I got this problem with CP piston. this is 2nd time it happen. It happen on the intake side for 3 of the pistons. Do you have any idea what is the cause of this problem. Is that a bad tune or the piston itself got problem? This problem happen only when i try to boosting 28psi. Here some of the picture for the piston. A little bit specs for the engine - B18C, 82mm CP, GT3082, 1200cc FIC injector. Boosting 28psi - 540whp.

 

the last picture is CP 83mm with the design of the valve pocket is a bit different compared to 82mm.

 

Looks like your tune is lean in certain areas of the map. I think you already knew the answer to this. Kinda hard to believe that you have that high of power and dont know **** about it.

 

Second time you have broken your pistons? Wow, people go year and years with no issues. Tune, engine build, etc. What size valves are in there? What valve springs? Post your IG, fuel, etc. maps and logs.

 

lean...

 

detonation?

 

I'm guessing he tuned it himself.

 

Bad tune,lean,detonation,engine temp to high,air temps to high,piston to bore incorrect,turbo to small,to much back pressure, take your pick bad info to start with but its not a CP problem.
What fuel are you using?are you using EGT's for tuning or just AFR's,what cams dude the list goes on and on.

 

i guess i found the answer for this... its a PTW clearance incorrect.. the engineering shop that i sent my block to bore make it smaller than the value recommended by cp...damnn...
uncle, i'm using ron97 fuel and afr is about 11.5.. this thing only happen when i try to boost it more than 28psi..

 

this thing happen on dyno run and the afr is 11-11.5...

 

Stick E85 in it and it will live.