Magnetic crank trigger?

[art leong]

Here are the instructions on how to set base timing. I'm starting to think I was told wrong by the guy that installed the unit.
He told me that I was setting the cam position sensor timing, and that it was telling the ecu that when it got the signal the next signal from the crank was tdc firing.
With the old software they put a timing light on the crank trigger to set it.
When I advance or retard the intake cam (where the cps is) I have to reset the offset, Even though I didn't touch the crank sensor or wheel

Here is a copy of the instructions Thanks

Once the correct Triggering Mode has been selected and Triggers 1 and 2 configured, the trigger timing must be calibrated by checking the ignition timing using a timing light. Doing this tells the ECU where the trigger signals occur in relation to engine position.







To Calibrate Triggers



1. In the Triggers->Calibrate menu, click the Set Base Timing button . This will open the Set Base Timing window.



2. While the Set Base Timing window is open, timing is locked to a constant value.



3. Enter the ignition timing value that you want to see with the timing light in the Lock Ignition Timing To: value. This value will depend on the location of available timing marks. 0 (TDC) and 10 deg BTDC are the most common values.




4. This step depends on the instructions shown in the Set Base Timing window.


· Adjust Offset until Ignition Timing matches the number above. Alter the number in the Offset setting until the timing light shows the number entered in the Lock Ignition Timing To: setting. Increase this number to advance ignition timing. Decrease this number to retard ignition timing.




· Adjust CAS until timing matches the number above. Mechanically rotate the position of the crank angle sensor (or distributor if it contains the CAS) until the timing light shows the number entered in the Lock Ignition Timing To: setting.




5. Click Done to keep the new Trigger Calibration settings. Otherwise click Cancel to restore the previous values.



6. Perform a STORE to permanently store the new trigger calibration setting to the ECU.

This explains trigger offset.
The Trigger Offset is used to calibrate the trigger timing so that the ECU can calculate the correct engine position at any time.



Trigger Offset is defined as the offset between TDC (between compression and power stroke) on cylinder number 1 and the first trigger event on Trigger 1 that occurs after the sync (Trigger 2). Therefore if the sync occurs and the next tooth on Trigger 1 passes the sensor at exactly TDC no. 1 then the required trigger offset will be 0. If this is not the case (and it typically will not be) then a non-zero Trigger offset will be required.


Although the trigger timing affects both fuel and ignition, it is easiest to calibrate the trigger timing by getting the ECU to try and deliver the ignition timing at a fixed angle (e.g 10deg BTDC) and checking that the ignition is actually occurring at this point using a timing light. This procedure is described under Trigger Calibration.



Note: As off Vi-PEC Tuning Software V4.4.0 and later this setting can only be adjusted in the Set Base Timing Window

[buzzinhalfdozen]

Seems somewhat confusing to me. I understand setting the offset to correct for "requested" timing versus actual timing checked with a light, however the next step of moving the crank sensor baffles me, why would that need to be moved you just corrected any errors with the offset function! Joe BTW how many triggers does your cam sync have? OK after reading the last part of your last post I see what they're doing, the offset they're referring to is between the crank and cam sensors. Then you physically move the crank sensor for Ign. timing error sorta like changing the timing on an MSD crank trigger set up. I was confused as my system uses the offset to correct Ign. timing event errors. Based on what you're saying I can assume your crank trigger wheel does not employ a "missing" tooth design?

[art leong]

My plan is to use the set base timing function. And adjust the trigger wheel to match what offset is in the ecu now. It was running good.
But when I put the timing light set at zero. On my balancer/trigger it shows the tooth past the center of the pickup. My tooth to tooth distance is about 1 inch we take a 60-1 wheel and grind 2/3 of the teeth off this makes it 20 teeth evenly spaced.
We originally tried using it as it came but it would break up past 4000 rpms. Proving what you were saying about the size of the magnet.
I'm the type of guy that wants to know why it works. So if I have a problem it will be easier to figure out. Plus if I have to build it again I can duplicate it.