Welcome to the North American Subaru Impreza Owners Club Wednesday October 1, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Engine Management & Tuning

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 04-04-2005, 11:17 PM   #1
The Deliverator
Scooby Specialist
 
Member#: 42376
Join Date: Aug 2003
Chapter/Region: Tri-State
Location: Buffalo
Vehicle:
2006 92x Aero
Midnight Black Metallic

Default Homebrew fully-programmable water injection system

I've been flirting with the idea of adding water injection to my stage 2 wrx.

The typical homebrew type kits (shurflo, etc) are what got me interested, but after I learned more they don't really do it for me. It just seems to me that there should be some sort of proportional increase in amount of water injected relative to boost and/or rpm. Dual stage? Still not for me.

Aquamist 2d looks really nice and seems like it would do what I wanted. Expensive, though. The fully programmable one seems better still, but that costs more still.

So I've thought about how to make a better homebrew system. And I've arrived at what I think would be a pretty robust system (and a fun exercise to implement).

Start with a megasquirt . It's a complete fuel injection computer that you build yourself; costs about $180 for the parts. The tuning software is free.

Use it to control a single fuel injector that'll do water and/or alcohol, mapping against boost and/or rpms. The injector needs to be safe for water and/or methanol. Information on injectors that are safe for methnaol was surprisingly hard for me to track down. Injectors for water proved impossibe to find, with the exception of a million references to the Aquamist HSV. I ended up finding the Edelbrock Pico 3574 ($60)and stopping there. Anyone know if it'll rust if it runs just water?

Other parts:
$100 Shurflow pump
$60 Pressure accumulator (so there'll always be water at a fairly consistent pressure)
$40 Flow sensor (between injector and accumulator)
Magic to make the car run wastegate pressure if the flow sensor shows the water's stopped

Add a tank, some wire, some tubing...

Ok, so there's the idea for a slicker-than-snot-on-a-doorknob fully programmable water injection system for a total of... $440 so far.

It'll be a month or three before I start trying to actually build one of these, but I thought I'd throw the idea out here in case some of you would get interested and would like to help flesh it out. Where to find stainless injectors, the details of the magic needed to limit boost to wastegate pressure in the event of flow stopping, etc.

Any suggestions? Ideas for fleshing out the system? Flaws in the plan? You're welcome to take the idea and run with it; you're quite welcome to go ahead and beat me to the implementation. Just please give your ideas/solutions back to this thread.
* Registered users of the site do not see these ads.
The Deliverator is offline   Reply With Quote
Old 04-05-2005, 01:42 AM   #2
fragment
Scooby Specialist
 
Member#: 8050
Join Date: Jul 2001
Chapter/Region: W. Canada
Location: Bugeye EJ207 - T3T04S
Vehicle:
2007 Wagon VF36

Default

I've thought about something similar. But why have the complexity of the controller? I was thinking that a driver tapped into one of the injector signals would be the way to go. Automatic variation based on load. Then you just need to adjust either pressure or injector/nozzle size to get the flow where you want it.

I was thinking of using one of my take off blue injectors to see if it would be corrosion resitant to a water/methanol mixture, but I've re-used them on another project.
fragment is offline   Reply With Quote
Old 04-05-2005, 03:02 AM   #3
bboy
Scooby Specialist
 
Member#: 56468
Join Date: Mar 2004
Chapter/Region: NWIC
Location: Seattle, WA
Vehicle:
04 Improved STI
Dirty White

Default

More power to ya. I've been looking at the same stuff. There are micro controllers out there for pretty cheap, but hooking in the RPM feed is pretty tough. I too looked at the Megasquirt, but for the really cheap route you are building the thing yourself.

I've looked at used e-Manage as an option. You can pick those up in the $250-300 range, but for that money I'd rather have the Aquamist MF2.

Here's the best scenario I can come up with for a cheapo 3D system. Use the FIA2 to ramp up water injection according to RPM. They are about $150. Then if you want different levels of WI at different levels of boost plumb in 2-3 pressure switches. As boost increases you open up more lines of water flowing into the same nozzle. You can get a pressure switch (Hobbs) from NAPA for less than $20.

Let's say you set WI to be 10% of fuel with the FIA2 for boost levels of 5-12 psi. At 13 psi, you open a pressure switch that now ups WI to 15%, at 18 psi a second pressure switch opens, and now you have 20% water:fuel. The whole time the FIA2 is keeping the water:fuel ratio in line with RPM. Now you have a 3D system that is responding to RPM and boost, plus you have the failsafe feedback from the FIA2 if a jet gets blocked or pump busts a leak--whamo boost cut to your boost control solenoid.

With the pressure switches you can either open new lines downstream of the FIA2 that feed the same nozzle(s) or you can open new nozzles to spray.

Mix and match and it would really be pretty versitile.
bboy is offline   Reply With Quote
Old 04-05-2005, 03:19 AM   #4
0db
Scooby Specialist
 
Member#: 33879
Join Date: Mar 2003
Chapter/Region: SCIC
Location: Santa Barbara, CA
Vehicle:
2003 WRX Sporkwagon
Black

Default

is a single fuel injector the right choice? what percentage of fuel volume do you want to flow with water? I've got extra injector drivers on my AEM and extra 450cc injectors sitting around, I could pull something like this together proper quick if that's all I need (aside from a pump and such)
0db is offline   Reply With Quote
Old 04-05-2005, 01:08 PM   #5
bboy
Scooby Specialist
 
Member#: 56468
Join Date: Mar 2004
Chapter/Region: NWIC
Location: Seattle, WA
Vehicle:
04 Improved STI
Dirty White

Default

Fuel injectors are very rust sensitive. There are some liquid handing solenoids other than the Aquamist HSV, but I think that's a reasonable choice as well. Unfortunately the current currency exchange rate makes Aquamist product more expensive than they used to be. Grainger.com has the most solenoids for sale, but omega.com also carries quite a few.
bboy is offline   Reply With Quote
Old 04-05-2005, 01:47 PM   #6
beefyib123
Scooby Newbie
 
Member#: 55811
Join Date: Feb 2004
Default

^^^ i don't think that an fuel injector will hold up to water either. here is a system that i built.... http://www.wrxfanatics.com/index.php?showtopic=28677

If you have a UTEC then use it to control the system other wise instead of using your fuel injector controler to control an injector use it to open and close the solenoid. OK SO actually you would use it to open and close a RELAY which would open and close the solenoid but you get the idea. PM ME if i can be of anyhelp. i am going to the dyno on THU. so i will have some #'s to post of just how much the WI can add.

***FIXED LINK****
beefyib123 is offline   Reply With Quote
Old 04-05-2005, 02:03 PM   #7
PHATsuby
Scooby Guru
 
Member#: 13617
Join Date: Dec 2001
Chapter/Region: MWSOC
Location: MN
Vehicle:
2001 Legacy GT back
to stock is a project too

Default

Quote:
Originally Posted by fragment
I've thought about something similar. But why have the complexity of the controller? I was thinking that a driver tapped into one of the injector signals would be the way to go. Automatic variation based on load. Then you just need to adjust either pressure or injector/nozzle size to get the flow where you want it.

I was thinking of using one of my take off blue injectors to see if it would be corrosion resitant to a water/methanol mixture, but I've re-used them on another project.
this is a good idea for the variation of output, but wouldnt you be stuck at a fixed percentage of water/fuel? like, lets say you just added another stock injector size(not that you would) that would mean you are always 20% water(1/5).

Ben
PHATsuby is offline   Reply With Quote
Old 04-05-2005, 02:38 PM   #8
The Deliverator
Scooby Specialist
 
Member#: 42376
Join Date: Aug 2003
Chapter/Region: Tri-State
Location: Buffalo
Vehicle:
2006 92x Aero
Midnight Black Metallic

Default

This idea grew out of certain assumptions:
1) Proportional, tunable water injection is the way to go. Need a high speed valve or injector and a mappable injector controller to ensure the propper proportion of water:fuel.
2) The system has to be fail-safe. In the event of controller failure, the injector must default to being closed (no hydrolocking the motor, thanks). In the event of a blocked jet, boost must be cut (no running WI optimized Air/Fuel ratios without I'ing the W)

3) I'm cheap, so unless I can get a 2d for, say, $600 homebrew is the way to go

I picked the megasquirt as a good choice for the controller because:
4) It's cheap, and readily available so other people can make the same kit for themselves. And most people that aren't capable of building it themselves can probably bribe someone else to build it for them.
5) Consistent pressure, not having to run the pump all the time, and not having to wait for the pump to start pushing water are all Good things. System has to have an accumulator.

If you disagree with...
Assumption #1 Get a single or dual-stage shurflo-based kit
#2 You're insane. Start saving for a new motor.
#3 Get a 2d or 2s.
#4 Build it with whatever used injector controller you can find on ebay
#5 Build yours without the accumulator

Buying choice bits from the 2d could be nice- fia2 seems sweet, and a bargain at $100 list price. But my understanding is that it only drives the HSV ($180 list price). And if you want to use it's clog-detection bit, I believe you have to use the aquamist pump. Congrats, you just bought a 2d, piece by piece, for (I think) more than the cost of the complete 2d kit. Now go buy an accumulator and a tank.

The kit that includes the mf2 looks even better, but costs over $1000. If I have to make a custom map to get the functionality I want, I'll do it on a setup that cost half as much and that I had the satisfaction of building myself.

I'm not married to the megasquirt, just the cheapest thing I found which will do what I want. I'm open to ideas for other cheap, functional injector controllers. Used ones are cool and all, but if I'm going to build this I'd like to do it with readily available parts so others can do it too.

So anyone know where we can get a fuel injector that's safe for water and/or methanol besides the Edelbrock pico's? Or if the pico's really are safe water?

How about specifics on how we'd cut boost in the event of WI system failure?
The Deliverator is offline   Reply With Quote
Old 04-05-2005, 02:51 PM   #9
driggity
Scooby Specialist
 
Member#: 7453
Join Date: Jun 2001
Chapter/Region: TXIC
Location: Grapevine, TX
Vehicle:
2005 Legacy GT Wagon
2006 LJ Rubicon

Default

Quote:
Originally Posted by PHATsuby
this is a good idea for the variation of output, but wouldnt you be stuck at a fixed percentage of water/fuel? like, lets say you just added another stock injector size(not that you would) that would mean you are always 20% water(1/5).

Ben
If you adjust the pressure of the water injection system you should be able to adjust the total flow.

Quote:
Originally Posted by stanh04wrx
How about specifics on how we'd cut boost in the event of WI system failure?
It shouldn't be too hard if you're using some method of electronic boost control (factory or aftermarket). I'd think that you could wire up your failsafe so that when it registered a fault it would cause the boost controller to allow the wastegate to see full pressure. You'd probably just have to wire up some sort of relay to do this. If your engine management is set up so that at wastegate pressure and below it runs timing and AFRs that are safe without water injection it should be a pretty safe system.
driggity is offline   Reply With Quote
Old 04-05-2005, 04:24 PM   #10
CMJ
Scooby Specialist
 
Member#: 39235
Join Date: Jul 2003
Location: L.A., CA
Default

You should try the Lucas disk type injector; they are made with all stainless internals.

Most of the solenoids on the market do not even come close to the HSV's 250hz operating range.
CMJ is offline   Reply With Quote
Old 04-05-2005, 05:00 PM   #11
RiftsWRX
Scooby Guru
 
Member#: 6124
Join Date: Apr 2001
Chapter/Region: MWSOC
Location: Glendale Hts, IL, USA
Vehicle:
2000 NFR AP1 S2000
'07 Honda FIT sport (5MT)

Default

I'm toying with the idea of using my labtronic water spray controller as a more robust, yet still basic water injection controller.

I currently use my UTEC, but since the UTEC cuts the MAP signal to the stock ECU (using a flash currently) it throws off reporting, logging, etc. As well as boost control.

Worse case, I may just go with a stupidly simple pressure switch.

EDIT: Though... http://www.autospeed.com/cms/A_2471/article.html <-- Let your imagination run for a little bit with this one gentlemen..

Jorge (RiftsWRX)
www.ProjectWRX.com

Last edited by RiftsWRX; 04-05-2005 at 05:24 PM.
RiftsWRX is offline   Reply With Quote
Old 04-05-2005, 11:10 PM   #12
Blennophobic
Scooby Specialist
 
Member#: 25886
Join Date: Oct 2002
Chapter/Region: E. Canada
Location: Ottawa area
Vehicle:
2003 WRX Rally Blue
- sold, waiting for 2015s

Default

Read this:

http://www.snowperformance.net/default.asp

and this:

http://www.musclemustangfastfords.com/tech/0407mm_snow/

I bought the Stage 2-MAF system especially because it uses the MAF signal to ramp up water flow... the best way to go in my mind because MAF is a good proxy for engine power output.

Now if I could only get my dang battery relocated to make room for the tank and pump I could install the system

Steve.
Blennophobic is offline   Reply With Quote
Old 04-05-2005, 11:31 PM   #13
Uncle Scotty
Scooby Guru
 
Member#: 16200
Join Date: Mar 2002
Vehicle:
OK Houston
we have an Uncle

Default

Quote:
Originally Posted by Blennophobic
Read this:

http://www.snowperformance.net/default.asp

and this:

http://www.musclemustangfastfords.com/tech/0407mm_snow/

I bought the Stage 2-MAF system especially because it uses the MAF signal to ramp up water flow... the best way to go in my mind because MAF is a good proxy for engine power output.

Now if I could only get my dang battery relocated to make room for the tank and pump I could install the system
Steve.
I put mine under the passengers seat......


...and my idea is to use the 12L tank that goes behind the rear seats to fill a 4-6L tank, using the low pressure pump that comes with the 12L tank, that is in the battery space.....to feed the HP pump.....and maybe something like this....
http://www.autospeed.com/cms/A_0589/article.html

....to control it if I don't use the UTEC....
Uncle Scotty is offline   Reply With Quote
Old 04-06-2005, 07:00 AM   #14
RiftsWRX
Scooby Guru
 
Member#: 6124
Join Date: Apr 2001
Chapter/Region: MWSOC
Location: Glendale Hts, IL, USA
Vehicle:
2000 NFR AP1 S2000
'07 Honda FIT sport (5MT)

Default

Quote:
Originally Posted by Uncle Scotty
I put mine under the passengers seat......


...and my idea is to use the 12L tank that goes behind the rear seats to fill a 4-6L tank, using the low pressure pump that comes with the 12L tank, that is in the battery space.....to feed the HP pump.....and maybe something like this....
http://www.autospeed.com/cms/A_0589/article.html

....to control it if I don't use the UTEC....
heh.. that's the labtronic controller I was talking about .

Jorge (RiftsWRX)
www.ProjectWRX.com
RiftsWRX is offline   Reply With Quote
Old 04-06-2005, 07:07 AM   #15
john banks
Scooby Specialist
 
Member#: 11669
Join Date: Oct 2001
Location: UK
Vehicle:
Evo IX 345 WHP

Default

Tacho output from the ECU is usually a 12V square wave. Use a resistor and a diode to shunt it to 5V and stick it into the input capture pin of an AT Mega8 running on a Simmstick ready made PCB (power and ground from the TPS sensor wiring), programmed with free BASCOM AVR. Setup an interrupt on the 16 bit timer 1 with 64 prescaler for input capture, RPM = 3750000/capture1 (if using 8MHz crystal). MAP sensor will go straight into a 10 bit ADC input, on mine manifold absoulute pressure in bar is (MAP input-180)/289. PWM output on Timer 2 8 bit, set the prescaler to get your desired frequency, 15 Hz might be sensible for a water injection solenoid?

Do a 8*8 interpolated map of RPM vs MAP with PWM lookup duty and write an RS232 interface to update it. The PWM output can feed a TIP127 (or similar) PNP power transistor which can run the boost control solenoid anyway.

If you look at some of my posts on here and 22b I've widely published the circuits and code snippets.

I have my MAF based ECU running without a MAF with a similar setup.

I have no professional electronics background and no training in it. It is easy.
john banks is offline   Reply With Quote
Old 04-06-2005, 11:29 AM   #16
ride5000
Scooby Guru
 
Member#: 32792
Join Date: Feb 2003
Chapter/Region: NESIC
Location: lincoln, ri
Vehicle:
2003 GGA MBP
12.9 / 105+

Default

Quote:
Originally Posted by john banks
Tacho output from the ECU is usually a 12V square wave. Use a resistor and a diode to shunt it to 5V and stick it into the input capture pin of an AT Mega8 running on a Simmstick ready made PCB (power and ground from the TPS sensor wiring), programmed with free BASCOM AVR. Setup an interrupt on the 16 bit timer 1 with 64 prescaler for input capture, RPM = 3750000/capture1 (if using 8MHz crystal). MAP sensor will go straight into a 10 bit ADC input, on mine manifold absoulute pressure in bar is (MAP input-180)/289. PWM output on Timer 2 8 bit, set the prescaler to get your desired frequency, 15 Hz might be sensible for a water injection solenoid?

Do a 8*8 interpolated map of RPM vs MAP with PWM lookup duty and write an RS232 interface to update it. The PWM output can feed a TIP127 (or similar) PNP power transistor which can run the boost control solenoid anyway.

If you look at some of my posts on here and 22b I've widely published the circuits and code snippets.

I have my MAF based ECU running without a MAF with a similar setup.

I have no professional electronics background and no training in it. It is easy.
if you run a UTEC, you might want to wait before embarking on that journey... i've heard a few little birdies tell me that the next firmware release will include a WI map which controls the DC of the spare solenoid output.

i didn't hear that DIRECTLY from the horse's mouth, but it was damned close, so take it FWIW.

of course if you want to be a badass DIY-er like jb here you can roll your own! learning a new skill is always cool.

ken
ride5000 is online now   Reply With Quote
Old 04-06-2005, 02:48 PM   #17
RiftsWRX
Scooby Guru
 
Member#: 6124
Join Date: Apr 2001
Chapter/Region: MWSOC
Location: Glendale Hts, IL, USA
Vehicle:
2000 NFR AP1 S2000
'07 Honda FIT sport (5MT)

Default

A little birdie told me it will be for both DBW and non DBW UTEC's. Which means I'm soooo there.

Jorge (RiftsWRX)
www.ProjectWRX.com
RiftsWRX is offline   Reply With Quote
Old 04-06-2005, 03:06 PM   #18
ride5000
Scooby Guru
 
Member#: 32792
Join Date: Feb 2003
Chapter/Region: NESIC
Location: lincoln, ri
Vehicle:
2003 GGA MBP
12.9 / 105+

Default

so that's three birdies now...
ride5000 is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
coolingmist METHANOL/WATER Injection systems Coolingmist Private 'For Sale' Classifieds 0 07-06-2006 08:54 PM
SMC Alcohol/Water Injection system!!!!! 500whp.com Engine/Power/Exhaust 24 01-30-2006 04:47 PM
water injection system pictures installed phamster Water/Methanol Injection, Nitrous & Intercooler Cooling 1 02-22-2005 12:25 PM
WRXTuner Alcohol/water injection system jigga Private 'For Sale' Classifieds 8 07-30-2004 07:07 AM
OH: Alcohol/Water Injection system hawker800mech Private 'For Sale' Classifieds 0 04-13-2004 12:48 PM


All times are GMT -4. The time now is 05:42 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.