hi there i am new to this forum and only had my scooby a about a month but i have a problem its a wrx 1993 import and the problem is when i am driving along if i put my foot down it starts to stutter,judder and hesitate when it gets to about 4-5 k on the rev counter it only does this if i accelarate hard not when i do it gradually can anyone tell me why please ????????? also the dump valve starts to chatter and release boost pressure the clutch also slips but i am getting that replaced next week is this related