1st SETUP injectors (flowrate, rate modifier, Min pulse width, PW adder)
10-12-2007, 09:05 AM
#26
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That number is too high to run at idle. The amount of fuel needed to sustain 15-1 a/f at idle on our mouse motors is less than 1.0ms which is why you are showing a rich condition.
Set the min. pulse wdith to about half that and use the short pulse adder table to add pulse width to values below 1.0ms in a progressive fashion. (something like .1ms at 1.0, then 12.5% less at every value below that until you hit 0 which your adder would also be 0.....the interpolate function is good for this).<----Just an example, don't quote me on those numbers. Basically you have to play around with the short pulse adder table and find the rates that allow a smooth idle and smooth sweeping air-fuel gauge. Jacking up the idle a little is another easy fix and will become almost necessary as you increase the pipe diameter the o2 is housed in as o2 switching speed becomes an issue at idle.
I think the advertised min. pulse width for 650cc injectors is like 1.1ms at 100kpa (atmospheric) so at lower pressure it will obviously also be a lower possible pulse width.
Set the min. pulse wdith to about half that and use the short pulse adder table to add pulse width to values below 1.0ms in a progressive fashion. (something like .1ms at 1.0, then 12.5% less at every value below that until you hit 0 which your adder would also be 0.....the interpolate function is good for this).<----Just an example, don't quote me on those numbers. Basically you have to play around with the short pulse adder table and find the rates that allow a smooth idle and smooth sweeping air-fuel gauge. Jacking up the idle a little is another easy fix and will become almost necessary as you increase the pipe diameter the o2 is housed in as o2 switching speed becomes an issue at idle.
I think the advertised min. pulse width for 650cc injectors is like 1.1ms at 100kpa (atmospheric) so at lower pressure it will obviously also be a lower possible pulse width.
That's basically what I am doing, but tuning the adders is a major PITA.
10-12-2007, 10:44 AM
#27
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tell me about it, I just changed my tune and it runs great...
I have had a few times where it cuts out on me and the rpms fluxuate right before....I'm stumped..
I have had a few times where it cuts out on me and the rpms fluxuate right before....I'm stumped..
10-12-2007, 11:49 AM
#28
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This is what my adder table is looking like now:
0 0.125 0.25 0.375 0.5 0.625 0.75 0.875 1 1.125 1.25 1.375 1.5 1.625 1.75
0.85938 0.73438 0.61719 0.5 0.39844 0.27344 0.16406 0.13281 0.11719 0.04688 0.02344 0.00781 0.00781 0.00781 0.00781
0.85938 0.85938 0.86719 0.875 0.89844 0.89844 0.91406 1.00781 1.11719 1.17188 1.27344 1.38281 1.50781 1.63281 1.75781
The top line, is the adder cell. The next is the adder value. The third is the total of the 2, which is how I know which cell to change. I have a few histos that I created to let me know what the actual PW is when getting errors. The example above is a recent, "start over again" table, so it still has some errors, but all in all I think I am on the right track.
0 0.125 0.25 0.375 0.5 0.625 0.75 0.875 1 1.125 1.25 1.375 1.5 1.625 1.75
0.85938 0.73438 0.61719 0.5 0.39844 0.27344 0.16406 0.13281 0.11719 0.04688 0.02344 0.00781 0.00781 0.00781 0.00781
0.85938 0.85938 0.86719 0.875 0.89844 0.89844 0.91406 1.00781 1.11719 1.17188 1.27344 1.38281 1.50781 1.63281 1.75781
The top line, is the adder cell. The next is the adder value. The third is the total of the 2, which is how I know which cell to change. I have a few histos that I created to let me know what the actual PW is when getting errors. The example above is a recent, "start over again" table, so it still has some errors, but all in all I think I am on the right track.
11-01-2007, 03:06 AM
#30
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Questions:
When I'm tuning in VE....my idle is jacked!! Spark jumps from 5 - 12 and fuel sweeps from 13.2 - 16.0 . It seems like no matter what I do....it still does it. If I'm tuning MAF WB sweeps like 14.4-15.0 and timing is fine....nice smooth idle. How do i fix this idle in VE?
Kennyspec: you said "set PE Enable MAP to 115kpa ~ 3 psi"
115 KPA is 16.68 PSI....did you mean 15 kpa?
When I'm tuning in VE....my idle is jacked!! Spark jumps from 5 - 12 and fuel sweeps from 13.2 - 16.0 . It seems like no matter what I do....it still does it. If I'm tuning MAF WB sweeps like 14.4-15.0 and timing is fine....nice smooth idle. How do i fix this idle in VE?
Kennyspec: you said "set PE Enable MAP to 115kpa ~ 3 psi"
115 KPA is 16.68 PSI....did you mean 15 kpa?
11-01-2007, 09:26 AM
#31
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VE is more sensitive to other errors. Sounds like an adder issue, but I would need to see your tune and log. As for kPa, you are using the wrong conversion. Yes, 115 kPa is 16.5 psi, but barametric pressure is 14.5 psi. That means that 100 kPa (14.5 psi) is 0 psi of boost. 115 kPa is about 2 psi boost (or so). (115-100)*0.14504 = 2.1756 psi of boost.
02-29-2008, 11:39 AM
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The short pulse limit tells the ECM when to look to the adder table, so set that to where your adders start. For instance, if you set your adder table to start ramping PW from 1.125ms to 0ms, set your short pulse limit to 1.125ms. The min PW isn't really that big a deal, since if your adders are set up properly, you will see a min PW of whatever your adders says. I have mine set to .102ms but because of my adder tables I never see less than .6ms or so.
05-29-2008, 07:38 PM
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I just bought hptuners and am very new to tunning. my first question is how do you cal. your g/sec and come up with a flow rate for 42.5lb injectors? is the fuel psi at wot or part throttle? sorry if I come off as a noob.
02-04-2009, 12:24 AM
#37
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Using SJSchafer's old formula of cc/min * .103 = lbs/hr, my flowmatched 60# injectors were calculated as 71.4 lbs/hr, which seemed really odd. I did a quick google and found on other forums that the proper formula is actually cc/min / 10.5 = lbs/hr, giving me the much more reasonable 66.1 (which also matches the numbers provided from the flowmatching company), and doing 630/10.5, gives you exactly 60.
Just on the off chance someone was using that formula to calculate the flowrates, I figured this could help.
Also, this spreadsheet is awesome and is the one everyone in the thread keeps referencing.
http://www.thetuningdoctor.com/Excel...orscalels2.xls
03-09-2009, 11:54 PM
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ok question just so i think i understand something...
EQ Ratio Vs.RPM table is
1.300 across the board... which is calculated by 14.7/11.3=1.300 i figured 11.3 would be safe to start..
at WOT im getting around 10.3 or so... would i need to command something higher than 11.3 to get WOT afr correct... or is there something in my ifr tables or adders?
short pulse 2.000
adder is 0.00 across the board
any help would be awsome thanks... just learning all this...
also my idle flucuates most of the time after coming to a stop... and afr jumps
EQ Ratio Vs.RPM table is
1.300 across the board... which is calculated by 14.7/11.3=1.300 i figured 11.3 would be safe to start..
at WOT im getting around 10.3 or so... would i need to command something higher than 11.3 to get WOT afr correct... or is there something in my ifr tables or adders?
short pulse 2.000
adder is 0.00 across the board
any help would be awsome thanks... just learning all this...
also my idle flucuates most of the time after coming to a stop... and afr jumps
Last edited by Jrhdpaintball; 03-09-2009 at 11:54 PM. Reason: Automerged Doublepost
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