Looked exactly like not enough ring gap. That's what it does to pistons. Its a big risk to boost without adding gap. Some get away with not doing it. Some fail if no gap is added. Its too expensive to gamble with it. When the gap closes fully it pops up and breaks the piston. Boost closes gaps quicker due to increase heat and pressure
No, I found a small screw in the cylinder. The turbo finished it off. I didn’t get into boost before it went, I was doing a dry run to make sure all my fittings were not leaking. We have two of these turbo’d cars and the other one is building 10lbs and getting beat on daily with no tune. Which leads me to believe I had other issues before I started, this car has been in two accident and totaled both times.
