best trigger disc pattern

[0martin0]

can you please tell me what is best pattern to synchronise as fast as possible and measure cam angle precisely and so on?

i will expect 60-2 on crank with gap 90deg before TDC with reluctor sensor, and cam "level" with hall sensor to give ecu 0 from 0-360 and 1 from 360-720° but will it work with cam1=1tooth setup? i think firmware calculate more with edges then actual levels.

so some diferent setup will work better?

[PSI-Motor]

60-2 and a single tooth on the camshaft is extremly accurate.

[Karel]

there always question about

you can have best acuracy, but can end with too much info for ecu
or
low ammount of info for ECU and low accuracy.

20Years back was the calculation fastness the biggest issue, but not now. So some time back you would be best with 12-1 or something like that, but now you can use easly 60-2

[0martin0]

crank angle acuracy is not main issue.....

main issue is speed of synchronization

on 4 from 6 cars i observe lot of crank turns before proper sync

so cranking takes bit longer then i would like to see...

[Karel]

No problem on proper wiring, and good starter.
I have seen big trouble on old starter motor, on poor grounding of the engine, and on poor wirring-shielding..... nothing else

[0martin0]

here you can see what i mean,

this is 1.8t 20v

60-2 on crank and 1tooth on cam

cranking time is more than 1sec doesnt seems lot but it realy does not sound like you would like to hear

[0martin0]

here is how it should look...

vw 1.4 16v engine

60-2 on crank

no cam sync

wasted spark

[Karel]

If you dont sync on CAM, you dont need to wait for full 2 revolutions of the engine to get synced...... simple........ but you will end with no posibility of full sequential injection, or variable cam control.

I have seen few Honda S2000 with damaged starter on AEM EMS when selected "start without cam sync" ........... i dont see something bad on wait 1-2sec before start

[0martin0]

i can use ign out cranking to run "wasted spark" during cranking

but

question is what is best pattern to sync as fast as posible

thats what i ask for because on most engines i can ask whatever i want. so i need to know what is easiest to ecu to understood

for example maybee is better for ecu to have CAM signal before crank missing tooth maybee after,
maybee is better to have less tooth on crank because there is less chance that crank and cam tooth came in same time and so on

and from attached logs you can see that i take much longer then 2revs for ecu to see proper cam angle and fully synchronise

[nickbmw]

My S2000 also needs a lot of cranking to start, it is annoying.

[gregpe]

My S2000 also needs a lot of cranking to start, it is annoying.

start on 360 sync and them switch for 720 work perfect..

[GearTech_Greece]

Not possible on multitooth triggers

[RHD]

I ave often wondered about this exact same question???

What we need is an explanation or flow chart of how the ecu synchronizes. In many cases it is possible to choose the position of the cam signal and also first trigger tooth based on where you start the firing sequence.

So the question is: is it better to have a low first trigger tooth count? or a high first trigger tooth count?

And is it better to have a cam sync signal just before the missing tooth? or just after the missing tooth?

[Karel]

So i can tell you my last try. I was asked by customer do wiring and EMU install into his Samurai with implemented 1,4L engine from Swift. The engine has originally distributor and no crank sensor. I asked hit to implement 12-1 trigger wheel on crank pulley and an Hall sensor.
We are using Bosch COPs everything wired full sequentially, but injectors squirt twice per cycle and the ignition goes 1+4 and 3+2.....

It starts absolutly instant. If we would install also cam sensor, we can switch to full sequential after startup, but i dont see huge gains doing it.

SO the 12-1 works great in waste-spark mode.

[nickbmw]

A 12-1 and a 60-2 will both work the same, or not? How accurate is ignition advance timing control? Does the trigger wheel with the less teeth count induce high trigger delay? Judging from what the manufacturers do, the higher the teeth count is the better the accuracy is, and the misfire detection as well, which is not available with standalone ecus.

[Jadzwin]

The best solution is 60-2 + any cam pattern supported by EMU.
Then you start in wasted spark (instantly).

Misisng tooth trigger gives also better trigger issues detection.

36-1 or 36-2 is almost as good as 60-2 (to highest accuracy). EMU uses always the last available tooth for spark so for 60-2 the wors scenario is 6 degress "prediction".

12 multitooth or 12-1 is also ok (however not as accurate as triggers above).

The low tooth count (eg. 4 tooth in distributor) are the worst solution. The engine will benefit if you upgrade to higher tooth count pattern.


The EMU starts to deliver fuel and spark as soon as it is syncronised. However fuel need to vaporize that could make additional delay. So option batch all injectors during cranking can help a lot.

In BLACK you can scale the starting dose in function of engine revolution. The researches show that in MPI engine it can talk about 10 injections to get stable fuel vaporizations. To overcome it the first injection should be higher then next one, and so one. In DI engines the mixture should ignitie in first injection so DI engines starts even in half of revolution.

[nickbmw]

Can you do something for us F20C owners with the 12 tooth crank and 4-1 x2 cam to improve sync speed? It really takes a lot of cranking to start the engine. I have spent hours and hours trying to improve it with the options available but nothing helps.

[Jadzwin]

I will think about synchronising from both cams.
Other solution is to cut on tooth on ckp trigger wheel to make it 12-1

[nickbmw]

I will think about synchronising from both cams.
Other solution is to cut on tooth on ckp trigger wheel to make it 12-1

Let me know if you need any help with trigger scopes and testing.
I initially wanted to install the 06-09 DBW S2000 crank trigger which is 12+1 like the K series, the only thing preventing me is that if for any reason i have to use the stock ecu it will not work

[GearTech_Greece]

I will think about synchronising from both cams.
Other solution is to cut on tooth on ckp trigger wheel to make it 12-1

I have tried it but it does not work These are high compression engines and there is a problem with missing tooth detection on cranking. I played quite a lot with settings and filters and I gave up. Let alone changing timing disc on the S2000 is a couple of hours of work. If you could use the second cam trigger it would be perfect and a strong selling point for the S2k community.