E30M3 Running a SR20VE CAS with a chipped S13 ECU... on the Stock S14 BMW engine. Triggering help

[mochajim]

Hey guys,

I have a crazy car I imported for Japan awhile back.... It is a 1990 E30 M3 that is running the OEM S14 Engine, but has a CAS from a SR20VE, Coil on plug from a Nissan Gloria, all running a Nissan S13 ECU with a custom chip on it.  Long story short, I bought a g4x plug and play from an S15 since it just plugs in.  I confirmed the ECU fires all injectors, all Coilpacks, and can scale the TPS.  My Major hurdle now is setting up the triggering for the engine since it has CAS from a SR20VE.  I assume my first steps are to find out where TDC is and mark that on the crank pulley and start from there?  Would it be a good time to throw my AEM trigger wheel into the cas?  

[Adamw]

When you say an "S14 engine", are you talking about a BMW S14 or a Nissan S14? 

If it ever did run on the stock ecu then the trigger offset will likely be as per our SR20 base maps.  But a quick test you can do: 

Disable ignition, or unplug coils.  Set the trigger mode to Nissan 360 opto.  Remove all spark plugs except cyl number 1.  Then do a trigger scope capture while cranking.  We should then be able to have a rough guess at the offset from that.  

[mochajim]

BMW S14 Engine.  Yeah I know it's confusing since I have a Nissan S13 ECU....   The car is currently running a Nissan s13 with a custom rom on it.  Here is the picture of said engine.