Originally Posted by
ATPCummins
That is all that I have put together right now. It should give you enough info to get going. Then, when you come up with specific questions on your tune you can post them in the forum.
Thank you Mike For writing that article it was well written and geared towards beginners (me) but I thirst for more!
Coming from a gas tuning background, I am having a hard time determining the reason that we have pilot injection and how it affects the main fuel injection.
From the little I understand, it seems that once the engine is up to speed at cruising speed you dont want much advance
So the initial questions I have are
1. Since diesel takes time to burn and it burns under combustion, why would there ever be negative numbers in that table?
2. What exactly is a mm3 and why does it go from 0-150? I assumed it was a % throttle but that doesnt really make sense.
Thank you for the great article but I just want to know more about how this stuff works!
This is my stock chart from the timing calculator. Why is that one cell red all by itself? Is this like a strims/ltrims tables in the gas world where it adapts over time?
Code:
FUEL TIMING CALCULATOR
Each cell in this table contains the percentage of fuel pulse width that will occur before, at or after top dead center (TDC). After making changes to the data in this table, click the [Apply] button to update the fuel timing angles in A9209 so that the specified percentage of the fuel pulse will be delivered before, at or after TDC.
For example, assuming the fuel pulse width for a particular cell (as shown in A9203) is set to 500us:
If a cell contains 200%, the start of the pulse will occur 1000us before TDC.
If a cell contains 100%, the start of the pulse will occur 500us before TDC.
If a cell contains 50%, the start of the pulse will occur 250us before TDC.
If a cell contains 0%, the start of the pulse will occur at TDC.
If a cell contains -50%, the start of the pulse will occur 250us after TDC.
If a cell contains -100%, the start of the pulse will occur 500us after TDC.
If a cell contains -200%, the start of the pulse will occur 1000us after TDC.
This calculation uses values from A9220 “Fuel Pressure” and A9203 “Main injection pulse width”. If the values in those tables are not accurate, then the calculator may not produce accurate results.
For example, the first column of data in A9203 may be calibrated to be all zeros which will cause this calculator to set the corrsponding first column of data in A9209 to be all zeros.
You may prevent this calculator from adjusting any cells by masking those cells in A9209 using the “Enable/Disable edit mask (Ctrl+E)” toolbar buttons before clicking on the [Calculator] button.