooling effect as water would.

the main issues with this thought are, the possible wear in the engine from too much water, the cost of a system that would mist the water fine enough for this to work, and the actual ability to do it with this engine and its physical setup.

another thought is if this would even be necessary as the engine is designed to run lean not under load and the ecu does indeed give more fuel at high load, so tuboing only under high load could have the engine essentially in lean burn always...


your thoughts ecomodders...

[niky]

Water injection should help prevent detonation under load, but you will have to size your nozzle properly and would have to set it to come on only under load, otherwise you would see it washing down oil from the cylinder walls.

And then there's the problem of, when you've tuned the water injection perfectly to prevent detonation and engine damage, engine damage occuring anyway when you run out of water.

[rountreesj]

well there could be ways around this even. there are elecric cutouts, basically a big solenoid that you could put in the tubo piping, or even could install manual choke setups to open a n/a loop. could also find a cheap float valve low water indicator and just add water when it is done.

also was reading that most mix an oil with the water etc to prevent washing of the walls.

its not REALLY practical, but if planned right, a junkyard turbo setup could be made. no intercooler would be needed, jut the manifold, turbo, piping, and water injection system.

my younger brother suggested a small carburetor system to pump in water.

my idea was to use boost pressure to basically suck in water just like a straw. put a check valve in and use a needle valve to manually adjust to tune, and some form of atomizer to mist the water.

i read somewhere even people sprayed pretubo, and the turbo breaks up the water into a mist. if there was a way to control flow with the boost causing a suction of sorts that would open a valve for water to spray in pre turbo, then it could work REALLY well for a low boost, no tune setup. with this reasoning, you wouldn't need to tap the oil pan and feed the turbo with oil either since the water would cool it. its pretty ingenious IF it could WORK. IF I CAN GET IT TO WORK LOLOL

[oil pan 4]

Water injection - EcoModder

Problem is no one seems to have been able to find a good way to boost fuel economy on gassers with water injection.
But when it comes to boosting performance, yes it works.

Running out of water or water methanol can be a big problem if you are set up to where you need it.

[rountreesj]

i have been researching and it has been done, but usually for performance.

and a manual boost controller could really make emergency water shortages not a problem

on a large car, or a track car this would not be very feasible, but on a car that uses LITTLE gas already, the water would not be used in 5 minutes and might last for a week or so depending on driving...

through thought and research, my design would be:
-manual boost controller as a fail-safe if no water present, jut turn down boost
-external 2 gallon tank
-adjustable pressure activated switch
-solenoid wired to pressure switch normally closed, opened when pressure in charge pipe
-nozzle for atomization
-needle valve for calibration

i assume one could basically introduce the boosted psi to the external water reservoir causing the pressure in the tank and lines to the nozzle to increase, then a boost pressure switch inline activating the solenoid to open releasing water. one would want the solenoid to open slightly before the air would reach detonation levels and close normally, preventing the water from leaking into the engine. a pressure purge on the system would greatly help with this. many use washer fluid because it wont freeze, but in summer, regular distilled water should be fine, and my thoughts are that normal water would PROBABLY be fine too...

this way one could induce a lean burn situation and REALLLY shoot for super lean mixtures or advanced timing and get the benefit of turbo power, less gas use, and water as fuel. plus the water steam cleans the engine and would make it last longer.

just like in a turbo that sucks at gas mileage but produces power reliably, its all in the tune. this system would have to be tuneable, but is it possible to tune just the water and boost and not the ecu? maybe.....

[oil pan 4]

Originally Posted by rountreesj

i assume one could basically introduce the boosted psi to the external water reservoir causing the pressure in the tank and lines to the nozzle to increase, then a boost pressure switch inline activating the solenoid to open releasing water...

All ready considered it and ruled it too much of a pita
Here is what I built to resolve the situation:
DIY Water Mist Injection system install, w/pics (MPG Boost Project) - Page 26 - Diesel Place : Chevrolet and GMC Diesel Truck Forums

Instead of lean burn had you considered bumping the compression and running a more normal A/F ratio?

Lean burning a turbo gas engine is a sliperly slope.

[rountreesj]

well the purpose was to get the engine to produce the same power, not more, with a turbo on low boost, and keeping the fuel input the same.

i dont want to build the internals of the engine, so i am not trying to make more power, but simply the same power with less gas.

by running the boosted engine lean, the car would essentially make more power with the same amount of gas, but to prevent problems i was going to spray water in to keep detonation from happening.

for larger engines, i can't see this thought working well, but for a smaller engine that gets 50mpg normally, introducing slight boost causing a lean situation would allow the car to run lean even when under load, and the water would keep it from getting too hot, then i could see the 55 mpg even when accelerating harder or moving faster.