Trailing timing, pros/cons with 0deg. Split?

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May 11, 2005 | 07:54 AM

#26

muythaibxr

MegaSquirt Mod

Joined: Sep 2004

Posts: 4,721

Likes: 1

From: Maryland

Quote:

Originally Posted by rotarygod

I was right though about the number of teeth. It has 24 on the bottom wheel and 2 on the top. It just spins at half of engine speed so the ecu only interprets it as 12 and 1.

I haven't been over there in a while. I'd like to try running a cas with megasquirt but as of yet don't know how. Did you have any detailed instructions on what to do?

You have to build a dual lm1815 circuit to condition the VR sensor outputs from the CAS, then hook the 24 tooth conditioned output to pin 6 of U4 on the megasquirt, and hook the 2 tooth conditioned output through a 1k resistor to pin 11 on the megasquirt CPU...

Then run the wheel decoder with 12 teeth and extra input, set the triggers to 1,3 and 7,9, set cranking mode to trigger-return, trigger angle of 60 deg BTDC, use Dwell Control, but you can use a very low dwell b/c the mazda ignitors seem to almost double it, I think 1.9 ms was the value I saw....

I don't think I've left anything out.