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  #21  
Old 04-05-2016, 02:14 PM
parmas parmas is offline
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Default Re: Nozzle spray angle...

Quote:
Originally Posted by jondee86 View Post
Hahahahahah... just had a look at what a port injection system costs
So an end to thinking out loud. It is always possible to upgrade, so for now
I will go with a basic two nozzle system... one pre-charger and one post-
charger. Standard nozzles installed at 45 deg in the bends as per the above
sketch.

From what I understand, placing the post charger nozzle further from the
inlet manifold would help the cooling effect, but increase the chances of
water being centrifuged out of the airstream. Placing it in the last bend will
reduce the time for cooling, but allow more water into the cylinders in
droplet form... so perhaps the better option ?

The more the consistency of the injection the less variables you will get. Droplets are only good for cooling the charge while injection is stopped or throttle is closed. The cooling effect is so drastically seen since engine is at no load/off boost (decelaration) and heat is not generated while water is still evaporating into the piping. How much? From 40-15DegC in seconds easily.

As in regards to positioning of the nozzles, I already gave my one cent.


The pre-charger nozzle appears to be less critical as the charger "mixes"
the air and will not be sensitive to droplet distribution at the inlet.

The only question remaining is whether it is necessary to use one (or two)
checkvalve nozzles ? There will be some pressure differential between the
nozzles, so draining could occur during out of boost driving. However, there
will only be about 0.5 metres of 4 mm tube between the nozzles, and this
should not create any significant delay between activation and spray ?

Again, as already explained before if your charger matches your engine and working into it's efficiency eliminate the pre-charger nozzle. Regarding nozzles, I like built in checkvalve nozzles but that is your choice.

EDIT: Oh,and one last question... what would be the recommended water
split be between the pre and post charger nozzles ? 25/75 ?

Trials is your best answer. I would begin with water only to eliminate excess fueling and AFR changes. After that trial, report back to us and we will try to help you in the best way possible

Appreciate the input as I like to examine the alternatives

Cheers... jondee86
Jondee, refrain from asking more questions, you have a good thread to refer on. Read it out slowly and decide from where to begin.

Good Luck!
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  #22  
Old 04-05-2016, 02:51 PM
rotrex rotrex is offline
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Default Re: Nozzle spray angle...

Port injection costs three extra jets, that is all.
You can get 4 jets with integrated check valves form aquamist and combine them with any feed of pressurized mix you like.
To test the post supercharger jet, just get a extra jet for this and as parmas said, try it out.

My system is a former Auqamist 2c. After I had pump issues, I installed a Flotec 160PSI pump and slightly modified the aquamist loom to maintain functionality, .ie. Blue LED and system off if tank is empty and to maintain the pump runs indicator.
I kept the constant presure supply and the Aquamist fast acting valve controlled by the ECU. The valve does not care what jets I mount. :-) As long as the pump is up to it, it works, The pump itself runs to its preset pressure and stops. Should the railö pressure drop due to injection, it automatically starts again. It also triggers a LED in my cockpit. The faster it flickers, the more I inject. :-)

With water you will lose power unless you advance the ignition timing. The more you drop power, the more water enters the cylinder in the form of mist.

Regarding jets, I'd purchase a selection. For the port injection, I am on 4x 0.4mm C aquamist jets and have the feeling I could even go to 4x 0.5mm. Literally, the more I inject, the more power I can extract after a ignition adjustment.


If your ECU has a adaptive fueling option, just give it your desired target AFR and let it sort the fueling with the extra alcohol injected.

If you start with water, you'll find the engine will sound soft. This is a indication of the slower and delayed burn.

In terms of space, you need some 3cm above the plenum for the jet, a piece of 4mm tubing and a 90 deg bend.

Other manufacturers may have flatter jets or some that are mounted to a 90 deg bend.
I have good experience with the Aquamist jets. You can maintain them as they are screwed together from two pieces, never had once blocked up, contain a filter fritt. Always use a pre filter. No component of any WI system likes any dirt or mineral deposits. Always use deionized water. If it's marked for drinking, it is no good as RO purified water for drinking purposes has minerals added for tast and health.

Last edited by rotrex; 04-05-2016 at 11:33 PM.
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  #23  
Old 05-05-2016, 08:54 AM
jondee86 jondee86 is offline
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Thumbs up Re: Nozzle spray angle...

Thank you gentlemen There is a lot to learn and some experimentation
will be required to gain more understanding. I shall start with a single nozzle
and add a second once I have the system installed and working for long
enough to get the basic tuning completed.

I shall also be using different pulleys so that I can start with 10psi boost,
move to 15psi, and then finally to 20psi if the results indicate that 20psi can
be reached with my setup. Adding port injection will be something to consider
when I change to the 15psi pulley.

It will be several months before the conversion from NA to supercharged is
completed, but you can be sure I will report back once I have the car tuned
and the WI system working.

Cheers... jondee86
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  #24  
Old 05-05-2016, 11:13 AM
rotrex rotrex is offline
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Default Re: Nozzle spray angle...

15 and especially 20 PSI are some serious boost numbers to push through a roots style blower without charge cooling and on petrol.
As Parmas and others did you will indeed need a large amount of ADI fluid to keeps this from having knock issues.
I also suggest in this case to consider pre compressor injection as suggested ans successfully employed by Parmas. Thing will get really hot.
Have you checked your compressor map regarding the expected flow and boost numbers?
Are you still reasonably efficient?
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  #25  
Old 05-05-2016, 12:28 PM
jondee86 jondee86 is offline
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Exclamation Re: Nozzle spray angle...

Ahh... good questions, and I don't have any good answers

When I began this project I was only intending to target 15psi, but the
only pulley I could get at the time was a small one that was 20psi capable.
I did look at A2W intercoolers, but decided to see what was possible with
WI because it was easier to implement. These are the maps I was given...

Isentropic Efficiency


Volumetric Efficiency


I don't really fully understand how to interpret them. Hopefully, being a
modern twinscrew design, WI will be able to control the heat generation
up to some reasonable pressure. I am not obsessed with reaching 20psi
and will be quite happy if I can run thru the gears at 15psi now and then
The supercharger I am using has an internal pressure ratio of 1.4 and my
engine has a compression ratio of 8.9:1 if that helps ?

Cheers... jondee86
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  #26  
Old 05-05-2016, 05:32 PM
rotrex rotrex is offline
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Default Re: Nozzle spray angle...

What's the HP target? This SC seems good for some 300HP, so about 250g/sec of air, for a pressure ratio of 2, so a tad less than 1 bar of boost. This suits to a engine with NA power of about 150HP.

The first diagram shows the efficiency over airflow and pressure ratio. You need about 100g of air per second for 120HP. The lower the efficiency the hotter the air gets out of the SC. The second map shows what percentage of the theoretical volume of the SC is expelled per revolution. Say it pumps 1liter per revolution and vol efficiency is 89%, you only get 890ml of air out per revolution. Pressure ratio is the ratio of output pressure and input pressure, both on the absolute scale. So athmospheric, 1bar absolute, in and 2 bar absolute or 1bar of boost out is 2/1=2. There always intake losses, so your real PR is always a tad lower (10-15%) than the ideal number.

Last edited by rotrex; 05-05-2016 at 05:40 PM.
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  #27  
Old 05-05-2016, 05:57 PM
parmas parmas is offline
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Location: malta
Posts: 210
Default Re: Nozzle spray angle...

Quote:
Originally Posted by jondee86 View Post
Ahh... good questions, and I don't have any good answers

When I began this project I was only intending to target 15psi, but the
only pulley I could get at the time was a small one that was 20psi capable.
I did look at A2W intercoolers, but decided to see what was possible with
WI because it was easier to implement. These are the maps I was given...

Isentropic Efficiency


Volumetric Efficiency


I don't really fully understand how to interpret them. Hopefully, being a
modern twinscrew design, WI will be able to control the heat generation
up to some reasonable pressure. I am not obsessed with reaching 20psi
and will be quite happy if I can run thru the gears at 15psi now and then
The supercharger I am using has an internal pressure ratio of 1.4 and my
engine has a compression ratio of 8.9:1 if that helps ?

Cheers... jondee86
I am sorry to tell you this but you better leave that 20psi pulley on the shelf.

I am attaching you the best and max high boost efficiency.

The First line shows where the charger is meant to work best which is 7-8psi @ 90g/sec or 12lbs/min. To make it more simple : With my 1.5L engine and a GT2560 turbo, I reach 12lbs/min @ about 3000rpm.

The Second line shows where the charger peak it's efficiency or in poor words begins to "overheat" the Air drasticaly compared to relatively lower pressures.
The Max working pressure is 15psi @ 170g/sec or 22.5lbs/min. To make it more simple : Compared with mine I reach 22.5lbs/min @ 5500rpm

If I knew your engine specs I could understand where this charger is with your engine. Specs needed:

- Engine size cc
- No of cylinders
- No of valves

To simply understand boost efficiency if you make a chart of boost vs air temperature you will understand without any compressor maps where your charger efficiency is. The chart will show elevated/abnormal air temperatures when out of efficiency.

Example :

Air Temp marking 30DegC at 5psi @ 3000rpm and 31DegC at 8psi @ 4000rpm.

DIFF 3PSI = 1DegC increase

Air Temp marking 34DegC at 8psi @ 3000rpm and 40DegC at 11psi @ 4000rpm.

DIFF 3PSI = 6DegC increase

A super efficient compressor would increase Air Temp equally related to boost differential at same RPM. Sadly no compressor is so super at high boost levels ...
Attached Images
File Type: jpg S5-210%201_4PR%20isen%20map%2002s_zps4rxgwfe2.jpg (40.4 KB, 6 views)
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  #28  
Old 05-05-2016, 09:27 PM
rotrex rotrex is offline
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Default Re: Nozzle spray angle...

At a pressure ratio of 2 efficiency mostly stays around 70% even at well over 200g/sec. That is OK.
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  #29  
Old 05-05-2016, 11:29 PM
jondee86 jondee86 is offline
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Posts: 78
Lightbulb Re: Nozzle spray angle...

I'll have to read that a few more times to see if I can understand !!

My engine is 1600cc 4 cylinder 16 valves twincam Toyota 4AGE 8.9:1 comp.
The Sprintex displaces 0.94 litres/revolution with internal PR of 1.4

I don't have a chart for the Sprintex but here is the chart for an Opcon
twinscrew displacing 1.2 l/rev and internal PR of 1.35. Being of similar design
the performance should be similar ?
http://i984.photobucket.com/albums/a...ps49d06897.jpg

And here are typical performance curves for the Opcon Autorotor...
http://i984.photobucket.com/albums/a...psp7gt9r6q.jpg

To begin I will have the 10psi pulley and if it is possible to make 10psi with
WI only, I will be happy with that If I need to have more I will look to add
A2W using a kit like this...



Cheers... jondee86
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  #30  
Old 06-05-2016, 05:04 AM
parmas parmas is offline
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Location: malta
Posts: 210
Default Re: Nozzle spray angle...

Our specs are similar my engine is 1500cc 4cyl 16valve twincam with 8.5:1 compression.

Forget the charge cooler... You definitely not needing it till 20psi
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