maximum flow for 0.4 mm, 0.5 mm, and 0.6 mm Aquamist nozzles

[mushin]

This is for my supercharged Focus (big boost Jackson Racing Eaton/roots style supercharger running 14 psi of boost). I'm not sure which nozzle will be best to start with, and I want to know what the maximum flow rate is for those three sizes. The 1s kit comes with the 0.5 mm nozzle, if I'm not mistaken, but I wonder if this will be too much for a Focus that is (before injection) making about 180 whp. Should I start with the 0.4 mm nozzle?

[Richard L]

I think the 0.5mm jet is a good start. I based the WI rate by your power output of 180whp. Not sure what that would translate it flywheel HP - I guess it will be around 220-230HP?

You will require approximately 500-600cc/min of fuel per 100BHP. if you are injecting 1.1 litre of fuel /min then one 0.5mm jet will equate to about 20% of water to fuel ratio.

We normally recommend between 10-15% but due to your lack of intercooler and making boost on top of the standard compression ratio(?). I think 20% is about right.

Please post your results when possible.

[JohnA]

Richard,

Another relevant question I think:
Is there any rule-of-thumb regarding the activating boost-pressure for the WI?

[mushin]

Thank you, Richard. On the Focus, 180 whp works out to probably around 210 flywheel hp. Does this change your assessment any? Thank you for the information!

[Richard L]

No, 0.5mm jet is fine, roots type supercharge tends to have higher discharge temperature than the centrifugal type, the 0.5mm jet shoudl work well.

[Richard L]

John,

Rule of thumb for the onset of water injection for normal unmodified factory car should be just nelow the factory boost pressure.

10% of water will normally allow 1 compression ratio increase or arounf 3.7psi. Other factory such as ambient temperatures and fuel grade woudl affect the quoted figure.

[Richard L]

Mushin,

Does the Jackson Focus kit come standard with 14psi?

[JohnA]

John,

Rule of thumb for the onset of water injection for normal unmodified factory car should be just nelow the factory boost pressure.

10% of water will normally allow 1 compression ratio increase or arounf 3.7psi. Other factory such as ambient temperatures and fuel grade woudl affect the quoted figure.
That's roughly what I thought.
Cheers Richard, I'll add this info on my website if you don't mind 8)

[mushin]

Mushin,

Does the Jackson Focus kit vcoem standard with 14psi?

Richard,

No, it comes stock with 5 psi, at best. I have a larger crank pulley and smaller supercharger pulley, 42 lb. fuel injectors, and custom tuning.

[Richard L]

Mushin,

Unless you have your compression ratio decreased, you need to run at least a 0.7 or 0.8mm jet - no intercooler assumed.

[mushin]

Mushin,

Unless you have your compression ratio decreased, you need to run at least a 0.7 or 0.8mm jet - no intercooler assumed.

Wow! Why is that? I didn't order any that big!

[Jason96SL2]

You're suffering from major inefficiency. Sounds like things are getting too hot for making good power. I would bet you could throw down 250hp with some dyno time and water. Intercoolers are cool too. I have one for my eaton.

[mushin]

You're suffering from major inefficiency. Sounds like things are getting too hot for making good power. I would bet you could throw down 250hp with some dyno time and water. Intercoolers are cool too. I have one for my eaton.

That is definitely true. Coolant temp hits 250 degrees under WOT and high boost. I just thought that 0.7 to 0.8 mm would be too much for my application, but I guess not! I'm in the process of ordering 0.7, 0.8, and 0.9 mm nozzles from BKA Inc. here in the U.S.

[Jason96SL2]

Lemme know how it goes...I've been too scared to slap on the 14psi pulley on my M90 and I have an intercooler. :oops: Those eatons make some crazy heat at higher boost pressures.

[mushin]

Lemme know how it goes...I've been too scared to slap on the 14psi pulley on my M90 and I have an intercooler. :oops: Those eatons make some crazy heat at higher boost pressures.

Sure will. I can't wait to take it back to Alternative Auto Performance for retuning once the kit is installed.

[cmetzner]

Richard -

I would like your feedback to see if I understand this correctly. I have an M62 sc on my 99 Miata. I have no intercooler, fueling is controlled by the Jackson powercard to run at 12.8 - 13.3 under boost. The sc boost is 6.5 psi with the pulley I have.

I use a .4mm nozzle on my 2d system. From the Aquamist site, I calculated that this would cool the air charge by about 80*F.

Mushin, it seems impossible/unlikely that you can get the cooling you need by WI alone! When I used larger nozzles to flow more water, the car balked off the line. And I am running much less boost than you.

Running that amount of boost you would want to inject more water but, Richard, isn't there a point where the amount of water needed would begin to drown out the combustion?

[robbilau]

Hey Chuck,

I've got an FMI crossover tube on order and I'm going to see how far I can go without an IC. I can meter the water in more ways than the 2d so I should be able to find close to the max cooling. The piping and jets etc will be in in a couple of weeks I think.

Anyway, if I remember we hooked your WI signal to a piggy injector, not so? Did you upgrade to the powercard since then? It seems odd you would bog with a 0.4mm jet as you shouldn't really have much until higher rpm.

[cmetzner]

Hi Robbie -

I upgraded to the jackson powercard. That meant that I had to unhook the piggy injectors.. That meant that I had to tap the water injection into the stock fuel injectors.

The car does not bog down with the .4mm jet, it was bogging down when I was using the .8 or .9 jet.

I was advised by turboice or the forum admin on this site (can't remember which) that my water % should be about 3% - 8% of fuel. He said this because I am not replacing fuel with water. My fuel is set by the powercard at 12.8 - 13.3 under boost. I cannot change the map in the powercard.

He said (whoever "he" was) that because I was using the WI as an intercooler only and not leaning the fuel as I was adding water that I should be at 3 - 8 % water.

I was also advised by another that I should begin injecting at about 2psi. The car runs best injecting at 2psi; with a .4 or .5 jet and stock heat range plug.

I will be interested to hear your results. I have no way of measuring the air temp. I am first going to spend the money on a new clutch before the gauges.

This summer I will probably change the pulley on the sc to get to 9psi. The powercard handles fueling to 8psi. So, I will have to hook up at least one piggy injector. I have heard of people running 6 cyl cars to 10psi on water alone with good results.

[robbilau]

That sounds reasonable. But I don't think you are running rich enough at 12.8 - 13.3 to restrict yourself to just using the 3-8%. That's right around the correct AF for max power on gasoline. Some of the stock import turbos run very rich under boost - up to 10:1 - to cool combustion. That's really the case where you need to lean up the fuel for power as you add water for knock suppression. You can generally run up to 25% water compared to fuel depending of course on the heat of the air etc.

So I think you could run up to the .5mm or .6mm jet. Let's see, the stock injectors are about 270cc/min. With the .6mm jet you have 250cc/min which is 23% of fuel flow which is about as high as you want to go. So your 0.4mm jet is probably quite well suited at about 15%. You might switch up to progressively bigger jets up to .6 as the summer heat grows if you find they help.

In terms of what can probably be run on water I had a tech from MoTeC help get my car baseline tuned. He typically tunes drag cars and is well known in those circles. While getting boost control sorted we hit over 15psi by mistake (fun mistake, I must say) and he remarked out of the blue that I could probably run 15psi on 91 octane with water injection.

[cmetzner]

Thanks for the info. From what I gather from different sources, I can use the water only instead of an A/W intercooler at the modest boost that I plan to run.

My plan was to use a larger jet in summer. BR Performance is also selling a heat shield for the header. The sc sits right on top of the unshielded header.

When you run 25% water do your plugs show any signs of fouling? Do you use the stock heat range plug?

I think my car balked because I was using the 8mm jet and a spark plug that was one level cooler than stock. Even NGK says one heat range cooler for every 75 -100 hp added. I am right on the edge having added 65 - 75 hp.

[robbilau]

I only run about 12% water max as I have an intercooler already, so I am not sure what my car would do at 25%. No sign of foulling at those levels on plugs 1 heat range cooler.

I'm looking forward to the water experiments. All the physics say I should be able to get down to 65F at full boost with just water. We'll see...

[mx5]

Btw, you guys with NB Miatas, when calculating the percentage of water you're running, do you correct your calculations for the different fuel system you're running? I mean i.e. 240 cc/min fuel injector flows 240cc/min in NA Miata, but not in NB one

[robbilau]

No, I have 550cc injectors and look at my actual logged duty cycle. I have to say a good aftermarket ECU makes projects like this SO much easier!

[mx5]

You have 550 cc injectors but these flow 550cc/min in NA and not in NB. Let me calculate ~ how much they flow in NB car. This has nothing to do with what ECU you're running. The ECU controls how long the injectors are open, and not how much fuel they flow for that time

P.S. Robbi, Julian here btw

[mx5]

550cc/min injectors should be around 650cc/min in a NB Miata

[cmetzner]

So what is the flow from the stock injectors in an NB?

Brant told me that the flow is 235cc/min and the powercard pushes the injectors as high as 95% capacity during boost.

[robbilau]

Hey, Julian!

Strewth! I just checked my shop manual and you're right - the NB runs from 90psi peak to 50psi hold. I was thinking 43 psi all this time.

What numbers are you using?

[robbilau]

The shop manual injector test section says from 66-82cc/15s which is 264-328cc/min FWIW. They do not specify the fuel pressure for the test, though, just that the stock pump is used.

[mx5]

I've heard the NB run at 60 psi (and that's what I used) but I've never had one or seen a friends car with fuel pressure gauge installed - so I am just guessing.

The NA Miatas run around 43 psi fuel pressure stock (IIRC 40-46).


So the formula is injector_actual_fuel_flow = sqrt( actual_fuel_pressure / injector_rated_fuel_pressure) * injector_rated_fuel_flow

RC Engineering rate their injectors at 43 psi (probably like most of the other manifacturers)

[mx5]

So what is the flow from the stock injectors in an NB?

Brant told me that the flow is 235cc/min and the powercard pushes the injectors as high as 95% capacity during boost.

The NA8 (like mine) has these same size injectors and flows that much what you say. These same injectors flow more in NB because your fuel pressure is not standard. I've never done experiments with NB cars. Just install fuel pressure gauge in yours and then calculate what you get :)

[bloit]

The figures that you are quoting for water flow seem very interesting. Currently there aren't many people in australia running superchargers let alone water injection. I have an eaton m90, no intercooler (looking at making water to air) on a 2L fiat/lancia engine averaging 21psi of boost. I have had it out to 26psi. No currently i am getting huge inlet temperatures and having to retard timming to reduce detonation.

I have the water injection system running of the waste gate settings on a haltech e6k which means that i can map water flow against rpm while i am under boost. This helps in that i can run more water top end.

What sort of flow rate of water should i look at trying to use. At the moment i am still yet to feel the car bog down and haven't noticed any change in inlet temperatures as i add more water..

[cmetzner]

Btw, you guys with NB Miatas, when calculating the percentage of water you're running, do you correct your calculations for the different fuel system you're running? I mean i.e. 240 cc/min fuel injector flows 240cc/min in NA Miata, but not in NB one

I was directed to a long thread at miata.net that discussed the different flow rates between the NA and the NB miatas. I did correct for it. From what I recall, I think Robbie is right. The stock injectors flow 270cc/min on the NB miatas; 240cc/min on the NA's.

When I refigured, I switched to the .5mm water jet. Car runs fine.

I have to take out about 2* from the stock timing with water; about 4* without water. This is on 91 octane.

[mushin]

I've been running the kit now with the 0.8 mm nozzle for about 1.5 weeks. It runs fine. I'm taking it in for retuning on Wednesday, March 24. Strangely, since the kit was installed, my gas mileage seems to have dropped by 2 mpg or so. I wouldn't have thought it was have affected it until the car was retuned, and then I was expecting a slight improvement, since the car will likely the AFR will be inreased slightly when the injection is occurring. I'll post another update once the tuning and dyno testing is done.

[mushin]

The retune was done today. It looks like I gained 10 fwhp from my new 4-2-1 header, and another 20 fwhp from the retune with the injection system. I'm now at 202 hp and 194 lb-ft. of torque at the front wheels. Although I'm totally happy with this, and the car is quite quick now, the tuner was very cautious about timing advance increases. He raised the AFR from about 11 to 12-12.5, which the car liked a lot, but he only raised the WOT/high RPM (high boost) timing by 1 degree to 16.5. He wanted to play it safe. I have no problem with this, but I am curious if we could have bumped the timing advance up more. Either way, the car is a blast to drive!

Thanks to everyone who helped! Oh, and my previous post comment about the drop in gas mileage seems to have been a fluke. I think it stayed about the same after the kit was installed. With a higher AFR now, I would expect slightly better mileage now, perhaps.

[Charged Performance]

Unless the results are painfully obviously wrong - I generally wouldn't expect anyone to question a tuner's decision in the tune.

Was the tuner using det cans? I mean if he was monitoring detonation and wasn't hearing any and you were both happy with the fuel level try the timing at another .5 degree in steps and see if the torque curve lifts up. If he is starting to hear det or there is not an appreciable pick up on the torque curve, drop it back to the last setting and you are probably where you need to be.

Baby steps - if the tuner hasn't used water injection quite a bit - he has every right to be cautious within his comfort level. It hurts his reputation a lot more if your engine blows than it helps if he got you another 5-8 hp. If the engine is running strong and you bring it back and he does a leak down test and sees that all is good, maybe you can get him to advance it a bit more.

[titan]

i have a jackson racing supercharger on my zts focus,so i guess this question/s is for focus owners with chargers but input form anyone with a turbo/supercharger would be greatly appreciated.

What kind of charger do you have?
How much boost are you running?
How did you achive higher boost without distroying the charger?
What are the limits of the charger?
Can you inject befor the blower?
What kind of horsepower/torque increas did you get?
What do you think i should do to my focus?

I already have Eiback suspension,ford racing shorty headers,off road pipe,roots type 5psi blower,magna flow cat back,

[mushin]

i have a jackson racing supercharger on my zts focus,so i guess this question/s is for focus owners with chargers but input form anyone with a turbo/supercharger would be greatly appreciated.

What kind of charger do you have?
How much boost are you running?
How did you achive higher boost without distroying the charger?
What are the limits of the charger?
Can you inject befor the blower?
What kind of horsepower/torque increas did you get?
What do you think i should do to my focus?

I already have Eiback suspension,ford racing shorty headers,off road pipe,roots type 5psi blower,magna flow cat back,

Go to http://www.focaljet.com. Do a search on the "Forced Induction and Nitrous" forum, and you'll get all sorts of info. However, here's a rundown of mine:

I have a JRSC on my 2001 Focus ZX3.

I'm running a maximum of about 14 psi.

The M45 Eaton roots blower won't be destroyed at this increased rotational speed, but it does go beyond it's designed efficiency (i.e., it runs very hot and is very inefficient). I have a 5.9" crank pulley (stock is 5.17") and a 2.3" supercharger pulley. I did not intend to go to 14 psi with this setup--I was expecting closer to 10 psi. If I were to do this again, I would go with a smaller crank pulley--probably a 5.5", but no more than a 5.7". I got my pulleys from ASP Racing, but others make them.

From what I've seen about this blower, injecting before the blower is good for better distribution of water to the cylinders, but it's not so good for the low friction coating on the supercharger internals.

I'm not sure which increase you're looking for. Stock JRSC (with stock pulley and "tuning") is good for about 150 whp and a little less torque. Without the water injection, but with custom tuning, I got 172 whp. A FocusSport 4-2-1 header added 10 whp to that. Tuning for the water injection added another 20 whp (with conservative timing increase, and increase in A/F from 11-11.5 to 12.5). I'm now at a little over 200 whp and 194 lb-ft. of torque.

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