Hello,

I need to add H2O/meth injection to my supercharged car as I’m upping the boost. I have a stage-I setup with a Sureflow 150/100 (in a box) and a couple of pretty good, mappable AIC’s (auxiliary injector controllers). I’d like to marry them up into a fine tuned setup… I’ve also got a pretty skinny budget.

From what I’ve gleaned, I need a PMW valve that can talk to my AIC (run at the same frequencies). A valve that does just that exists but it’s really pricy. I’d like to figure an alternative.

Options as I see them:

1) Find a PWM valve that operates at the right AIC frequency (unlikely, Googled for days, haven’t found one yet)

2) Find a proportional valve that can handle the AIC’s high frequency (400+HZ)

3) Find a fuel injector who’s insides won’t dissolve with a 30/70 meth. to H2O mix

4) Concoct a piggyback board (or software tweak) to slow down the pulse frequency of the AIC

5) Amplify the AIC signal to on with enough amps to power and control the Sureflow.

I know its been done in variants of what I have in mind, but for one reason or another they didn’t seem to suit my Ideal.

Any thoughts or ideas are appreciated.


Regards

PK

BTW: I am familiar with Aquamist ($$) Coolingmist ($), & Clippard (?).

 

In order to persuit a PWM/IDC system you need a steady water pressure. How does you Shurflo pump regulate the 100psi line pressure?

Clippard's mouse valve (EV2xxx) is designed to operate between 10-30Hz. Fuel injector frequency is normally between 30-60Hz. Not sure the frequency of your AIC. Important to know this.

Are you sure the AIC output is 400Hz+? If this is true, you need to use Clippard's proportional valve: EVP series.

not easy


Pick the correct valve, you save time with electronic work.

Pump speed is not linearily proportional to flow after restriction (nozzle)

You are going to enjoy this long journey to a successful outcome. Get to know the functions and specifications of each component and matching them correctly is vital to the final outcome.


Clippared valve ranges between $25 to $50 (alll stainless). The opening/closing time is between 4-5ms. Standard Fuel injector responses at ~2ms.

 

PK,

We will be talking to you later in more detail. Our valve has been integrated into several ECUs including Haltech, autotronic and PFC. Cant promise its going to work with your AIC but Here is a review:

https://www.evolutionm.net/forums/sh...d.php?t=320347

Its a versitile valve, It can inject based on an amplified 0-5V as a positional valve, or through PWM on a proportional basis. Vari-Cool uses a frequency higher than 400 HZ, however everyone that has used a 3rd PARTY ECU has used a low frequency around 25 to 30 HZ with great results. Our valve assembly uses EPDM seals so its compatible completely with methanol as well as 430 F stainless. An inline water filter and the best part, it ships with 2 valves. You will be able to flow upto 10 GPH with our valve assembly. Also, we have a device that can keep your pump at a steady 120 PSI that will keep the pump in perfect harmony with S-HSV.

I will talk to you later today when you call.

BTW, I am very interested to see how this works for you. I will talk to you in detail later, but I will make you the offer that you can purchase our S-HSV and pump bypass, if you cant get the valve to work or are un-happy with its performance I will refund the full purchase price (minus the shipping). I do this because I think it will be a worthy test of these fantastic valves and I realize you are in uncharted territory.

David

 

Hello all,

Thanks for your replies. I talked to SplitSecond, the manufacturer of my AIC (1 injector) I plan to use to drive my single PWM valve, to no ones surprise my numbers were based on some wrong assumptions. But equations here might not be right either.

1. My AIC fires a single 12v, varying length pulse for every intake stroke for every cylinder. (3 pulses per revolution)

2. Pulses mapped in the grid are charted in milliseconds.

3. I don’t really own an Evo, (great forums though…)

Check me on my arithmetic here;

@ 700 RPM ((6 cylinder/2 stroke cycles)*700 rpms)/60 sec. per min =35 pulses per sec. =35HZ
@ 2500 RPM ((6/2)*2500)/60=125HZ
@ 5500 RPM (3*5500)/60=275HZ
@ 7000 RPM 21000/60=350HZ


700 rpm idle, 2500rpm’s about the lowest I can see a boost…goes by pretty fast, 5500 is about peak torque, & 7000 is the red-line.

So It looks like I need a PWM valve capable of running from 125HZ to 350HZ. However, someone doing a similar thing with his own equation came up with much much smaller numbers (for his car).

Ideas? am I off?

Regards, Peter



BTW; The pulse timing is calculated from vac/pres sensor and tach signal.

 

I am afraid the AIC output is not going to be good for any valve. Based on your calculation.

There isn't such a valve that will do as you stated.

 

Really, It did seem that my numbers fell into a sort of gray area. 2 fast for one valve and to slow for another. The weird thing is I know a couple of people that have done it …with your valves, albeit on Miatas, but two cylinders shouldn’t make that big of a dif.

Do my calculations look tight?

Regards,

PK

Oh yeah: I did find a guy runing alky/h20 through plain old injectors...with some sort of ani corrosion inhibitor/

 

Rather trying to struggle with the frequency range, convert the variable frequency/PWM to fix frequency/PWM.

Consider a clippard valve takes 4mS to open and 4mS seconds to close.

Based on your calculated figures:
At 35Hz, you have a pulse width of 28mS. Taking 8mS away, you will get 20ms of control range. 20mS/28mS= 71%
At 350Hz, you have a pulse width of 2.8mS! The pulse width is not wide enough for any control.

People tends to do many things without paying too much details on the mechanical electrical constraints. I would not start you project this way. Fuel injectors has an opening/closing time of ~2ms.

And ... do not pay too much attention of marketing hypes - a Hyper high speed valve (HHSV) or Super-HHSV means nothing. We have a valve that can respond to 0.8mS open/shut period but it is too expensive and over-rated for this type of applications.

 

[QUOTE=Richard L;5202685] Rather trying to struggle with the frequency range, convert the variable frequency/PWM to fix frequency/PWM....At 350Hz, you have a pulse width of 2.8mS! The pulse width is not wide enough for any control.... Fuel injectors has an opening/closing time of ~2ms.

HA! Do you think we'd be having this converstion if I fell for every new spot cleaner that came along with the word "super" in it? L.O.L.
Richard

Ya I’m pretty conflicted. I had contemplated going analogue from my PWM signal but that seemed I’d probably not be not much better of than a stage II with a controller. Also means I’ve got $500 worth of reasonably sophistication (AIC’s) I won’t use and can’t easily sell.


Couple of things , just thinking aloud, If a fuel injector has a reaction time of 2 ms, why not just use one? I recognize concerns would be corrosion and the narrow pray pattern an unknown comparative atomization quality.

But if atomization is the issue, how about using a fuel injector as just an inline PWM valve and retain the normal nozzle. Not sure how well it would do because redundancy in nozzle restrictions.

For corrosion, as your PIX show, a little Clippard of (nickel plated brass I guess) shows no sign of corrosion with a h20/meth mix. A new online pal of mine uses “Klotz Uplon oil” mixed with his alky mix and has had no problem with his fuel injectors.

All I need now is to sort this valve biz. (A nice 1.5 gal. spun aluminum h20/meth tank would be nice to)

Regards,


Peter


Oh yeah, just picked an SMT6 AIC which will be a vast improvement from what I currently have (for fuel/timing, etc). Has and in/out 5-10v analogue mapping to, but it's low on amps. Think it's for playing tricks on your ECU.

 

To putting things into the right prospective, asking an line valve to cope with firing three pulses per revolution is beyond present technology.

Lets take this a bit further. If your engine is a four-stroke typr, then it will only have one intake stroke per revolution. It may be my mistake not reading your early post more accurately.

If this is the case, this will significantly reduce the demand on the performance of the inline valve. Unfornatrly, it still fall short of a decent control range.

It is possible to use low impedance fuel injectors, response time of ~0.8mS, but you need to have a "peak and Hold" driver. I don't believe your AIC is of this type.

Using a fuel injector as an inline valve will work, just need to put a matching atomisation nozzle in front.

Mis-matching is a common problem in this industry, sometimes you can find a way around it but sometimes you just hit you head against a wall. I think you are experiencing both.

I can make you a 0-5V to 0-100% fixed frequency PWM converter if you are so hard pushed to make this project a reality. You can have 20Hz or 50Hz.

 

I noticed you don’t drive an Evo either. I worked for a guy once who had a 70‘s something Citroen SM, loved the way it “levitated” up off the ground when started.

To be honest I haunt these forums because mods to Porsches are only really done with checkbook in manicured hands. Mine are done with old wrenches in dirty gloves. Anyway, valve, Must be a way to make it fly.


For clarification, my car fires 3 time per rev (I think, one AIC said set it up as a 3 cyl. 2 stroke…). The new AIC has a mapped analogue output of 1-10v. with a +/-5v. swing (I.E. 4-9v, 3-8v, 1-5v, etc) as best I can tell.

I'm not sure what my AIC puts out either, peak and hold wise.

I’m bit perplexed in that there seems to be a pretty wide gap between one nozzle size to the next. Doesn’t seem conducive to real fine tuning.

As to your mention of a 0-5v fixed frequency controller at 20-50HZ. How would that work? give it a blast of H2O every 7 or 8 revs.? Or just make a continues stream at some points and be a bit lean at other times?

As for being _ell bent on doing it this way, dunno, got these spare AIC’s that are more sophisticated that anything I’ve seen for W/I. I know people who have done it on 4 bangers. Gotta be something to make one work.

Thanx & Regards. PK

 

So A new wrinkle; I Picked up a better AIC which is no better or worse than anything else (except my current installed)one. I does however have a 3rd channel of a mappable 0-5v analogue output. I wonder what it would take to bring it up to 12 volts and the amps required to run a decent proportional valve.

Regards, PK