Re: Homemade Water injection (ideas?)

[James Fawcett <jfawcett@mail.win.org>]

I bought a high pressure inline fuel pump from summit a year or so ago and
have had water injection ever since.  The only problem I have seen is
clogging of my injector for whatever reason.  I think the pumps use
stainless gears so you aren't likely to seize up.  At least I haven't.
Good luck.

James Fawcett
85 5kTQ

On Thu, 9 Dec 1999, Dwayne Cosby wrote:

> I've been considering a water injection system for my 94 S4. With all this
> talk on IC design and water injection on the Quattro motherlist, I thought
> I'd jump in.
> 
> There are 2 basic WI designs:
> 1. Pressurized Reservoir Design
> Reservoir pressurized with manifold pressure and injected with a washer
> pump. This is the most common homemade system, and is what Spearco is
> selling (with a nice aluminum tank). The Spearco kit costs about $150.
> 
> 2. Fancy High Pressure Pump
> This involves using a high pressure (>4 BAR) pump that draws fluid from
> the washer (or other) reservoir, and injecting at high pressures. ERL
> sells a system like this (see link attached) for about $500.
> 
> I like option number #2 since it should provide higher injection pressures
> and a finer mist - But there is no way I'm willing to pay that kind of
> coin for a fancy pump, a $10 pressure switch, and $10 worth of injector
> nozzles. 
> 
> I invision my homemade system working as follows:  
> - manifold pressure switch set to desired boost level (about 14 psi)  
> - cockpit switch to turn on system
> - relay to provide power to pressure switch if cockpit switch is on AND
> washer reservoir low switch is not tripped
> - pressure switch wired to pump
> - when the cockpit switch is enagaged, the reservoir is full, and
> the manifold pressure is above the setpoint, water is injected into the
> cross over pipe just before the intercooler
> 
> Since I use a boost controller in my car, I will wire a set of NO contacts
> off the relay to the scramble signal of the controller to turn up the
> boost a few pounds. I also plan to install an EGT gauge to make sure I'm
> not going overboard.
> 
> The only missing piece of the puzzle is where to source a small high
> pressure pump? Can I use a high performance fuel pump or will water cause
> it to sieze?
> 
> Any other suggestions or ideas?
> 
> For those who don't like the idea of water injection, I suggest you have a
> quick look at the attached link for actual performance results and
> articles:
> 	http://www.mstiusa.net/MR2/Water.html
> 
> Thanks,
> Dwayne Cosby
> 94 S4
> 
> >>>
> From: Trevor and Cara Frank <tcfrank@home.net>
> Subject: ERL Aquamist water injector
> 
> I have looked at these things in the past but have no experience with
> them.  I came across this system a while back when looking at components
> that major rally teams ran.
> 
> One of the U.S. distributors
> http://www.f-max.com/ERLH20.htm
> 
> 
> http://www.aquamist.co.uk/
> <<<
> 
> 
>