RomRaider

make sure that after tuning you monitor your AFs in all gears. Spraying via boost will give different AFRs in different gears. I can provide a link to discussion if necessary.

great little write up. explains a few things i was wondering since i started considering a meth/alcohol spray setup.

so that explains the meth side of things.. what about if i want to spray denatured alcohol and water instead of meth and water? i hear alcohol is a little better than meth though i think a little more expensive to buy.

as for making a kit yourself... i found this site which explains alot about building one yourself. http://www.turbomirage.com/water.html

I'm about to spray 100% with one of the smaller nozzles.

A little nervous, not going after max power, just mainly want a detonation inhibitor, and a little more HP on top of that.
If the injection system fails i shouldn't lose an engine so easily, as i won't tune on the edge....

thoughts? Sounds like a plan?

Just note what your afr is while not spraying and what it is while spraying. Technically if you were spraying the alky through the injectors at same pulse width your afr would go lean but your not. Your spraying it separately on top of what injector fuel you are spraying. That's why the wideband will show rich. Don't run your afr off spray leaner than you would normally and you leave slight room for error.

There really is no safe aproach if your trying to figure in safety in case of pump failure without having a flow meter and some type of failsafe to cut boost control in case of low alky flow.

This post is proving very valuable to me so thanks for the right up.
I've got an AEM methanol/water kit ordered.

I've two questions, the kit comes with 3 nozzles - 250cc/min, 500 cc/min &1,000cc/min
Witch size would you say start with? For a stage 2 ej207 vf35

My second question is i have a AEM failsafe wideband that will cut power to a relay ect if afr drops lean or rich. In my mind this would be the best possible way to keep the system safe If there is a spray problem. By having the wideband failsafe cut boost or map switch to a non meth map (carberry rom) when afr dips lean seem a good way run safe? Would it map switch at WOT? Would it be better/quicker just to cut boost via the boost solenoid?

anyone tuned with 100% water injection only?

i've installed an aquamist hsf3 kit injecting water only. car was tuned previously before the kit was installed.

2 days back i did a power run on the dyno with and without the water injection kit on without any changes to the tune. i noticed that with the water injection on, the ecu was detecting knock and pulled timing at the higher rpm range. turned the water injection kit off and the car was pulling great all the way till redline with no knock or timing pulled.

could it be with the added water, the cylinder compression ratio increased hence knocking? since i didn't notice any changes to the AFR with and without water.

That is kind of strange not to see any change in afr. I bet the car is running lean with the water on. I have seen 1 full point leaner afr with a medium aem jet. e.g. tune at 10.9 I will see 11.9 to 12.0 with only injecting water.