As posted above, I would only experience this problem after the ECU was in closed-loop. I went out and made several short acceleration runs to datalog the problem. I'm not sure if this will help, but here is a datalog of a typical stalling event on my car (before we updated the chip...)
The graph below shows TPS volts and RPM. At about 0.87 seconds, I accelerate moderately from a stop. You can see RPM's climb through first gear and then shift into second gear at around 4.5 seconds. I then let-off the gas at about 5.3 seconds. You can see RPM's drop and the stall occur at 7.46 seconds.
The second graph shows MAF and Injector PW. At the time I let-off the gas (5.3 seconds), you can see the MAF reading oscillating back-and-forth as the turbo goes into surge ("flutters"). This causes flow reversions in the MAF pipe, which messes-up the MAF reading. Just about the time the reversions stop at 6.64 seconds, the engine stalls - things have gotten too screwed-up for the ECU to save it. Note that injector PW climbs rapidly near the end - more on this in the next graph.
Finally, here is a graph of O2 sensor volts and ECU commanded F/A ratio. The O2 volts start-off rich at the hit of the throttle, then the O2 volts oscillate back-and-forth from about 3.35 seconds until I let-off the throttle at 5.3 seconds (the ECU is running in closed loop, so this is normal). Right after I let-off the throttle, the O2 sensor volts go VERY high (over 800 mV) initially - likely the ECU is responding to the wild MAF readings by putting in too much fuel. However, as the engine RPM's drop, the O2 volts go VERY low - well under 100 mV. At this point, the ECU thinks the engine is running very lean, so it starts trying to add a bunch of fuel (thus the spike in injector PW in the previous graph). In reality, the engine is probably not firing at all, so it's shooting unburned fuel and oxygen out the exhaust, causing the false lean O2 readings. At 7.46 seconds, the engine stalls.
The problem is this: with a Scanmaster, you're only going to get data about once per 1.5 seconds (if I remember correctly). So, you won't be able to see these things happening. I guess you can try to see if you scanmaster is showing very low O2 volts just before the stall, or maybe you can get enough data frames to show the MAF reading oscillating back-and-forth when you lift off the gas.
Your combo is significantly different than mine - especially the turbo. Most of the people reporting these types of problems have small turbos like my TA49 or a TE44, at least as far as I know. Your problem might very well be caused by something else. At least this data might give you some things to look at and consider.
Bob is an incredibly smart guy, so I'm sure you guys can figure it out. Maybe the above will help a little.
Good Luck,
