This is turbo H22 ca. 15-17psi of boost. Mahle Gold 9.5:1. Tuned. Ignition very mild. And after a couple weeks a lot of blowby and the engine is in this condition like on the picture.
What could happen? Lots of detonation near intake valves...

 

High intake temperatures, low octane fuel? You could try water/meoh injection. I've seen some people set this up to activate with vtec.

 

Are your spark plugs whiter than enimem?

Could be your tuning/ignition timing.

Have you asked your tuner what could be causing your detonation?

 

fortunately it's not my engine

 

UM, yeah. That would be detonation. If you are getting lots of blowby then you have probably toasted the rings too. Judging by the scoring on the cylinder walls I would would say you have. Good thing is, you caught it before you melted a piston. How does the head look? If the pistons look like that, the head probably doesn't look much better. What size injectors and what is the DC? this is what happens when you don't catch it in time. It's the results of a faulty injector on a 7mgte, but you get the point.