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Re: OK, so now it's a puzzle Posted by JimBlake [Email] (#141) [Profile/Gallery] (more from JimBlake) on Fri, 29 Jan 2010 06:02:57 In Reply to: OK, so now it's a puzzle, Erik919kt, Thu, 28 Jan 2010 15:54:42 Members do not see ads below this line. - Help Keep This Site Online - Signup |
I guess I was ambiguous about how it flips. From the standpoint of what the IDM "thinks" it's doing, it IS mirrored.
#1 cylinder is fired by #4 coil of the IDM
#2 cylinder is fired by #3 coil of the IDM
etc...
With the IDM installed "correctly", starting with #1&4 at TDC...
spark 1,4 - #1 fires & is detected by ionization voltage
spark 2,3 - #3 fires & is detected
spark 1,4 - #4 fires & is detected
spark 2,3 - #2 fires & is detected
after a couple revolutions it knows which one to fire.
With the IDM in "backwards", it's like this:
spark 1,4 - #1 fires but it's #4 on IDM
spark 2,3 - #3 fires but it's #2 on IDM
spark 1,4 - #4 fires but it's #1 on IDM
spark 2,3 - #2 fires but it's #3 on IDM
So it's just offset by 360(crank) or 180(cam).
This only works because there's no physical cam-position sensor. It's done by detection of which spark plug is actually seeing combustion. With a Honda-type detection scheme where the actual camshaft position is detected, it wouldn't work.
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