Aquamist HFS-5 system: Official Q&A...
#574
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It was refering to my asking if you had a formula for V to CC for the flow sensor.
You mentioned that you would after future testing. I am doing some more logging with the meth kit and I just wanted to see if you had a formula.
I have been using CC = (V - 0.45) *265 which is what KevinD mentioned a while back and it has worked fine for me so far but I was wondering if there was something possibly more accurate.
Sure I could test it myself, but I'm lazy and I wanted to see if you had already done it.
#575
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I'm working on a way to correctly datalog your cc flow. There are a few factors that need to be done. First, to see what your car flows with the engine on (so pump voltage is up) remove the nozzle(s) and place them in a 'covered' 1000ml measuring cup. You can find these at home depot or anywhere that sells fiberglass like boat stores for about a buck.
The next two things you need to do is to manually activate the system but also have the IDC of the HSV (if you have one) be wide open at 100% so you can find its maximum flow limit. Be sure to run whatever mixture you intend to run because meth and water have different specific gravities so they will flow different volumes of fuel per minute. Run the setup for exactly one minute and measure how much it'd flowed.
Now....this is your flow at 0psi of backpressure and 125psi of pump pressure. As the boost increases the volume of flow decreases. So if you are running 28psi of boost, your kit is effectively flowing 125psi of pump ressure - 28psi of boost= 97psi. So its the same as if your pump was running 97psi with 0psi of boost (same as spraying it into the 1000ml container). So to effectively datalog your flow you need the formula to factor in the actual boost pressure, the injector duty cycle (for HSV setups) and the maxumum flow you recorded in the 1000ml container.
The problem with the flow sensor is its scaled. The user adjusts its maxumum flow reading (in volts) so its anywhere from 2-4 volts roughly. I believe setting the gauge so it lights up 5 out of the 8 bars is roughly 3.0 volts. What you need to find out is how much ACTUAL flow you have when the sensor is reading this 3.0 volts.
This is of course at a duty cycle of 100%.
The next two things you need to do is to manually activate the system but also have the IDC of the HSV (if you have one) be wide open at 100% so you can find its maximum flow limit. Be sure to run whatever mixture you intend to run because meth and water have different specific gravities so they will flow different volumes of fuel per minute. Run the setup for exactly one minute and measure how much it'd flowed.
Now....this is your flow at 0psi of backpressure and 125psi of pump pressure. As the boost increases the volume of flow decreases. So if you are running 28psi of boost, your kit is effectively flowing 125psi of pump ressure - 28psi of boost= 97psi. So its the same as if your pump was running 97psi with 0psi of boost (same as spraying it into the 1000ml container). So to effectively datalog your flow you need the formula to factor in the actual boost pressure, the injector duty cycle (for HSV setups) and the maxumum flow you recorded in the 1000ml container.
The problem with the flow sensor is its scaled. The user adjusts its maxumum flow reading (in volts) so its anywhere from 2-4 volts roughly. I believe setting the gauge so it lights up 5 out of the 8 bars is roughly 3.0 volts. What you need to find out is how much ACTUAL flow you have when the sensor is reading this 3.0 volts.
This is of course at a duty cycle of 100%.
Last edited by Jack_of_Trades; Sep 26, 2008 at 05:15 PM.
#576
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I already have a way to turn the kit on 100% duty cycle using a button I wired in for testing purposes. I think weighing the liquid sprayed is more accurate since water weighs 1g per cc and I have a scale that can measure 1 gram differences.
Also the psi of boost that I am running should not matter for the pruposes of measuring volt to cc. Under boost the flow will be less, of course I agree with that, but the flow sensor will measure less. If I find a conversion from v to cc with no boost it will be the same conversion factor with or without boost
good point about the scaling adjustment though I had forgot about that
Also the psi of boost that I am running should not matter for the pruposes of measuring volt to cc. Under boost the flow will be less, of course I agree with that, but the flow sensor will measure less. If I find a conversion from v to cc with no boost it will be the same conversion factor with or without boost
good point about the scaling adjustment though I had forgot about that
#577
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Weighing it works fine if you use ONLY straight water but if you use a mixture of water and meth you would need to calculate the difference in weight for your mixture.
Specific gravities:
Water = 1.00
Methanol = 0.789
Ethanol = 0.787
Denatured Alcohol = .788
50/50 water/meth = .8935
50/50 water/den. alcohol = .894
Most people don't have the comfort of an accurate digital scale (I do since we measure our cooking ingredients with one....my finacee is a personal trainer and shes nuts about that stuff,lol) so the container is "close enough" in my opinion but it definitely is most accurate to weigh it.
I suppose you're right about the voltage being scaled correctly via the boost pressure but I'd like to test it to confirm that its accurate in the "real world". If you know it rests at .5 volts and stays at .5 volts until the flow exceeds 100cc/min (I think thats its rating?) than you can scale the voltage vs. flow.
Specific gravities:
Water = 1.00
Methanol = 0.789
Ethanol = 0.787
Denatured Alcohol = .788
50/50 water/meth = .8935
50/50 water/den. alcohol = .894
Most people don't have the comfort of an accurate digital scale (I do since we measure our cooking ingredients with one....my finacee is a personal trainer and shes nuts about that stuff,lol) so the container is "close enough" in my opinion but it definitely is most accurate to weigh it.
I suppose you're right about the voltage being scaled correctly via the boost pressure but I'd like to test it to confirm that its accurate in the "real world". If you know it rests at .5 volts and stays at .5 volts until the flow exceeds 100cc/min (I think thats its rating?) than you can scale the voltage vs. flow.
#580
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The flow sensor is being constantly improved in terms of software and hardware. The aim is to have a user scalable sensor that will respond accurately from a small flow of 50cc/min to 2000cc/min.
Have an user scaleable output is a luxury compaired to dealing raw pulses from the Hall effect sensor. If anyone wants to experience with a raw signal, I am happy to make that possible.
Have an user scaleable output is a luxury compaired to dealing raw pulses from the Hall effect sensor. If anyone wants to experience with a raw signal, I am happy to make that possible.
Last edited by Richard L; Oct 4, 2008 at 01:32 AM.
#582
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Let me explain the reason for the ~0.5v at standby.
The algorithm to translate the turbine speed to voltage is quite complex because the update rate has to be very fast. To avoid sofeware glitches, a norminal 0.5V signal is generated to confirm the well being of the sensor for the DDS3's failsafe circuitry.
The latest flow sensor's body is made of metal. It can also be serviced by the user.
The algorithm to translate the turbine speed to voltage is quite complex because the update rate has to be very fast. To avoid sofeware glitches, a norminal 0.5V signal is generated to confirm the well being of the sensor for the DDS3's failsafe circuitry.
The latest flow sensor's body is made of metal. It can also be serviced by the user.
Last edited by Richard L; Oct 4, 2008 at 02:52 AM.
#583
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Richard, on my Aquamist pumpt on the bottom of the "black cap" end of the pump there is a small metal plate with 3 screws in it. They were coming loose from vibration and my kit started leaking a little. I accidentally over tightened these screws and now they are stripped. Can you please tell me where I can get some replacement screws? Maybe if I had the length, diameter and thread pitch I could find some locally. Thanks in advance!
#584
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I don't keep many Shurflo spares, such as a larger size screw. YOu should be able to find them locally. If this fails to cure the pumphead, it will cost abput $20 +$10 shipping from UK.
I need to order them from the UK shurflo office.
All our Shuflo pumps are purchased from CA and re-packed along side our UK kits in New Jersey. I never see these pumps. I have to reply on Shuflo's quality control.
I need to order them from the UK shurflo office.
All our Shuflo pumps are purchased from CA and re-packed along side our UK kits in New Jersey. I never see these pumps. I have to reply on Shuflo's quality control.