After I installed the front pipes, I can now hear the turbo whistle in low rpm before induction noise takes over. I can't comment on having just the 3-inch cat back as I have a high-flow cat as well, but there is definitely a difference to be had. Much smoother airflow and less restriction means the exhaust gasses can get out quicker, which improves everything really, except heat output, but that's no cause for concern.
wel im getting a set made up by a mate who has his own exhaust shop so should be interesting his is going to go 2.5 inch from the flange and into high flow cat. i hoping to notice a differance oh and he is only charging me $400.
so should i expect louder induction noise and turbo spool? faster spooling , and more responseive?