alright i have garret t3 t4 hot .63 cold .60 60trim. just built outlet and intake pipes for it 3 inch in and 21/2 out allthe way to intake. ok heres the ? before i set boost to 10 psi. works great. changed routing of icpipes and size finished last night. Got on it after all warmed up. went to five then jumped to 20 and then ALL SORTS DETONATION. making the pipes bigger make that much of a difference?? all fingers point to yes but just wondering if anyone else has heard or seen this before.