i have had some problems with detonation with a 3tgte even at very low boost, this seems to be quite a common problem. I have heard that the factory fitted cars had some sensors on the fire wall that stopped it. I have no idea how!!! but this would explain alot of busted pistons . I have just finished a rebuild with forgies with a comp of 7.5 -1 and will be fitting a inter cooler to try to stop the detonation but pervetion would be a lot better than a cure.