my setup is basically a jrsc with 6psi and upgraded fuel pump, lately I haven't had any problems but few days ago while doing some pulls in second at low boost I hear this metal grinding sound from the engine it is random but I can't seem to figure out what it is could it be detonation?

 

Does the sounds your talkin about only occur for a second or 2 and then dissapear as you enter boost. Ive heard that a few times on my teg and can't figure out what it is either.

 

excatly it goes away after few seconds then it wont happen for a while..