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View Full Version : Winfred question about these timing figures...



Jon K
04-24-2006, 08:00 AM
I know it may not make too much sense but I am trying to see what my spark events should be under the MegaSquirt ECU - I need to setup the wheel decoder to decode the crank 60-2 signal. A fellow from the MSEfi.com forum told me to do this:

Try this:
Trigger angle = 60 BTDC
Cranking advance = 12
Trigger A = 46
Trigger A return = 54
Trigger B = 6
Trigger B return = 14
Trigger C = 26
Trigger C return = 34

How did I do that ?
The wheel rotates clockwise and on a 60-2 the first real tooth after the gap (i.e. to the left) is tooth no. 2. The last tooth (i.e. right of the gap) is no. 59.
Counting back, I see the VR sensor is pointing to tooth no. 56 @ 0BTDC.
I then decided that a 60deg trigger angle sounds about right, so figure out what tooth number the VR sensor would point to at 60BTDC. As the teeth are 6deg apart, this is 10 teeth back i.e. 46.
We want a cranking advance of around 10deg. The nearest tooth to that is no. 54 at 12BTDC, so put 56 for trigger A return and set the cranking advance to 12BTDC.

Trigger B is 120deg ie. 20 teeth later.
Trigger C is another 20 later.

hope that helps

I have no idea what any of that **** means... can someone help me out?

winfred
04-24-2006, 08:13 AM
uhhh....ill think about it after i get home when i have time

Jon K
04-24-2006, 10:00 AM
Not a prob - it makes sense in my head but i have no idea about timing - also, do we use timing lights/strobes on M50s ever?