alot of things,what year is your car or I mean how many miles on it,how do you drive it,easy or hard,you dump the clutch alot...the list goes on.For example in '06 it was about 35 degrees outside and because of an emergency I jumped in my car,no warm up time at all and I hit it...reved to about 4.5k on the tac and the TB went...and when I mean went,I mean lil BB's everywhere,never seen one go like that and I only had about 45k on it with original clutch...and no I dont drive hard.just on ocasions do I stomp the go pedal.