Nozzle spray angle...

[parmas]

Originally Posted by jondee86

Hahahahahah... just had a look at what a port injection system costs
So an end to thinking out loud. It is always possible to upgrade, so for now
I will go with a basic two nozzle system... one pre-charger and one post-
charger. Standard nozzles installed at 45 deg in the bends as per the above
sketch.

From what I understand, placing the post charger nozzle further from the
inlet manifold would help the cooling effect, but increase the chances of
water being centrifuged out of the airstream. Placing it in the last bend will
reduce the time for cooling, but allow more water into the cylinders in
droplet form... so perhaps the better option ?

The more the consistency of the injection the less variables you will get. Droplets are only good for cooling the charge while injection is stopped or throttle is closed. The cooling effect is so drastically seen since engine is at no load/off boost (decelaration) and heat is not generated while water is still evaporating into the piping. How much? From 40-15DegC in seconds easily.

As in regards to positioning of the nozzles, I already gave my one cent.

The pre-charger nozzle appears to be less critical as the charger "mixes"
the air and will not be sensitive to droplet distribution at the inlet.

The only question remaining is whether it is necessary to use one (or two)
checkvalve nozzles ? There will be some pressure differential between the
nozzles, so draining could occur during out of boost driving. However, there
will only be about 0.5 metres of 4 mm tube between the nozzles, and this
should not create any significant delay between activation and spray ?

Again, as already explained before if your charger matches your engine and working into it's efficiency eliminate the pre-charger nozzle. Regarding nozzles, I like built in checkvalve nozzles but that is your choice.

EDIT: Oh,and one last question... what would be the recommended water
split be between the pre and post charger nozzles ? 25/75 ?

Trials is your best answer. I would begin with water only to eliminate excess fueling and AFR changes. After that trial, report back to us and we will try to help you in the best way possible

Appreciate the input as I like to examine the alternatives

Cheers... jondee86

Jondee, refrain from asking more questions, you have a good thread to refer on. Read it out slowly and decide from where to begin.

Good Luck!