Ignitech triggered by IE pickup

[Speeddog]

I've been wanting to do this for quite a while.
There's a nagging suspicion that I'm reinventing the wheel, but I've searched a good bit, and not found any evidence of anyone doing it.

My trusty '98 carbie 750 is going to be the victim of this experiment, pretty much normal service there.
It's got an Ignitech running off of the OEM carbie crank triggers, and it works quite well.
And 'works quite well' is generally a good enough reason to start messing with it...

Didn't have an IE alternator cover, at least without robbing it off of a complete motor, which is a slippery slope I try to avoid.
Scored a nice one from Duck-Stew a while back, thanks man!

Didn't have an IE layshaft gear either, looked through all my spares and no luck.
Recently in a bit of reorganization, I found one.

Suitably chuffed by having all the parts in hand, today I commenced to do the swap.
Pulled the alternator cover off.
And discovered that it already had an IE layshaft gear.
 

My annoyance was soon overwhelmed with the realization that I then didn't have to pull the flywheel off to R&R the layshaft gear.. so time saved and aggro reduced.

Spent a bit of time with the naked IE cover clapping it on and off peering in the hole at the layshaft gear.
Quite a bit easier to do with the crank in various TDCs and spark positions aided by the carbie flywheel and trigger coils to use for reference.

The slot is clocked to the crank in a rather odd orientation, not sure why it's that way.
Certainly not the way I'd do it, given how sensible the arrangement of the carbie bits are.
But Ducati have yet to call me and ask how I think things should be done.
So embracing the philosophy of KISS, I'm pressing on with it as is.

The leading edge of the slot appears to be clocked to the minimum idle advance position of ~6 deg on the horizontal cylinder.
But on TDC overlap, not TDC spark.
Odd.

I'm hoping that the Ignitech watches the intervening teeth passing by to accurately determine when to do the spark.

[Dirty Duc]

Sweet baby Jehosaphat! That helps. I was confused as to tooth count vs. spark...

[koko64]

Im on board. Wondered how this would work. Did Ignitech make a unit to order that was plug and play?
Be watching how it goes.

[Speeddog]

I'm under the impression that Ignitech offers (offered?) a wiring pigtail that would suit this task.
I sent them an email about it ages ago, never got a reply.
Not particularly worried by that, I suspect if they replied to every crazed email they'd get no work done and end up living in a cardboard box.

AFAIK, the unit itself is always the same, with variations in programming and wiring pigtail to suit the application.

The advantage of the configuration I've cooked up is that the existing functioning hardware is intact, and I've only added a sensor.
I intend to connect that sensor to a completely seperate Ignitech unit that I can fuss with, and even connect to a dummy set of coils and plugs if necessary.
I can check that dummy set with a timing light to get the kinks worked out.
Anyway, that's my story and I'm stickin' to it.
<Country and Western song reference that may not translate well to other locations  >

[Duck-Stew]

Best of luck with the wheel re-invention.

[hnracing]

The german fellow "Muschi", do not check what it means :-) , at ducati.ms used Ignitech on his 1000SS.
He got it pre wired and programmed, think it was just a mix up of the front and rear cyl and then it worked fine.
His base setting was:
idle is a 10°, than a rise beginning from ~1700 - 2000 rpm
up, ending at 4500 rpm, main advance is 28° BTDC.*
More info at
http://www.ducati.ms/forums/57-supersport/56514-900fi-engine-replacing-750carby-2.html

[koko64]

Great link. Cheers.

[ducpainter]

I certainly hope you all go over to .ms and post links to here.

[Dirty Duc]

The leading edge of the slot appears to be clocked to the minimum idle advance position of ~6 deg on the horizontal cylinder.
But on TDC overlap, not TDC spark.
Odd.

I'm hoping that the Ignitech watches the intervening teeth passing by to accurately determine when to do the spark.

Now that I have thought on this some more, when you say "leading edge of the slot" do you mean the beginning or end of the opening?

The way the Megasquirts read is: first tooth after missing tooth is #1. I don't have a carby flywheel to play with, but my calculation is that (pick an edge of teeth) each tooth is 7.5 real degrees and 15 engine degrees apart. I have been using teeth 18 and 23 for "triggers" for ignition events. This has been problematic... but is the only thing that has worked so far. I've tried both rising and falling edge (leading and trailing edge of the tooth) with no real change other than the anticipated 15 degrees of total timing added or subtracted from a running bike.

[Speeddog]

Leading edge of the slot is the beginning of the opening, in my coordinate system.

I've got pics, but I'm not sure I've got accurate notes from which to make sense of them.

[Dirty Duc]

So, by your coordinate system I should be using trailing edge of tooth 21 as TDC spark for the horizontal cylinder (and figure out from there where everything else is), assuming things are put together properly (as they were pro-assembled on the 749R). My base timing then would be the minimum idle advance of 6 deg.

TDC for vert should be on trailing edge on tooth 27, then?

[pepeducat]

I have mounted an ignitech on a 900 IE (for the 750 it's the same principle).
You need the alternator housing, the sensor and especially the return valve.

The housing with the hole for the ignition sensor



The sensor



And the distribution gear with the specific stall



Then for everything to work, you need a specific curve for your IGNITECH

https://mega.nz/#!pwwjybrS!xY0mh9cKqgSrH7sGMqAW5mWEtQwVZIEMvEXTPyR30AM

[Speeddog]

Mmmm, that's very helpful, thanks!   

Now to look at bits and think to (hopefully) get it straight in my head.

So, by your coordinate system I should be using trailing edge of tooth 21 as TDC spark for the horizontal cylinder (and figure out from there where everything else is), assuming things are put together properly (as they were pro-assembled on the 749R). My base timing then would be the minimum idle advance of 6 deg.

TDC for vert should be on trailing edge on tooth 27, then?

I'll try to puzzle that out.

[Dirty Duc]

Pepe's map says TDC on H is falling edge of tooth 23 and V is falling (trailing, or 2nd) edge of tooth 41.

I think it says ignition events can occur no earlier than the falling (trailing) edge of tooth 20 and 38, for a maximum advance of ~45 deg (plus or minus 6).

I think I know how my Megasquirt settings are screwed up now. Just need to fix the fuel system to test.

[Speeddog]

Pepe's map says TDC on H is falling edge of tooth 23 and V is falling (trailing, or 2nd) edge of tooth 41.

I think it says ignition events can occur no earlier than the falling (trailing) edge of tooth 20 and 38, for a maximum advance of ~45 deg (plus or minus 6).

I think I know how my Megasquirt settings are screwed up now. Just need to fix the fuel system to test.

I've drawn a pic of the gear with the slot, and a degree wheel outside of that.
Oriented it with the falling edge of the *slot* at 6 deg BTDC on Horizontal Overlap.
And continually reminding myself that it's not crank degrees!

Been scratching on it with a pencil, and it agrees with what you've just said.

You and Pepe have put the spokes in my wheel!