Timing Drift Issue

[WCCoffey]

I am having some issues with the ignition timing.

FYI, I am not a tuner, I am a well versed and knowledgeable mechanic, but definitely no tuner.

I got the car up and running good enough to take it to a tuner and he was supposed to take it from there. He found that the timing drifts 5 degrees retarded when you have the timing locked down. He couldn't fix it so apparently he just tried to tune around it. After I started messing with it I find that the car breaks up a bit at maybe 10-20% throttle and can see the timing kinds goes berserk, if I add a little more throttle the timing smooths out and the car runs great. The car doesn't make very good HP, but has very good drive ability. The car has been endurance raced several times like this (nearly 30+ hours of racing), as I was unaware there was an actual issue.

I am having a new tuner come retune the car and hopefully correct all of my tuning issues and squeeze some more hp out of this thing. He is a VERY accomplished tuner and I'm flying him in to do 4-5 cars for my race team and my own personal car. All I want to do is resolve this timing drift issue, so this tuner can focus on just tuning the car and not have to worry about trouble shooting the car.

To me it seems like there is a correlation issue for the pick up on the crank or cam shaft. Whether it be polarity or rising/falling.

I was playing around with the primary trigger and got the following results:
Changed from rising to falling, car runs very poorly, timing drift still present
Changed polarity of sensor, car runs very poorly, timing drift still present
changed polarity of sensor, changed from rising to falling, car runs fine, timing drift still present.

So it seems to me the problem is in the secondary trigger. Does that seem right?
I am however unsure as to how to resetup the timing after making a change to the cam trigger. The crank is a 12-2 and the cam is a single tooth. If I change the trigger from rising to falling the timing is so far off it will not start. So I left it at that, and now I'm looking to get some help.

Like I said, I am not trying to dial anything in, just trying to get rid of this timing drift so the car can be properly tuned.

[WCCoffey]

Some additional Info..

The cam trigger is right where it should be directly in between 2 primary triggers, but when I rev it, it moves a little.
Seems like this COULD be normal with a timing belt motor because of belt deflection/stretch but unsure. The motor has a brand new gates racing belt on it, thats hard as a rock, so I'm not really sure that its stretching...

This image is at idle.

This image is off idle, maybe around 3k rpm

The timing is pretty consistently off 5 degrees when reving it off idle, it doesn't seem to fluctuate or change any more or less than that.

I was unable to replicate the "breaking up" i experienced at 10-20% throttle while I had the scope active.

[Karel]

if you cant change edge, you need to change polarity physicaly.
Did you play with input delay ? on primary trigger

[WCCoffey]

I have not played with the input delay as I am not sure what this does and its effect exactly.

I'll try doing the same with the cam trigger as I did with the crank trigger to see its effect.

[WHPZach]

When you change the primary trigger from rising to falling, you'll need to check timing and reset your trigger angle, as you're probably moving "TDC" as the ECU sees it by a full tooth. What does the timing light show when you change the trigger edge?

Also, can you attach a log so that we can dig further into what the ECU is seeing when it has issues at part throttle?

[WCCoffey]

When you change the primary trigger from rising to falling, you'll need to check timing and reset your trigger angle, as you're probably moving "TDC" as the ECU sees it by a full tooth. What does the timing light show when you change the trigger edge?

Also, can you attach a log so that we can dig further into what the ECU is seeing when it has issues at part throttle?

When I changed the primary trigger edge I didn't bother resetting the timing because all I was doing was trying to check the drift.

The timing light still shows a drift, I didn't record how much the timing changed by moving the edge.

I will work on getting a log tonight, but I want to focus on the timing drift as that is a constant issue that needs to be resolved asap and the break up seemed to only happen a couple times and has not done it again since, but seeing as it could be related I'd like to go down every avenue.