basic water injection non boosted

[Tasmaniak]

anyways... back to me!

So this was the inlet side if my heads about a week ago. In two weeks time, I will removing the manifold again to remove the injectors to get them cleaned. I'm estimating in that time I will have driven approx 2500km with water injection. I'll be interested to see if by that time there will be any noticeable results. I'm expecting nothing after a few short weeks, but nonetheless I'll grab a comparison photo anyway.

 

[Tasmaniak]

oh also, someone asked if I could perhaps post a photo of the vac port I used...

Here is my motor, on the throttle body you can see two blanked vac ports just in front of the throttle plate. I went in there. Plenty of vac and no sensors.

 

[Bowen]

So took me a bit to catch up bit of reading but that link delco posted is quite an Awsome cheap system by cheap I mean like $10 worth, but no one answered the important question which was would the extra air which is being sucked in after the MAF effect the afr's and the confuse the PCM? Also I don't see why you can't use the purge line under the throttle body like immortality was saying

 

[TheVsStig]

there were alot of questions that never got answered by some people passing them off as unnecessary but alwell. none the less there has been some awesome input on this, you know who you are and i thank you. i've been to jaycar and bought a few things, i've just gotta order a pump from ebay and we're in business. i've come up with a setup the uses one of the injector signals to pulse a water injector. it will run of a fuel pump thats connected to a pressure cut off. also a switch on the TB that cuts powere to the injector when less than 5% throttle is applied. i know this grows abit beyond a basic water injection setup but the whole vacuum thing wouldn't work on my car. since i have a injector laying around this whole setup will be less than $50, and through control of line pressure and an injector pulsing in sync with another, will keep a constant 10% fuel to water/meth ratio.

 

[Bowen]

there were alot of questions that never got answered by some people passing them off as unnecessary but alwell. none the less there has been some awesome input on this, you know who you are and i thank you. i've been to jaycar and bought a few things, i've just gotta order a pump from ebay and we're in business. i've come up with a setup the uses one of the injector signals to pulse a water injector. it will run of a fuel pump thats connected to a pressure cut off. also a switch on the TB that cuts powere to the injector when less than 5% throttle is applied. i know this grows abit beyond a basic water injection setup but the whole vacuum thing wouldn't work on my car. since i have a injector laying around this whole setup will be less than $50, and through control of line pressure and an injector pulsing in sync with another, will keep a constant 10% fuel to water/meth ratio.

So this pump will the pressure be regulated at 3.5 bar same as the fuel pressure for these injectors? Where abouts is the point your mounting the injector? With that finer mist of water I don't think you'll have to worry so much about cylinder distribution if you inject pre plenum.... It's almost just like humidity lol wouldn't be much weight to it.....

Make sure you post up a heap of photos, also where will the resivour be located? Boot mount for super stealth? Also I know you mentioned about resistors etc but how are you going to get around altering the resistance / voltage etc at the petrol injectors?

 

[TheVsStig]

hi Bowen. if i left the water injector at 45psi wich is fuel line pressure, it would be 1/7th of the fuel to water ratio. we need it to be 1/10. so i will either be buying a pump with a suitable adjustable pressure in the range of 10-30psi or a pressure regulator. i assuming i line pressure of about 20psi instead of 45 psi would reduce the ration from 14.4% down to about 10% (THIS IS JUST A GUESS TESTING NEEDS TO BE DONE).

the injector is located at the start of the 90 degree bend leading to the T/B, and the injector is facing directly toward the T/B. the average injector has a resistance of 11.8 to 13 ohms, by wiring the second injector in parallel with injector number 1 the resistance of the circuit drops to 6 ohms. to resolve this a 5.6ohm 5w resistor is placed on the wiring leading toward injector 1. this resistor has to be closer to the ecu than the parallel wires running to the water injector, otherwise the resistance will be something like 8.5ohms. the negative wire runs to a switch located on the T/B to cut the circuit at less than 5% throttle. the wire then travels to a cabin master on/off and back to the negative terminal of the water injector.

a suitable pump (probably a fuel pump) and tank are placed in the boot (10L is my goal). the power for this is boosted from my subwoofer wiring. this pump also has a master on of switch in the cabin.

so far i'm a bit over halfway. i just need to buy a pump and a pressure regulator, if i cant find a suitable pump. find a suitable tank to place in the boot, with a hose running to the engine bay (im not sure if i will be running this hose through the cab or under car).

when i'm done i will make a proper detailed write-up, with photos and a wiring diagram. in total it will cost me $30-$60, but i already had a injector.

EDIT - notice up the top i said 1/7th not 1:7 the ratio would be 1:6 if it is 1/7th. also i didnt use a purge line as i had trouble with vacuum, and i want a better system than just vacuum. this way once i set the right line pressure i can maintain 10% water to fuel ratio right the way through my rev range no matter how much accelerator i'm using. i can turn the system on when the car is warm, and off a k or so before home to ensure there is no water left. i can also mount the tank in the boot out of the engine bay.

 

[ari666]

so youre putting two 12 ohm injectors and a 5.6ohm resistor on injector circuit #1?

 

[TheVsStig]

yes ari when you put 2 12ohm injectors in PARALLEL it reduces the resistance to 6ohms. by putting a 5.6ohm resistor on the wire leading to injector 1, but closer to the PCM than any injector it restores the circuit resistance to roughly 12ohms. 12.8 in my case but my injectors resistance has increased with age.

EDIT - if your putting your multimeter on the circuit and reading something like 30ohms. your doing it wrong, your reading series resistance not parallel resistance. btw i've had the car running and it runs fine with no error codes. flicking the water injector switch on and off makes no difference to idle or anything like that, even though i have noticed a flaw in my wiring.

with where the resistor is placed when the water injector is turned off the circuit resistance will might jump to 17ohms. so far this seems to have no effect on the car but i will remedy this by using 2 5.6ohm resistors on the wires leading towards the water injector (i think thats right). if you just use one on one wire leading to the w injector it will only add 2.8ohms of resistance (i think). someone with more electrical knowledge could help here, if not i'll just do some testing.

 

[ephect]

you cant just look at the ohms to make it work. by adding a 5.6ohm resistor in series to the 2 parallel injectors your screwing with the amount of current that needs to be fed into the circuit. So 1 injector will be fed more Amps than the other 5, putting more load on that 1 feed.

for resistors in series, the current is the same for each resistor = voltage varies
for resistors in parallel, the voltage is the same for each one = current varies

 

[TheVsStig]

so what your saying is atm my current varies but the voltage stays the same? i'm not too worried as long as the voltage stays constant as it seems to be running fine.