High flow cats?
Thread Starter
Pro
Joined: Jul 2020
Posts: 548
Likes: 132
From: Texas
High flow cats?
I have stock exhaust except for Borla S Type II. I like the sound, I just want it a touch louder. Headers are not in my future right now, so will high flow cats make it a touch louder? Thanks!
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
They probably wont make a huge difference. That said, my problem is the opposite. I bought my '97 with engine swap, big cam, yada yada. I live in an apartment complex. I got new headers and went with hi flows hoping it would quiet it down a little. Not so much, a little, but not a lot.
Now, the catalytic converter is the biggest choke point in the exhaust. Getting a hi flow will improve that flow and thus performance a bit. You can always go with a rear muffler delete or chambered/bullet axle back. The mufflers on my car have a bypass pipe from the from the muffler in pipe to the out pipe, so essentially I'm a straight pipe.
Now, the catalytic converter is the biggest choke point in the exhaust. Getting a hi flow will improve that flow and thus performance a bit. You can always go with a rear muffler delete or chambered/bullet axle back. The mufflers on my car have a bypass pipe from the from the muffler in pipe to the out pipe, so essentially I'm a straight pipe.
Instructor
Joined: Nov 2019
Posts: 162
Likes: 80
From: Central NJ
I wouldn't hold much weight in the oem cats playing a major factor in performance or sound. At the oem h-pipe sections, the cats have a different inlet and outlet diameter. Also, the inlet and outlet positions are not in line, they are slightly offset. So its not as easy as a swap as it seems. High flow cats wouldn't do enough to keep a P0420/30 engine code from being thrown. You can turn the code off with a tuning software. Still its seems like too much money and effort for little sound or performance gains.
