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Question about 60-2 trigger with camsyns and VR polarity (logs inside)

Started by ZoLtaR, March 16, 2011, 07:29:52 PM

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ZoLtaR

Now I understand a little bit more ;) Ok I will do as you said with strobe light.

The most important thing for me is the order of the ignition / injection tables, that's why i asked so many question about it. To understand things easier can I assume that I should always set injection order the same as ignition ? For example 4 cyl engine, with 1-3-4-2 firing order.

Firing Coil on cyl 1 -> Injection on cyl 1
Firing Coil on cyl 3 -> Injection on cyl 3
Firing Coil on cyl 4 -> Injection on cyl 4
Firing Coil on cyl 2 -> Injection on cyl 2

If it's okay then, screenshots of tables below should be correct.

mattias


ZoLtaR

Ok cool, now almost everything is pretty clear for me.

The hardest thing to understand for me is trigger reference tooth idea. And understanding how it should be set to a specific application.

mattias

It is quite complicated because it is designed to support even and odd fire and many strange trigger wheels.
The trigger reference tooth which is "0", is the first trigger tooth as defined by the primary trigger settings, every TDC then follows every 30 teeth in your case (4 cyl, 60-2 trigger wheel).

ZoLtaR

ok but in wasted spark it's always set to

0
30
0
30


in my camsync case it's set to

0
90
60
30

don't get it. :)

mattias

It's no mystery.

Without cam sync there is no way to  reference more teeth than what you have on the primary trigger wheel on one rotation = 60 teeth including the missing ones. The primary trigger count is then reset on every revolution and you can only use a distributor or wasted spark.

With cam sync the signal appears every two rotations, and it's possible to reference the entire 4-stroke cycle = 60+60 = 120 teeth, and make it possible to identify every single cylinder event.

ZoLtaR

Thanks mattias again. Every post I know something new about triggering.
Tommorrow I will check this application with strobe light and give you a note.

ZoLtaR

Today I checked whole system with strobe light. With 0,90,60,30 reference table i'm getting spark on cyl.1 when it is in BDC (bottom dead centre). So then it seems that whole sequence is moved 180 degree from fine position.

When I changed table to 30,0,90,60 everything seems to be fine. But it's recommended to have tooth 0 on top. So what to do now? Is there any possibility to fix it and get proper sequence with 0,90,60,30 ?

Erikk

Yes, just move the whole ignition output-table one step and you´re all set.

ZoLtaR

Ok so reference table looks like this. ECU reads it backwards so this is proper sequence with 0 at the top (0, 90, 60 ,30). Am I right?



And then just adjust ignition table to suit with the trigger table events?

mattias

Your picture is wrong, it must read :

0
90
60
30

Adjust the ignition table outputs until cyl 1 fires at the correct TDC, remember - there are two TDC situations but only one is correct with COP, both are ok with wasted spark.

ZoLtaR

Ok I get it, but how to recognize it fires at right TDC. We have 720 deg (2 rotations) for full sequence in 4 cyl four-stroke. So how to recognize it's right for cyl.1 TDC , and do not mismatch it with cyl. 4 TDC ?

mattias

It will only run and start with the correct order, so you can try it that way and just shift two steps in the ignition outputs if it doesn't.
.. or you can check when cyl 1 valves are closed and mark that on the cam sprocket and strobe against that.

I'd just try either of the two possible ignition orders.

ZoLtaR

I was thinking about making mark on cam gears in position where cyl.1 should fire. That's very good idea and will give me a final answer.

In this case, cylinder 1 has a reference tooth 0 or 30 ?


0  - cyl4
90 - cyl3
60 - cyl2
30 - cyl1

or?

0 - cyl1
90 - cyl4
60 - cyl3
30 - cyl2

mattias

You're not listing the cylinders in firing order, so it makes no sense.
Actual order : 1 3 4 2

In the ignition output table they appear like this, and you should shift the table to find which position makes cyl 1 appear in the correct place. It depends on where your cam sync pulse occurs.

2
4
3
1


This is the same table, only shifted one step :

1
2
4
3