Dark Lightning

Just food for thought:

http://www.darklightning.com/gi/951wi.htm

It's still a work in progress so keep the flames to a minimum. Things of note:

• Removing the 'small' washer fluid tank is easy. Installing the 'large' tank is a frickin' pain.
• Finding a place to physically install the massive Shurflo pump is a challenge. Ideally it should be located BELOW the water source for the best possible performance; I have a few ideas and I'll snap some pics later.
• If you have a friend who can weld aluminum, you can do some cool things for mounting the intercooler sprayer(s). Pics to follow I promise.
• Did I mention the water tank was a pain?

J Chen

Hey Dark,
Great effort. Keep us posted.

DanG

Looks good John! I have a Shurflo anxiously waiting the arrival of my 951 already. I'll leave it on the shelf until the car is megasquirted though.

One comment... you might consider mounting a single injector further back in the cold side IC pipe for better mixing/dispersion. I could see the spot you chose giving you inconsistent results for each cylinder. I think you want about 3-5 "diameters" in tube length between your injector and the first intake runner to ensure complete mixing. Heck,you might even be able to mount the injector on the IC's cool side endtank, just before the start of the IC tube. That should give maximum mixing/cooling.

About the IC sprayer, what kind of operating conditions would you have it spray? Same as the H2O inj? Or just on a manual switch? Or some other logic based criteria?

Dark Lightning

This was a concern of mine as well. The other advantage of mounting to the IC (besides dispersement) would be the fact that all of the water injection plumbing would be hidden, leaving a much cleaner installation (visually). Unfortunately there are no good mounting spots on the IC; too bad the end tanks weren't square.

For the sake of my budget I currently plan on the WI & IC spray coming on at the same time, triggered by a simple Hobbs switch set at ~12psi. I see some electronic controls and solenoids in the future to fine tune everything.

DanG

Have you seen Eric Fahlgren's (Mr. Megatune) H2O info site?

http://www.not2fast.com/thermo/water_injection/

I really like his idea of using those instant fittings...



So are you going for the 'pump feeding a veggie mister nozzle through a vaccum solenoid' method of on/off control? Click the 'part' or one of these two links for good DIY sites... one two. That is the style of system I test fitted on my turbododge, although the MSnS-E controlled injector/fast acting solenoid sounds like it might be even better...



It actually blips your water injector with the same pulse as an injector. Idea being that if you size your water injector to flow the proper ~15% water to fuel ratio, then it should inject this 15% on a continuously increasing curve, directly in line with the fuel injectors. Cool stuff!

Dark Lightning

Unfortunately fast-acting solenoids such as what they're using are EXPENSIVE.

I'm using quick disconnects except for the tank-to-pump line which will be a (relatively) large diameter. My hardware pile:

Dark Lightning

"High speed stainless inline valve", US$232 - http://www.aquamist.co.uk/sl/plist/p...4/806-244.html

DanG

Yup, that sure is expensive. I was under the impression there was a pretty workable option for around $90. I'll dig up some more info tomorrow.

Dark Lightning

For what it's worth, McMaster Carr nozzles don't have as good of a spray pattern as the Aquamist products. When the McMaster Carr nozzles cost US$2.50 and the Aquamist nozzles cost US$19 you have to wonder. It's your motor, do what you want, but I went Aquamist.

Second note is the ShurFlo pump: get the 100psi version. More pressure = better spray. Again, it's your motor.

Dark Lightning

My how-to has been updated. More pics available at: http://www.darklightning.com/gallery/88951engine

Thanks.

DanG

Also, I think I remember reading somewhere about a guy using a plain old fuel pressure reg to at least hold the pressure at the nozzle constant relative to boost, instead of it dropping (constant absolute pressure). The other common method was to plumb a boost line into the main resevoir, or a separate accumulator, like in some of those links I posted.

A "dumb" system can definitely be tuned in pretty well. Sure it won't be as accurate as the $200 aquamist solenoid based system, but H2O injection is a much less exact science than say air/fuel ratios.

Your parts look cool. I'm definitely going to use instant fittings for my system as well. Have you "test fired" a veggie mister nozzle yet? They atomize pretty darn well and over the full range of pump pressures. Instant fog. My engine is going to love it. Only the best for my baby, right?

Dark Lightning

But if you think about it, how much does boost really change? Say you do all of your math for 15psi of boost. If you have the water injection only activate above 12psi boost and you don't peak over 18psi, you're only talking about a +/-3psi pressure swing. And 3psi out of 85psi (100psi from the pump minus 15psi pushing backwards due to boost) ain't much to worry about.

Yeah, I had water injection on two previous cars and had a pretty good time with it.

DanG

Haha, I just posted the opposite! I haven't tried an Aquamist nozzle though. I can imagine a side by side test would have me leaning toward one of those as well.

I did get the 100psi pump, it was barely any extra money, capable of considerably more pressure. Although it is an extra pound heavier.

Good thing about H2O systems is typically they'll fail by not flowing enough (corrosion), instead of by flowing too much. So keep an eye on the intake air temps and you'll have a pretty good indication on how everything is running without too much danger to the motor. Assuming you have working knock sensing/timing retard.

DanG

True. My experience was helping a buddy get a system going with the 60 psi pump on a DSM running upwards of 24 psi boost. He switched it on around 8-10 psi, so he was looking at a ~14 psi change over 60 psi max pressure, or around 25%.

Ski

It would better for atomizing the water IF you could get your inlet feed out of the intake and into the intercooler pipe or the end of the intercooler. That way, the water has a much better chance of mixing with the air, just a thought from previous systems and aquamist systems.

I'm rigging up an intercooler sprayer on the track car - 80 psi pump and two nozzles. It will operate off of a pressure switch set for 14 or 15 psi - therefore mainly used on the straights at TWS, Memphis, Barber, and the small two at Hallett.

If you remove the inner fender liner that opens up some space above and behind the brake cooling inlet to mount a bracket as well. Looks great BTW.