Here's an example of a vehicle with maxed injectors at a measured 97% IDC, it is not an LS1 (a Nissan SR20 Turbo in fact), and it clearly shows that once the IDC has hit the highest point, the AFR goes from 12:1 to mid 13's.
Notice the available time to open the injector, and the actual time open, and see that there is no more time available to open the injector.
If you look at it from a perspective of Injector Pulse Width versus Rpm, there is no such thing as anything over 100%IDC.
If as people report that if they go from 100% top 120% IDC as reported in Scanning software and the mixture goes richer, the 100% reported in the scanning software can't be an accurate 100%, so you need to find the true 100% IDC.

 

Injector PW dropping after max VE would also explain the AFR going lean.
A drop in fuel pressure would also explain the AFR going lean.
A significant increase in chamber temperature would also explain the AFR going lean.
A high speed misfire would also explain the AFR going lean.

IMO you'd have to richen up that area in the tune to a very high degree and then record what happens to the AFR. It would also need to be repeatable on another vehicle.

The chance of the software misreporting the DC is definately a possibility, but would lead one to think that the reported PW is higher than the actual PW at the injector.

 

These injectors were maxed out, they could not be opened anymore by software used to tune it (Apexi Power FC).

That's possible, but didn't happen is this case, if needed it could be monitored by the software.

Once again possible, but all things that could induce this problem could be monitored, Boost, Fuel Flow (supply & Return), Fuel Pressure, EGT's etc can all be monitored if needed, but the person who dyno'd this car has done more than enough to know that the rising AFR is solely a product of insufficient Fuel Supply do to the injectors being too small for the job, that's why their maxed out.

Once again possible, but if it was that bad it would effect the Power/Torque traces, theres always at least 2 symptoms for a cause.

As stated, the injectors could not be opened any more, but I'm sure if it had more fuel pressure, it would have a better AFR. I have access to many more examples of this happening, so it is by no way a one off occurence. I'll see if I can get my hands on some single turbo or blower LS1 examples next week to show it can be on any sort of vehicle.

Thats true, I'll try to compare them for you and let you know.

 

You lost me there. The software should always be able to calculate higher PW numbers.
Looking for only examples that support a theory is false science. That wouldn't show repeatability on other cars at all. Don't bother showing more examples of the same thing with inconclusive situations.
Why is it that your software will not command higher PW numbers?
I've never seen a system that will not do this.