944 Turbo: Water injection + intercooler sprayer
07-19-2005, 10:27 AM
#16
Three Wheelin'
I wish I had my camera, my brother took it with him on vacation.
I had completely set up a port water injection system, manifold was made, installed, pump plumbed, etc, before I crashed the car last winter. I still have the setup but never got to test it.
The nozzles I had were very expensive, normally meant for spraying oil in some oil burner or something, they had the correct flow rate @100psi to have one in each intake runner and flow 15% for every 100% fuel. I was going to have it turn on at 15psi w a pressure switch, back when I was still in the "the stock turbo can make 20 psi to redline" mode of thinking.
Now the pieces just sit in the garage waiting for a project car..
Also, do not use that location at the TB! Water droplets have a lot more inertia than air and will no way make it down the first intake runner, and the engine is only as good as the weakest cylinder.
I had completely set up a port water injection system, manifold was made, installed, pump plumbed, etc, before I crashed the car last winter. I still have the setup but never got to test it.
The nozzles I had were very expensive, normally meant for spraying oil in some oil burner or something, they had the correct flow rate @100psi to have one in each intake runner and flow 15% for every 100% fuel. I was going to have it turn on at 15psi w a pressure switch, back when I was still in the "the stock turbo can make 20 psi to redline" mode of thinking.
Now the pieces just sit in the garage waiting for a project car..
Also, do not use that location at the TB! Water droplets have a lot more inertia than air and will no way make it down the first intake runner, and the engine is only as good as the weakest cylinder.
07-20-2005, 01:45 AM
#19
Three Wheelin'
Originally Posted by Dark's WI Page
beyond that I hope to install a blow-through MAF on my car's upper intercooler pipe and hotwire mass airflow meters don't like large quantities of water sprayed into them
I was thinking, one of the rear cubbies might be an ideal place to mount the tank and pump. Unused space normally. You'd have to run a pretty long pressurized water line, but that shouldn't be too much of a pain. $3 worth of hard nylon tubing.
About the fast acting solenoid - apparently the one from MSD...
...is up to the task of operating around 1kHz, and only $98 retail. They're working on finding a discount (non MSD-branded) source here...
http://www.msefi.com/viewtopic.php?t=7879
07-20-2005, 05:34 PM
#20
Alright, I'm starting to reassemble the car. I plan on taking a bunch of pictures so that I can document all of this in a complete how-to tutorial but I have a question for the guys interested in using such a tutorial:
Do I need to take individual step by step pictures (this bolt goes here, that bolt goes there) or will pictures of major steps (here's the water pump mounted, here's the power steering cooler back in place) be sufficient?
Do I need to take individual step by step pictures (this bolt goes here, that bolt goes there) or will pictures of major steps (here's the water pump mounted, here's the power steering cooler back in place) be sufficient?
07-20-2005, 07:20 PM
#21
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In my best Forrset Gump voice: Lt Dan...where does this go?...Dude take pictures of EVERYTHING! seriously. Then again, if yopu want to spend a few weeks answering all of my dumbassed questions, just take pics of the major stuff. TIA
07-22-2005, 07:06 PM
#22
Race Director
I have been meaning to chime in on this thread... I picked up this pump last month. I am going to mount it where the distributor was so it will be in direct line between the water res and the IC pipe. The nozzle will be mounted after the BOV and the pump will be controlled by a PWM function on a Link Plus computer. I think its best to base the water flow based on injector DC as the water % should be based on fuel flow, and from what I have read around 20% is the norm. That way at say 5psi you can start the water flow and keep it in proportion (heat from the turbo really ramps up here)... I think I will do this after the GT35, exhaust and intake manny are done...
08-07-2005, 09:36 PM
#25
UPDATED: http://www.darklightning.com/gi/951wi.htm
Pump installed and functional. Now just need to install a boost switch and I'm pretty much done.
Pump installed and functional. Now just need to install a boost switch and I'm pretty much done.
08-08-2005, 04:24 AM
#30
Nope.
And before you jump on my case, let me explain. This simple setup was designed to as an on/off, 0% / 100%, nothing or everything system. I'll add an Aquamist (or other) fast acting solenoid later for fine tuning but even then controlling the IC sprayer and the water injection at the same time will work just fine. Why? Because there's so much frickin' water from the two 1.0mm IC nozzles that it wouldn't hurt to have a bit less. Regardless, in the mean time this setup will work for my purposes.
If you look at a 944 turbo's fuel injector duty cycle with a K26 @ 18 psi, you'll see that once its spooled to 18 psi the fuel injector duty cycle is relatively flat until redline and/or shifting. I don't know my exact injector duty cycle but I do know my airflow values (using my datalogger) and airflow has a direct relationship with fuel injector duty cycle at wide open throttle. Well, it has a direct relationship with at every throttle point but that involves tables of values. At wide open throttle it's an easy 12:1.
Assuming a roughly 75% duty, that equals:
36lb/min x 4 x 0.75 = (roughly) 400cc/min x 4 x 0.75 = 1200cc/min total fuel delivery.
The 0.8mm nozzle provides roughly 245cc/min @ 5.5 bar. ShurFlo pump provides 100 psi (7 bar) but the actual effective water pressure is pump pressure minus boost pressure so in this case 100 psi - 18 psi or roughly 5.5 bar.
245cc/min of water is approximately 20% of 1200cc/min of fuel, a perfectly acceptable amount.
And before you jump on my case, let me explain. This simple setup was designed to as an on/off, 0% / 100%, nothing or everything system. I'll add an Aquamist (or other) fast acting solenoid later for fine tuning but even then controlling the IC sprayer and the water injection at the same time will work just fine. Why? Because there's so much frickin' water from the two 1.0mm IC nozzles that it wouldn't hurt to have a bit less. Regardless, in the mean time this setup will work for my purposes.
If you look at a 944 turbo's fuel injector duty cycle with a K26 @ 18 psi, you'll see that once its spooled to 18 psi the fuel injector duty cycle is relatively flat until redline and/or shifting. I don't know my exact injector duty cycle but I do know my airflow values (using my datalogger) and airflow has a direct relationship with fuel injector duty cycle at wide open throttle. Well, it has a direct relationship with at every throttle point but that involves tables of values. At wide open throttle it's an easy 12:1.
Assuming a roughly 75% duty, that equals:
36lb/min x 4 x 0.75 = (roughly) 400cc/min x 4 x 0.75 = 1200cc/min total fuel delivery.
The 0.8mm nozzle provides roughly 245cc/min @ 5.5 bar. ShurFlo pump provides 100 psi (7 bar) but the actual effective water pressure is pump pressure minus boost pressure so in this case 100 psi - 18 psi or roughly 5.5 bar.
245cc/min of water is approximately 20% of 1200cc/min of fuel, a perfectly acceptable amount.