water injection Options

[awd4kicks]

There are some very informative sites on this issue.

Personally I have only seen 60psi and 100psi pumps used. I'm sure some vary, but I'm running a 60. Seems to be plenty so far. I'd be leary of the fuel pump because gas doesn't cause oxidizing like water.

Are you sure that you need water injection? It's used to reduce heat and knock, allowing you to turn up the boost. Promblem is you still have to have enough fuel to feed the fire, if you don't then turning up the boost isn't an option and the water would be wasted money. The only reason I say that is because I thought that fuel delivery was the 3S's limiting factor at 14-15psi.

Marcus

[awd4kicks]

Actually, when your EGT's are too high, it's more advisable to spend the money for injectors and fuel control or turn the boost down.

The water should cool the air charge down before it gets to the combustuion chamber, and I have heard that it cools the exhausting gasses as it uses energy to turn the water vapor back into a liquid. The bad side effect to water injection is that it takes up space normally ment for gas and air. So what it does, is slow the burn which makes a cooler combustion at the cost of performance. The only thing that makes it worth while is to offset the lesser performance by pumping up the boost. This is also the same theory used when you put in race gas. It actually burns slower (less performance) than regular gas, but allows you to add boost and or timing to make up for and increase upon the difference.

So if you don't have the fuel to turn up the boost, you may actually be making your car slower. That's what I meant by a waste of money. Not for safety sake, because a slower less performance oriented burn will definitely be safer for your engine.

Take all this melarky with a grain of salt, because I'm going by memory. Nate and/or Kris may be able to shead more light on this.

Marcus
[Gee, after re-reading my reply I'm thinking I should take my own advice! :roll: ]

[wortdog]

Marcus is right about the water being a solution mainly for knock. If your EGT's are too high, you need either an adjustable fuel pressure regulator or bigger injectors.

Or you could run an alcohol/water injection setup with denatured alcohol (ethanol) or methanol. Both of these have around a 100+ octane rating as well as having almost the same cooling effect as water. Downsides include flammability, and methanol is pretty corrosive. Most of the Buick guys I've talked to seem happiest running 100% denatured while tuning their fuel back a bit.

The system on my car has a 90PSI pump out of a mid 90's F-150. Lifetime warranty at Autozone, around $90 I think. It worked well until the check valve locked up, and I decided the problem was with the nozzle and took a drill bit to it. :roll: Needless to say it doesn't mist very well.

I'd really like to retro-fit some 2-3 large Aquamist nozzles on the system as well as an in car PWM for controlling the output of the pump.

[natedogg]

Dan you emailed me about this about 3-4 weeks ago, remember? I gave you all the info you need. I basically said what Marcus and Eric are saying now. You need fuel not water (I think that goes for Marcus also :wink: ). Running lean is the reason for your high EGT's.

Not to be picky but to make a correcting modification to Marcus's statement, it takes energy to turn atomized liquid water into water vapor. Gas is a higher energy phase than liquid as liquid is to solid.

[awd4kicks]

GEEZ...simmer down there Nate. We all know you have nothing to do at work but read DSM technical articles :wink: , but a guy has the right to check other opinions. He's just trying to find somebody as crazy as him, right Dan?

[natedogg]

:shock: I think you mistook my tone Marcus. I was just reminding Dan that I sent him some info a while back in case he forgot. I guess it came out wrong.

I don't have fifths of tequila to down here at work so I have to occupy my time in other more sober ways. :wink:

Mmmmm...tequila injection. Performance for the mind.

[Mike]

I want bigger injectors!!!! the biggest ones pleeeze! :twisted: i would be glad to work extra then!

[awd4kicks]

Peace DAWG! If you ever need some of that Tequila you know I'll share and give you a tour too!

[natedogg]

Alright man. But if it hurts your performance, don't say we didn't warn you. :wink:

[natedogg]

Dan its obvious to me that you're still missing the point of water injection. High EGT's at high mph isn't a symptom of you not having water injection, its a symptom of not having enough fuel. You're running lean. Spend your money on supporting fuel mods first and after that if you still need it, consider water injection. Water is not a replacement for fuel. Water injection systems are designed with fuel requirements in mind. I you're not getting the right amount of fuel right now, then you won't be getting the right amount of water from the injection system because it is based on your already lean fuel condition. Give me a call sometime and I'll try to explain it a little better because I'm not getting my point across to you this way.

Bogging your engine down with water at WOT is the last thing you want to do. You only want water when your at full boost. WOT does not mean full boost. As you know, it takes a small amount of time for a car to reach full boost after the pedal is pushed to the floor. This is the reason for the MAP mod on the SAFC that Josh has done and Kris and I are doing to our cars. Fuel tuned on boost rather than throttle position. IMO, this is what you need, not necessarily water injection.