compuw22c

Yes, another thread about injector dead times...

In this case, I have "Manufacturer Data". "Manufacturer Data" is in quotes because despite being available, its a bit unclear even after a phone call exactly what this data represents. As you can see in the screenshot, I have what is referred to as "Battery offset data", which makes total sense as I understand dead times change with vehicle voltage. However an "offset" typically refers to an amount that you add or subtract from a given value, and I don't seem to have that value. It's possible this value is the manufacturer's listed "minimum opening time" of 1.1ms, and according to an old post that I found on here with older datasheets that used to ship with the injectors, that's the opening time at 17v so I'm not sure exactly what I'm supposed to do with this data as adding it to 1.1 doesn't seem to line up with anything based on the old data sheet (assuming it's still accurate, which it may not be).

I did call Deatchwerks, and the first response was that they don't provide tuning advice (my neck hurts fro the head shaking). The next response was that the offset data IS the latency (how long the injector takes to go from closed to open), to which I then asked why their 350cc injectors list a negative value for the offset, to which he then got confused... I reiterated that I'm simply asking about the characteristics of the injectors that they manufacture and I purchased and not tuning advice, and to his credit he did take down my email and may get back to me with information...

In the meantime, I'm trying to figure some of this out myself. Using the older datasheet I found on this forum, I did enter the appropriate values however when my fans kick on I do see a voltage drop (already ordered a delay to delay the second fan by about 5 seconds) and when that happens, I go very lean for maybe a second until it recovers from this voltage drop (I can see it very clearly on the logs, once it went higher than 20:1) and so I'm guessing this is not the correct information. In addition, I can't see how any of the data from the "Battery Offset Wizard" corresponds or lines up with any of the data I have from the old data sheet. If anyone can help me in interpreting this data and help me find my actual dead time/latency in MS per each volt, I can then calculate the necessary percentage values that Megasquirt wants to see in excel very easily (as I did with the old data).

Any help in interpreting this exercise in detective work would be greatly appreciated...