Required Fuel setting.
Moderator: LT401Vette
Required Fuel setting.
Hate to ask such a basic question but "search" didn't turn up anything.
"Required Fuel" setting. After I fill out the calculator, what is the unit of measure the answer given is in?? cc/min??
For example, mine is 10.3. Thanks.
"Required Fuel" setting. After I fill out the calculator, what is the unit of measure the answer given is in?? cc/min??
For example, mine is 10.3. Thanks.
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- Super MS/Extra'er
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Re: Required Fuel setting.
It's the theoretical pulse width in milliseconds that it takes to fuel the engine at 100%ve and 100kpa or 0 inches vacuum
Volvo 940, 2jzge, MS3Pro, daily
240Z, 2JZ, MS3Pro boost control
240Z, 2JZ, MS3Pro boost control
Re: Required Fuel setting.
Thanks, whats the box below it designated ms for then
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- Super MS/Extra'er
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Re: Required Fuel setting.
The amount of fuel to be injected, in milliseconds, as nathan pointed out above......107merc wrote:Thanks, whats the box below it designated ms for then
Ken
Last edited by kjones6039 on Mon Oct 27, 2014 12:17 am, edited 3 times in total.
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/extra 3.4.2 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
TinyIOX from JBPerformance
MS2 v3 w/extra 3.4.2 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
TinyIOX from JBPerformance
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- Running MSx/Extra
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Re: Required Fuel setting.
Just take it as the amount of fuel required by the engine (RF) ....if you have two injectors firing the fuel in , the number in ms would be half the RF..
John
John
Re: Required Fuel setting.
Sorry to be so slow, I understand that the ms box is the injector pulsewidth in milliseconds (in my case 5.15) required to supply the fuel for a single injection event. I assumed that the number in the larger box ( in my case 10.3)
was the actual amount of fuel required. If true, in what unit of measurement is the 10.3, being displayed?? lbs/hr, cc/min, or am I completely off. Or does it even matter. Thanks for responding, I am definitely on a learning curve.
was the actual amount of fuel required. If true, in what unit of measurement is the 10.3, being displayed?? lbs/hr, cc/min, or am I completely off. Or does it even matter. Thanks for responding, I am definitely on a learning curve.
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- Super MS/Extra'er
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- Joined: Tue Sep 14, 2004 4:17 pm
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Re: Required Fuel setting.
It's still in milliseconds. The larger number is the fuel required, but you must be using 2 squirts per cycle so it's cut in half then. So you see 5.15 per event and the total is 10.3 milliseconds
Edit, change your tune to 1 squirt per cycle and both numbers will match
Edit, change your tune to 1 squirt per cycle and both numbers will match
Volvo 940, 2jzge, MS3Pro, daily
240Z, 2JZ, MS3Pro boost control
240Z, 2JZ, MS3Pro boost control
Re: Required Fuel setting.
the measurement is in time, not volume. the volume the injector outputs affects what time it should be spraying.107merc wrote: in what unit of measurement is the 10.3, being displayed?? lbs/hr, cc/min, or am I completely off. Or does it even matter. Thanks for responding, I am definitely on a learning curve.
the top box it the ms required to achieve a stoich ratio at 100% ve at 100 kpa per each engine cycle.
the lower box is the ms required " " " " " " " " per each injection event. ie if the injectors squirt twice per engine cycle it will be half of the box above it.
Re: Required Fuel setting.
Thank you. now it's clear. I appreciate everyone taking the time to respond. Is there a formula that will let me calculate the actual amount of fuel
being dispersed at 10.3ms@...psi? plus injector size? Again thanks.
being dispersed at 10.3ms@...psi? plus injector size? Again thanks.
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- Super MS/Extra'er
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Re: Required Fuel setting.
Wouldn't that be the reverse of the inputs? So since it's 100ve at 100kpa based on the XX lb injector you put in, it would the injector size your using?
Volvo 940, 2jzge, MS3Pro, daily
240Z, 2JZ, MS3Pro boost control
240Z, 2JZ, MS3Pro boost control
Re: Required Fuel setting.
This is what I was looking for "injected fuel quantity is determined by pressure, flow rate and pulsewidth in ms" but I can't find a formula to plug the numbers into.
Any info appreciated.
Any info appreciated.
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- Super MS/Extra'er
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Re: Required Fuel setting.
Just multiply the injectors flow rating by the ms relative to the rated time period.107merc wrote:This is what I was looking for "injected fuel quantity is determined by pressure, flow rate and pulsewidth in ms" but I can't find a formula to plug the numbers into.
Any info appreciated.
If the injector rating is in lb/hr, there are 3600000ms in an hour. So:
fuel per squirt = (sprayTimeInMs / 3600000) * flow rating.
your fuel per squirt will be in lbs.
If the injector rating is in cc/min:
There are 60000 ms in a min, so:
fuel per squirt = (sprayTimeInMs / 60000 ) * flow rating.
your fuel per squirt will be in cc's.
if you want your output units to be different correct from there.
If your flow rating is altered by running at a different fuel pressure than the injector was rated at, you can calculate the new flow rating using this:
new flow rating = Square Root (new fuel pressure/rated fuel pressure) x rated flow
Phil Tobin
EFI Analytics, helping to simplify EFI
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EFI Analytics, helping to simplify EFI
Next Generation tuning software.
Supporting all MegaSquirt versions and firmwares.
http://www.TunerStudio.com
http://www.efiAnalytics.com/MegaLogViewer/
Support the firmware running your engine:
http://www.msextra.com/doc/donations.html
Re: Required Fuel setting.
Thank You.