I added a Dough Thorley Tri-y and did not see it's full potential till I went 2 1/4 all the way back with a Magnaflow (Strait through design). It was too noisy but I like the performance. Got tired of the noise and went to the local shop and got new exhaust that looks just like OEM. Much much quieter. Problem is I now have that same "sock in the mouth" feel that I opened the exhaust up to relieve in the first place. Important to note here: I have stage 2 cam, OS stainless valves, beehive springs and a medium port on a 20R/22R hybrid. It seems to me that the shop that did the work exacerbated this effect by making bends that make the pipe smaller.


When I have money to do it again, I think I am going to add a high flow cat and return to the Magnaflow. It is my understanding that the cat will act as a resonator and make it quieter than with just the Magnaflow.