we should all inject water

[WILD VR CLUBBY]

hey guys just a thread on water injection. feel free to ask any questions or input anything you wish to, there is no wrong or right so keep it friendly.

so here's the story, ive just done a l36 to l67 top swap, shes running 10psi pulley, 1.9 rockers, ported heads with polished domes, 80deg thermo, huge 52ml alloy radiator, and a real time tuning nvram so I can log and tune via tuner pro.
so ive had her running for a day now and I can tell you right now. without any tuning or some sort of knock suppressant this motor would not last long. I did a casual 15 min cruise down shifting through corners and giving 60ish% throttle and I logged a lot of knock on 98 bp retarding anything up to 14deg timing.

so I sat down and looked over my logs and decided to start pulling spark all over the table, then bam the idea hit me. why not water inject. off to Bunnings I went brought some 90ml pvc pipe, got myself a window washer pump, an old injector which I had left over from the l36 top and made my own water injection kit. cost roughly $5 a lil more if your not a hoarder like me lol.
if you want a how to guide or any tips let me know

so im yet to do a proper run with her yet but from the log I just did stationary and reving, ive pulled that knock right back to max knock retard of 2deg, and that's without tunning anything.

so love it or hate it but so far I love it!

 

[Immortality]

I'm not surprised.

L67 = 8.5:1 CR

L36/ecotec = 9.4:1 CR

10psi on a stock L67 is pushing the boundaries of the factory tune. Doing so on a ecotec bottom end is asking for trouble. Take into account that the ecotec has much weaker pistons than the L67 and won't take much abuse before you loose a piston crown.

Out of curiosity, where are you injecting the water into the engine?

There is also another active thread running on this subject although based on a non-boosted engine but may have similar info as they are using a fuel injector with home made driver to run things.

 

[ari666]

we have gone into great depth already here:
http://forums.justcommodores.com.au...239827-basic-water-injection-non-boosted.html

but feel free to throw up the way you went about it. this ^^ "basic" water injection, soon got pretty complicated. but yeah dont think he spent more than 60 odd bucks.

 

[lowandslow]

Higher comp + more boost with no intercooling means you were going to see knock from the get go.

 

[WILD VR CLUBBY]

Ari I'm running a normal window sprayer setup separate to the original its setup so the pump runs constantly with a hose with a T in it. One to the injector the other back into the bottle. So it recirculates when the injector is off. The injector was installed into a PVC pipe pre charger. To get a snug fit I drilled a small hole then used a lighter to heat, then pushed the injector through. I'm making your circuit to pulse the injector but what I can't work out is which side of the injector the start of the circuit comes from you referred to it as the low side. I also can't work out where the other wires join to the other injector. It says vcc which I assume is constant voltage but it then also says to run it to the other injectors plus wire???

 

[ari666]

the injector is just a coil, so there isnt really a + and - side. any way will do. as long as you have +ign and -ecu pulse.

VCC in my diagram is ignition "on" you dont want it constant or itll be charged while the car is off. i personally would run the circuit and the additional injector off the + circuit your other injectors use.

 

[07GTS]

some injectors are polarity sensitive and some doesn't matter, my Bosch one's can go either way and the ones i replaced do have a + and - symbol inside the plug at the base of the connector pins...

 

[WILD VR CLUBBY]

ari are you saying to connect the low side of the circuit to the - side of the injector and the vcc to the + side of the injector?

 

[TheVsStig]

we have gone into great depth already here:
http://forums.justcommodores.com.au...239827-basic-water-injection-non-boosted.html

but feel free to throw up the way you went about it. this ^^ "basic" water injection, soon got pretty complicated. but yeah dont think he spent more than 60 odd bucks.

lol yeh it really left the basic part behind, little computer boards with transistors, resistors diodes and the like lol been very educational though. sorry to hi jack thread OP.

btw post 221 and 237 on my thread should help with wiring but basicaly the system gets power from vcc and a signal from the negative side of a fuel injector. you then connect a positive and negative to the water injector and a negative to the battery (i think double check that though). please don't take resistor and transitor values and codes from the diagram though, THEY ARE WRONG AND YOU LOSE MAGIC SMOKE. i think it's post 117 that ari put up has a full parts list, the list is correct as they are 548 not 558 transistor (from memory check the list though) and also make sure that one of those resistors is 10k not 12k as the diagram displays. also the diode is drawn the right way round there was some confusion of this at one point.

hmm after all this i realized someone needs to remake that diagram.

 

[WILD VR CLUBBY]

that's hardly a hijacking. and the method I said about the constant spray idea in your thread is very basic