megasquirt coilpack to cop swap

[bluto5]

 soo.. this is info on my up coming switch to coil on plug(cop)  from coil pack and megasquirtsoobrxdrivingfun in general. thanks to northwet for encouraging public discourse.

 

this will be done on an ms2 v3.0 029y4(?)msextra firmware attched to my ej22t/dohc with a 36-2-2 crank timing belt gear/ crank trigger from a later ej motor.

 

The current coil pack is an ej25d unit that matches the heads/intake. the cop's i will be using are svx( dumb coil, no ignitor). the change to the ecu will be a change of scale rather than design. the hardware is wired in the same but 2 more drivers are needed because the coil count goes from 2(2 coils in a coil pack) to 4

 

wrx/sti(smart coil, on board ignitor) are also an option with slightly different(simpler over all, no drivers required) ecu configuration.  

 

 

If you go here..

Megasquirt (V3.0 board) - Spark/ignition output

 

and scroll down to here..

Three or Four Coil Outputs (6 and 8 cyl Wasted Spark or 4cyl COP without ignitors) --its a long page--

 

You can see the technical bits of what im going to be doing. All the info to modify the ms hardware for this operation is provided. 

 

Ill try and show some of the grunt work of whats involved. i have run on both dumb and smart cop coils, various coil packs and old style coil w/distributor.

 

Sam

Edited July 9, 2013 by bluto5

[NorthWet]

Good start!  It is interesting to see the approaches used by the MS folk.

[bluto5]

ms2 v3.0

 

 

things to note...

 

The driver on the far right on the heat sink is coil output 1 and is standard.

 

The driver with external wiring is coil output 2 and has been added on.

http://www.diyautotune.com/catalog/bosch-bip373-coil-driver-mod-kit-p-230.html

 

Same as the 2 to come. this is a bosch part with built in fail safes.

 

 

im using a zeal engineering daughter board (the board in the lid of the case)

http://www.diyautotune.com/catalog/zeal-engineering-daughterboard-with-dual-vr-conditioners-p-378.html

 

i have the crank signal(36-2-2 crank timing pulley) coming into this board to be "conditioned" for the ms processor. its going from an analog signal to a digital.  this could be processed by an on board conditioner but its been reported that the zeal board works better.  if cam and crank signal were to be used, the board or some other conditioning circuit would be needed.      http://jbperf.com/dual_VR/v2_1.html  is another option

 

The board also sends out my tachometer signal. This could also be done by the main board pretty easily.

 

more to come..

 

Sam

Edited July 11, 2013 by bluto5

[NorthWet]

Is the Zeal board the most popular?  Are there other common ones? 

 

(I slip on my Devil's Advocate disguise):  I noticed that the Zeal uses the LM1815 IC for the VR signal conditioning. The posts that I have seen so far on other forums (reliable source for all information, right? snarkmark) tend to prefer the MAX9924-series as giving a more reliable signal.  Based on that, I have been looking at the MAX9926 rather than the LM1815.  If people are happy with the Zeal board, I probably should do some more research.  (I remove my disguise.)

 

Another website to browse around in!

[NorthWet]

As I mentioned to the OP on another thread, I am considering going COP on my EA-series engine.  Besides the "cool factor", my interest is to reduce/eliminate high-tension wiring/circuit issues that have annoyed me over the years, especially in the EA82T.

 

So, what is behind your desire to switch to coil-on-plug?

[bluto5]

The zeal board has been in wide distribution for awhile and i have used it several times myself.

 

jbpef also offered a diy board that i have used. also with the lm1815. I edited my first post to list the current offering that is all surface mount and has a small foot print. im not sure of the chip used.

 

 

I know some just bread board/proto area the circuit.

 

The lm1815 always done the job "well enough".  i often have signal noise on the cam and crank signal to deal with when using vr sensors. its overcome with filters, proper wiring practices and sensor alignment but who knows if stuff would be easier with a different chip.

 

 

As for the cop swap reasoning, I like the cleaner packaging and less wear parts.  Its just as easy to set up the ecu one way as the next i usually differ to cop when im able.    Also, it was time to build a proper engine harness and if I was doing that then it was going to have cop wiring at least in it.

 

thats the other wonderful thing about MS(all stand alones really).  I can swap motors with reckless abandon. I have had a 251(w/ 6/7, stock coil pack) swapped and putting on miles on this same ecu and harness in my soob. any other would be just as easy with a few adjustments.  next motor going in is going to be a ej25d with turbo and meth. Ill swap that one to a 36-2-2 tho.

 

  I also tend to prefer distributor-less system. all depending on application and parts availability of course.

 

Sam

[bluto5]

mmm, wiring.

New harness with good condition stock plugs spliced in.  I still havent seen anywhere to buy subaru pins and connectors. The unslpiced wires in the middle will be clt temp for the ecu and gauge and intake air temp.  The bunch at the end will likely be spliced into a soob engine harness plug.

 

little bit closer now..  Ill be swapping injectors soon after this wiring swap happens. just a re-splice here and a re-splice there.. same for a jump to wrx/sti coils if i get my hands on a few sets. I love zip ties.

 

little bit closer now.. This is how i build harnesses if i cant run new plugs and pins. Crimp with gooey heat shrink.  Ive soldered all joints before(2 harnesses?) and to me this is easier and more reliable. especially on large gauge wire and connecting more than 2 wires in one spot.

 

After this it gets all wrapped up in nylon braided split loom and most of the zip ties cut out.

 

Route it, hook it up and tie it down.

 

Im not exactly sure when ill get around to doing this. Its on the list of things to do before i swap motors tho.

 

Sam