What kind of situation requires changine the counterweight? I just ask cause I have a s4 n/a block and s5 TII tranny w/ s4 TII flywheel, clutch/pp. I've read the cw is attached to the flywheel, and I didn't mess with that jazz when I swapped the TII stuff in. The car seems to vibrate something crazy anwhere north of 5k. Seems to coming from the front of the car, rather than the rear. Justwondering if I am running the correct CW. Even further, the flywheel I am running came off a j-spec, are jspec auto/turbo CWs different? How would I know?