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Old 04-28-2012, 01:55 AM   #175 (permalink)
bazman
EcoModding Lurker
 
Join Date: Apr 2012
Location: New Zealand
Posts: 46

Weird Thing - '00 Holden (GM) Commodore SS Series II
90 day: 18.67 mpg (US)
Thanks: 14
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Quote:
Originally Posted by t vago View Post
I don't think anyone here has done so.



For straight gasoline, maximum fuel economy is seen at an AFR of 17:1.



Cost? If the water injection setup could be done cheaply enough, then it'll still be an attractive option.

It would help to quantify the fuel economy gains for this mod. If, for instance, the modification resulted in a 10% gain in fuel economy for my truck with a 19 MPG baseline, and my driving style (120 mile commute using mostly highway driving), I would consider it to be worthwhile.

Then again, for somebody who gets 30+ MPG, it might not be so attractive.



It definitely would help, but the key is to have an engine tune that takes advantage of water injection. The idea is the same as for boosted applications.

The trick is, as you have pointed out, how to vary the flow. I am assuming that you'd use a water pump variable controller to do this. Fuel injectors are reported to quickly corrode, except for those injectors with stainless steel internals.

Many years ago, when I was planning to install a turbocharger into my Sebring, I had bought a water injection kit, along with numerous solenoid valves and different sized water injection nozzles. Each nozzle was sized to allow roughly twice as much flow as the next smaller one. I was going to design a circuit that would have switched these nozzles on and off such that the engine under boost would have received roughly the same amount of water per cylinder for any given engine speed.
Thank you for your informative and intelligent response.

I'm going to look at various kits including the ERL Aquamist (ran them before and they work great), Devils Own, Snows and some new ones I've not heard of before like Hydramist that uses Aquamist components. There is also this one that uses a mechanical pump to force the water to atomize rather than an electric high pressure pump...

Last edited by bazman; 04-28-2012 at 02:22 AM..
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