Direct Port Nozzle Location
 

I'm considering the following setup:

Aquamist HFS-3 with nozzles in the UIM runners and a nozzle pre-compressor. I plan on injecting pure water, and here's a summary of the rest of my system:
- 13B-RE, street-ported w/FD rotor housings
- 4 X ID1000 injectors @ 75 PSI (flow equivalent to 4 X 1200cc at 43.5 PSI)
- GT35R
- Large FMIC
- Large dual cone air filter mounted in front of the FMIC, w/4" dia clean air duct to the turbo inlet


Q1: Is it better to inject into the UIM primary or secondary runners? They'll both be flowing air when I'm injecting, and locating the nozzles is just as easy in either location.

Q2: The injection in the UIM secondaries is immediately above the brake vacuum port. I know I won't be spraying when the system is under vacuum, but I have to ask the question to the experienced members: Will this cause any issue?

Q3: For the pre-turbo injection, which is the best direction? Perpendicular to the airstream (typical), or down the throat of the system (injector mounted in air cleaner)? In my system, the air cleaner is about 2 feet upstream of the turbo inlet.

Q4: I plan on running -4AN lines to the nozzles. Does anybody know of a good brass or stainless distribution block? I want these materials to protect for running alcohol in the future.