OK

Uni is out, yesterday I went and bought my 13BT Crank Angle Sensor, laptop tuning cable for my MSI V3.0, I installed the 4.7k ohm pullup resistors, they are ready to be wired into the DB37 connector.

I also found that my LED's were in the wrong way around :O

I've decided I'm going to run a de-toothed CAS in my fresh 12A streetport.

Anyways from scrouging around on the forums and reading and reading I'm still finding it hard to find some information. Yes I've searched, so to make things simple for you guys, probably mauitaibxr anyway :P I'll post what I understand, and then ask the questions.

The 22 tooth CAS pickup wires goto pin 24 and 7 (I think its 7, but thats not the problem anyway)

I set Megatune to Generic Wheel.

Then inside Wheel decoder settings I set the following:

Wheel Decoder Base teeth=12 (this is because MS sees 12 teeth or cycle or whatever)

2nd trigger enable=off (MS doesn't trigger on a missing tooth and I'm not using the 2nd VR sensor)

This greys out the next two box's ("2nd trigger active edge" and "2nd trigger and missing teeth")

I then select Missing teeth=-1

OK heres the problem!

Can someone PLEASE explain how the trigger A and the missing teeth inter-relate. I want to understand which teeth I cut results in which trigger settings. Or if it doesn't matter then please give me a detailed and painfull explanation.

Please then clearly outline the method you would use for inserting the CAS into the motor for the outlined triggering settings and the missing teeth.

I'm ready to start more extensive testing but I want to understand what I'm doing before ruining my CAS!

Thanks guys!

Also because MS sees only a 12 tooth wheel, do I need to use the 024s9 style wheel decoder routine?

 

OK so now I know to use 024s9 decoder routine, i already found a post from maui about that.

But my question about how the trigger and other stuff still stands, I really want to understand this before I go nuking out the teeth

 

I've removed the gear and roll pin from the bottom of my CAS

I forgot to mark which side the timing allignment mark was on the CAS gear, does this matter greatly.

Another thing, do you use triggers A and B for missing teeth?

 

I'll respond to this with detailed instructions when I get home from work. I don't have time for a proper response right now.

 

Thanks mate!

I look forward to your response, possibly might be a good thing to add to the FAQ.

Again thankyou

 

The suspense!

Damn time zones

 

sorry, when I get home from work turned into when I get a chance...

Basically, just stab it in so one of the teeth from the 24 tooth wheel lines up with the VR sensor for that wheel. Make sure the engine is at the -5 mark before doing that.

So if that tooth is -5, the tooth that passes the sensor before it is 25 BTDC, the tooth before that is 55 BTDC, and the tooth before that is 85 BTDC. That's the tooth you want to cut... and the tooth directly opposite that...

Then your settings for the wheel decoder will be:

Trig A: 1
Ret A: 3
Trig B: 7
Ret B: 9


Trigger Angle: 55 deg

I'd recommend setting the trigger angle to 60 degrees however, and then when the engine starts, you can readjust the CAS slightly to compensate.

 

From reading almost everything I now understand that you can have 2 trigger inputs from one VR pickup.

And the whole Tooth one selection seems arbitrary. (ie you just choose the first tooth after the missing tooth)

The difference between Tooth 1 and Tooth 7 is 6 Teeth, which when you

6x30 (crank degrees) = 180, which is the difference is rotor phase on the crank(e-shaft). This means that Trigger B is for the 2nd Rotors spark signals.

I already know that the leading signals from Rotors 1 and 2 are added together for the wasted spark leading. That the Trailing is calculated by a using a delay.

Where does the trigger return come into the equation?

Maui If you'd like I can writeup an FAQ post about understanding the trigger options missing tooth, once I have it down.

 

HAHA I can answer my own question

Hopefully someone will benifit from my rant :P

Trigger return basically is which tooth triggers the timing whilst the engine is cranking trying to start.

So when you specify

Trigger A 1 3, and the trigger angle 60. The ECU knows that the 1st tooth is 60BTDC (for a trigger of 60 degrees)

This means the 3rd tooth for trigger return, is TDC ie used for cranking timing.

Correct adjustment of the CAS will still allow cranking timing of 5ATDC hopefully

 

yeah, but I've found that cranking around 0 makes it a bit easier to start on some engines, which is why I use that setting.

Also, there is a link in a post somewhere in this section where I explain the whole business of setting up your triggers and all that..

I've made things considerably easier in ms2/extra. There you only have to set your number of teeth, and where the missing or extra tooth is at, and it'll figure out the rest for you, and use every tooth on the wheel to set timing (as opposed to ms1/extra which only uses the trigger teeth).

Ken

 

ahhh ok sweet!

Are you writing MS2 rotary ignition code in asm?

 

some of it will be in asm, some in C...

 

I have rpm in megatune when I spin my CAS

I also have blinking LED's, which behave how I expect they would in both FC and FD mode

Maui could you please share you base ignition table for the zeal stuff please?

Again thanks for all your help, now its time to make the table, hopefully i might test teh car tomorrow

 

THE CAR RUNS BEAUTIFULLY, THANKYOU TO EVERYONE THAT POSTED HELP FOR ME

One other thing. My little bit of contribution.

OK if you are wiring 2 Bosch BIM024 ignition modules in parallel for the leading ignition then the value of 4700ohms for the LED pullup resistor might not work. Mine would not fire the leading plugs without a lower value of resistor. Currently I'm using about 970Ohms, (i just wired in a 1200ohm resistor in parallel to drop the resistance). Now it fires perfectly. The value of 4700ohms seems to be a good number for the trailing ignition pullup resistors however seeing as they are only a signal module on each output.

This was the only reason why my car wouldn't fire first go.

I have a movie to post up of the cars 2nd startup. Hopefully that will motivate others with their projects.

Again I thank everyone for their valuable help!