this is the first time i visited the ford side of this site, but anyways, i helped my brother fab up a rear mount turbo on his 2000 F150 with a 4.6 in it, and it seems like whenever he drives it hard, the plugs fail or something, thats what happened the first time anyways, it started to knock bad, he took it to the dealer and said there was a plug that closed shut.. replaced it and it ran fine for awhile, now it did it again after he drove it hard the night before, should we be running colder plugs with the forced air???

 

You should definitely be running a range or two colder with the new plugs.

 

is that the reason why its failing plugs though?

 

are they the right plugs? never heard them closeing shut unless the piston is hittin them

 

what's the specs on the motor, what plugs were used and how much boost is the truck making, what fuel mods? is the tune aggressive or mild, is it intercooled??