Primary trigger configuration

[Tomba]

Hello everyone,

I need some help with setting up the primary trigger configuration on a BMW M30 engine with S38B38 crankshaft.
I have added a pdf file with the current setup.

Could someone tell me the right settings which I should use?

To me it seems that:
First trigger tooth = 18
Trigger angle = "how many degrees before TDC is the trigger tooth" = tooth 11, 18-11=7, 60-7= 53 * 6°per tooth = 318°. But the settings go until 120°....

primary trigger wheel is 60-2 and VR sensor. Secondary will be 1 tooth (magnet) with VR sensor (S38B38 style). Any suggestion for when the secondary should occur? I can now still change the drawings.

Please help! Engine starts but can't get it running.

Best regards,
Tomba

[Maciekx]

On which tooth there is TDC of first cylinder?
First tooth after "-2" brake on toothed wheel is numbered as "0".
360 deg/60 teeth = 6 deg per tooth.
For ex. if tdc of 1 cylinder is at 17'th tooth (exactly at 18'th but 17 counted from 0)
and max posibility of ignition advance would be 60 deg, the first trigger tooth is 7.
First trigger tooth + trigger angle = tdc of first cylinder.
If your pdf is correct, and first tdc is on 12'th tooth, you should have:
1'st trigger tooth = 2
trigger angle = 60

2'nd trigger = 1 tooth. Scope should look like this one from the newest emu instruction.

[Tomba]

On which tooth there is TDC of first cylinder?
First tooth after "-2" brake on toothed wheel is numbered as "0".
360 deg/60 teeth = 6 deg per tooth.
For ex. if tdc of 1 cylinder is at 17'th tooth (exactly at 18'th but 17 counted from 0)
and max posibility of ignition advance would be 60 deg, the first trigger tooth is 7.
First trigger tooth + trigger angle = tdc of first cylinder.
If your pdf is correct, and first tdc is on 12'th tooth, you should have:
1'st trigger tooth = 2
trigger angle = 60

2'nd trigger = 1 tooth. Scope should look like this one from the newest emu instruction.

Ok thanks Maciekx!
My pdf is exactly as the current set up has been.
I will try it out. I had my first trigger tooth on 18 and angle on different settings which didn't cause the engine to start. I thought it must be timing relevant as the engine didn't start with any kind of injection duration.

Will report soon!

[PSI-Motor]

First trigger tooth 5. Angle 54.

[Angelo S38]

Hi Tomba,

Sorry for the offtopic, but are you by any change active on M5 board as well?

Regards,
Angelo

[Angelo S38]

Hi Tomba,

I've taken a look at my triggerwheel setup last night it's a S38B36 but I think yours wil be similar. I believe the settings from PSI motors are correct.
My sensor is located at tooth 14 with cylinder 1 at TDC.

Regards,
Angelo

[Tomba]

Yes I am Angelo.

Hope to check the settings this week. Otherwise it will be next weekend. I am going on holiday!

[Tomba]

First trigger tooth 5. Angle 54.

Could you explain the settings?

If I count from tooth 5 from missing tooth I come far after the TDC mark with 54°.

[PSI-Motor]

5 x 6' = 30' + 54' = 84' before tdc

[PSI-Motor]

Bmw 6 cyl has two settings in general. The one above and The second below.

First trigger tooth 45 and trigger angle 54.

[Tomba]

But my engine uses a trigger wheel from M30 and a crankshaft from S38 which reference point and sensor position is not equal to the M30.

smash my brains with a hammer, I still don't get it !

I don't see the relation with the cranksensor and TDC in any given explanation.

[astra vxr]

try this

[PSI-Motor]

If you have 18 tooth trigger.

Fill in.
Trigger tooth 10 and 48 degres.

[Tomba]

Or 9th tooth and 54 degrees?

max advance of 48° seems a bit to the max edge on a 7:1 compression ratio engine in cruise...

[Angelo S38]

This is how I believe you determine the settings, (all theoreticly as I haven't got an EMU yet):

1 Place cylinder 1 on TDC

2 Count the number of teeth which have passed the vr-sensor up till that point. Counting from the two missing teeth, the first tooth is numbered 0.
In my example photo above tooth 14 is at the sensor when cylinder 1 is at TDC. So 15 teeth total since we're including 0

3 Take a amount of ignition advance you'll never reach, for example 54 degrees triggger angle.(always a multiple of 6 since 360/60=6 degrees per teeth for the 60-2 trigger) This equals to 9 teeth since 54/(360/60)=9 dertermine trigger tooth 14-9=5

4 Check if each following ignition event doesn't coincide with the 2 missing teeth. Ignition event spacing on a 6 cylinder 720/6=120 degrees or 120/6=20 teeth trigger tooth for next event is 5+20=25
25+20=45 45+20=65 etc.

If it does coincide, you have to choose another setting.

I hope I'm correct and that it's helpfull.

Regards,
Angelo

[Jadzwin]

Angelo your explanation is perfect...

I use simplier method Just take timing light, enter 60 for trigger angle and modify the first trigger tooth to get spark exactly at TDC (set ingition angle during cranking to 0).
After that you have proven configuration (with timing light).

[Angelo S38]

Glad it's correct, I agree using a timing light is much easier.
But I personally like to do as much of the settings before the actual work starts, and be sure I grasp the theory.
As it's my first time I'm doing anything on the subject of engine management.

[Jadzwin]

But after that you still need to check your settings with timing light
However every way that leads to success is good

[Angelo S38]

Hi Jadzwin,
Will do

[Tomba]

Mine would be,

VR sensor position is tooth 17 counting 1st tooth as 0.
17*(360°/60 tooth) = 102°
102° - 54°(trigger angle) = 48°
48° / (360/60) = 8th tooth.

tooth 8, angle 54°
Ignition events would be 8 - 28 - 48. (straight six)
Will check it with a timing light. No need for hammering my brain I got it.
Thanks everyone!