JOOLZ!

How does the BMW twin spark ignition system work?

Is each cylinder fired off the same coil or does each spark plug have different coils (COP)?
Does the ecu fire the coils or is there a separate ignitor box?
Are the coils CDI or inductive?

I'm trying to find a way to run twin spark from Microsquirt which only has 2 logic-level, 5v, ignition outputs.

cheers!

Harley

1-2-Spark can do twinspark to. There's place at the pcb. for 4 ignitiondrivers.
So the possibilities in a 2cv you can do are......

A) 1 ignitiondriver - 1 coil wasted spark, (2cv/visa yellow Harley (no not you )) (Standard)
B) 2 ignitiondrivers - 2 seperate coils 1 plug each wasted spark, (universal coils)
C) 2 ignitiondrivers - 2 coils on cop wasted spark(coils on plug)
D) 2 ignitiondrivers - 2 separate coils wasted spark twinspark (2cv/visa yellow Harley)

This you can do now already.

So soon you can do this:
E) 2 ignitiondrivers - 2 seperate coils 1 plug each sequentiial (universal coils)
F) 2 ignitiondrivers - 2 coils on cop sequential (coils on plug)
G) 2 ignitiondrivers - 2 separate coils sequential spark (2cv/visa yellow Harley twin spark))

H) 4 ignitiondrivers - 4 seperate coils sequential spark twinspark (4 universal coils each 1 plug)
I) 4 ignitiondrivers - 4 coils on cop sequential (coil on cop)

So tell me which option you want and I make it for you. btw. each extra ignitiondriver mounted will set you back 7,50 euro........

As you see theoreticly it van do 4 cilinder sequential already or a V8 wasted spark need only to programm it (peace of cake (not).

Hi Harley, depends exactly what age you're talking about. The 1100 models use a single coil wasted spark driven straight from the ECU, as do some of the early 1150s. In around 2004 they went to twin plug heads, at this point the primary plugs changed to coil on plug but the secondary plugs got to share a single conventional coil, still wasted spark and still driven directly from the ECU, I think, at least there's no other intermediate boxes.

As to whether the coils are CDI or inductive, I don't know, how would I tell? I haven't got a wiring diagram for the COP models, although my engine is that type and at the time of fitting them I could have told you how they were wired up, but not any more... I can tell you the COPs have a three wire connection (+,-,ecu, I think).

I think the 1200 models went to all COP.

Thx for the info Joolz.

I'm have been looking into upgrading to the Microsquirt ecu I need a dual channel external ignitor box to run two dual coils for the twin spark setup I have.
Something like this, from a Honda RC-51 RVT
This ignitor box has 6 wires. Plus, minus, two inputs, two outputs.
It works with a 5V signal.

CDI coils are grounded/share common ground.

Cheers,

Harley