Hi,
I'm looking to fit a boost pressurised pre compressor water injection setup onto my VW 1.8T which runs the small K03s turbo. The turbo is way outside its efficiency range and so is producing a lot of heat so I wanted to use this system as a way to use wet compression to make the turbo a little more efficient and 'act bigger' and also keep post comp temps down from where they currently are.
Here it is being bench tested @ 1 bar of compressed air as a 'boost source':
https://www.youtube.com/watch?v=FuViQ0hmiS0
and here its being tested to see how the droplets travel through a tube:
https://www.youtube.com/watch?v=qC5-ysVo1es
I think those droplets will sail through if switched on at about 10psi.
The nozzle is a spraying systems SUE15B. Threads on here seem to suggest that you need to inject water to the tune of 10-15% of total fuel flow.
I have 380cc injectors that are operating at 85% duty cycle when flat out. 85% of (380cc X 4 injectors) = approx. 1292cc of fuel flow max. 10% water of that = 152cc/min, 15% = 228cc/min.
My nozzle runs:
5psi - 1.0 gal/h = 75cc
10psi - 1.4gal/h = 105cc
20psi - 2.0gal/h = 151cc
So with this nozzle it looks like at 20psi (which is the boost peak), i'll be at 151cc which is on the min of the suggested range of water to inject =10%.
So first up, do those calcs look sound?
If correct and given that I am on the lower end of the ideal range for pre comp injection, does it stand to reason that I can also then run another pumped nozzle downstream if need be to achieve a better water:fuel ratio?
Now a hardware question. Not sure if you can see from the short vids, but there is a one way valve on the boost signal line. I'm thinking that when under vacuum that will close preventing the plenum being able draw the reservoir into vacuum OR draw air in reverse through the nozzle representing an air leak. Am I correct in setting it up that way - I don't need a 1 way valve anywhere else?
thanks for any help
sam