so that's detonation?

 

Ill see if I still have the pistons from the f20... but it was a little detonation for a long time that lead to reallllly high egt's and then a lot of pre-ignition. The rings were blasted into a million pieces and the pistons were severely melted.. so bad that parts of the cylinder walls were melted.

 

rofl

 

i'd like to know why you would retard the timing more at lower rpm then high?