The BARO sensor from the log says you’re at 81kPa barometric pressure – that’s pretty low, you must be at some altitude

The reason your car is trapping low and not picking up much power is because there is no air where you’re at.

From the factory, GM sets these cars up to make a certain amount of power at the wheels, and gives wide discretion to the turbocharger to adjust to meet these targets.

This means the car will make 260HP at sea level and 260HP at high altitude simply by modulating the amount of boost from the turbo.

Because of your altitude, the turbocharger may be working close to its limit just to make 260HP.

In custom tuning, we change the rule to say “Make x amount of boost all the time, regardless of how much power that is.” This results in spectacular gains at sea level, where the turbocharger is relied on much less, but the higher you go, the less of a difference in power you will see because the stock tune is using the turbo much more.

The logs show you are hitting 100% turbine speed. I can’t make the ECM make the turbo spin any faster than it already is. There’s a good chance it’s very close to spinning that fast even on the stock tune due to your elevation. So, when people say you should be trapping 106-110MPH, they are correct – IF you are at low elevation. And you would.

Well, for comparison sake, tuned Cobalt SS cars will make up to 260kPa of absolute manifold pressure at sea level. The highest spike is 235kPa at your altitude and sustained looks more like 220kPa.